Vol. 45—1991 - NorthEastern Weed Science Society

Influence of Thr ee Safeners on the Herbicidal
Effe ct s of Triasulfuron l
Irena L Zbiec 2 and Robert M. Devlin 3
ABSTRACT
I n this study triasulfuron caused severe inhibition of co rn
grow th . Tr i a s u l f u r on at 60 uM caused a 69% reduction in shoot
length and a 60% reduction in shoot dry weigh t . \iith the addi ­
tion of l mM of BAS-145l3 8 t he percent decreases in shoot leng th
and dry weight were 35 and 33%, respectively . Similarly. corn
roots were a lso part ial ly p rotected by BAS-145l38 . Di c h l o r mi d
and R- 29 l 48 also afford ed pa r t i a l protection to corn fr om the
her bicid al a c t iv it y of t r i a s ulf u r on . For example , shoo t le ng th
was re du c e d 32% by 20 uM tri as u l f u r on but onl y 10% when 1 roM
d ich lo r mi d was also add e d . Alt hou gh compl et e p r o t e c t i o n of c o rn
f r om triasul fu ron wa s not given by BAS- 145 13 8 , d ich lor mid , or R­
29148 , the result s o f this study o ffer hope that su c h prot e c t i o n
may be found i n t he near future.
I NTRODUCTI ON
Su lf ony l u r e a her bicide s represent a re latively new , highly
activ e cl a ss of herbicides. The development of safeners to a llow
broader use of these compounds in corn (zee ~ L .) a nd / o r sor ­
ghum (So rghum bicolor (L.) Moench. ] culture would be most useful.
Howeve r . r es e a r c h on safen ers for sulfonylurea herbicides has
been limit ed .
The s a f e ne r NA u . 8-naphthalic anhydride) has been shown to
hav e good safening activ i t y against chlorsulfuron l2-c hloro -~- [ [
(4 -methoxy -6 -methyl -l , 3. 5-triazin -2 -yl) amf no l carbonyl} benzen esul ­
fonamide }in corn {2 .4 ,5 .6} . Good protection by NA an d partial
protection by cyometrinil { ( Z ) - d ( {cyenome t ho xy) imino} ben ­
zeneacetoni trile} to sorghum treated with chlo r sulfur on has been
obse rved (3 ). Devlin and Zbiec (1) have shown that BAS-145 13 8
can par t ially protect corn from the sulfon ylu rea herbicides
chlorim uron {2- [ [ [ [ (4- c h 1o r o - 6- me t hoxy - 2- py r i mi d i ny l) ami nal car ­
bonyl } a mi nal su Lf ony k l be n z o Lc acid } , ch1orsu1f uro n , and su1 ­
f omet u r on [2- ([ [[ (4 , G-d i me t hy 1- 2-p yrimid i ny 1 ) a mi no ] carbony l]
a mino }sulfony l ] benzoic acid}.
1/ Pa per No . 3000 . Mas sa chusetts Agric ul tural Experiment
Sta tion . Unive rsity of Massachusetts at East waxeham , This
r es ea rc h project is support ed from Exper iment Station Proje c t
No. 629.
2/ Visiting scientist. Academy of Agricu lt ure . s acaec Ln , Poland .
3/ Profe s sor , Labo ratory of Experimental Biolog y , Cranberry Ex ­
periment Station . Univ ersity of Hassachusetts. East Wareha m.
MA 02538.

In the p re s ent study t he safening effects of the s afe ne rs
BAS- 145 138 , di ch1orm id , a nd R- 2 914 8 in co r n t re a t e d with triasul ­
fu ro n we re obse rv ed ..
MATERIA LS AND METHODS
Co rn s e e ds were s o ak ed for 6 h in 1 roM solut ions of BAS- l45 ­
l3B, d ichlormi d , or R- 29 14 B.. The s ee d s we r e then so wn i n 9-cm
styrofoam pot s OS s e eds per pot) f ill e d with moist v e r mi c u l i t e
t hat had b e en p r ev iou sl y treated on the suface with 5 ml of 0 ,
20 , 40 . o r 6 0 uM of t r ia s u l fu ro n i n wa t e r . The herbicide solu ­
tion wa s app li e d as a f i ne spr ay usin g a small atomizer at 10
kPa. The se ed s we re co v e r e d with about one ern of untrea ted mo i s t
ve rm i c u l i t e . Pe t r i di s h h alves were u s e d as hol der s for the pots
to cat ch d raina ge an d a s an indi r ect way to provid e wat er and
nutrients.
condi~~~n~l~~t~i ;~~e {i~~w~E i~_~s§!I~Wi~ ~h~~~ ~~~e~ ~o~: ;: f ta nd
temp e r at u re (2 2 laC ) . Afte r sho ot e mergenc e , 3 0 ml of 0 .5
s t r e ng t h Hoagla n d s olu t i o n was a p p l ie d daily to e a c h pot via the
p etri d is h ho l de r s . After 12 days t he se edlings were re moved
from t h e po t s a nd t h e r oots t horou ghl y wa sh ed. The 10 larges t
s e ed l in gs (dete r mine d by sho ot length) fro m each pot were
sele c t e d , and t h eir s hoot length , ro o t le ngth , fresh weig h t , and
d r y weigh t dete rm ined. All experiments were r eplic at ed f o u r
ti mes an d the d ata s ubj ec t ed t o analy si s o f v a ri a n c e .
RESULTS AND DIS CUSSI ON
Growth of c orn was severly i nh i b i t e d by tr iasu l f uron. In
t he BAS-14513B expe r im en ts s ho ot le ngth o f corn trea ted with 20 ,
40, and 60 uM triasulfu ro n was reduced 50, 57 , and 73% , respec ­
ti ve ly (Table 1) .
I n th e d i c h l o rmi d and R-29 14B experiments simil ar inhibition
o f sh oot l e n g t h by t r i a sulf u r o n was observed (Tabl e 2 & 3 ). As
e xpe ct ed , f resh we i g h t a nd dry weight of both roo ts and shoots
wer e al so reduc ed by tr ia s ulfur on (Table 1.2 ,3) .
BAS-14513B e xperi ment .. Shoot length of corn treated with
2 0 , 40 , an d 60 uM triasulfuron wa s reduced 50, 57 , and 73% (Table
1) . In th e pre sence of 1 mM BAS-145 l3 B tr iasulfuron was c onsi
derabl y le ss ef fe ctive , th e a for e - men t i one d r e d uc t io n s rea ding
14, 26 , an d 35 % (Table 1). S i mi l a r s afeni ng a c t i on wa s a lso
no t e d when s hoo t fresh and dry weights were me as ured. Fo r ex ­
amp l e , at 40 uM t ri a sulfur on shoot fres h and dry weights were
do wn 57 an d 34%, re sp ec t iv e l y . With t he ad dition of 1 mM BAS­
14513B, sh oot fres h a nd dry we i g h t s were only inh ib i ted 19 a nd
7 %:, re spe ct ively (Tab le 1). Root gro wt h wa s also p a r t i a l l y
p ro t ec t ed by BAS-1 4 51 3 8 f ro m t he herbici dal acti on of t riasulf
ur o n (Tab le 1) .

Table 1. Safening influence of BAS-145 138 IBASI on herbicidal
effects of Triasulfuron (HERB) on the growth of corn.
SHOOTS i Rc>D""TB'""--- l
HERB BAS ! . Length . Fr Wgt ! Dry Wgt , Length ; Fr Wgt 1Dry ·Wg t
(uM) ImMl ! (mm] (mg/pI) : (mg/PI ) ! (nun) (mg/pl) l (mg/pI) I
- 0---
i
0 181 623 44 176 . 508 1 38 !
20 90 337 32 88 171 21
20 155 531 41 164 406 33
40 78 271 29 67 109 15
40 134 504 41 147 275 26
60 48 172 17 42 109 17
60 117 415 36 128 210 23
LSD 5% 4.0
26 2.9 13.9 I 34 I 3.0 I
1% 5 . 4 36 3.9 18 .9 t 4 6 j 4 . 0 :
' J -1..-..-- '
Dichlormid experiment. Shoot growth in leng th of corn
treated with 20 , 40, and 60 uM triasulfuron was inhibited 32 , 45,
and 70% , respectively. With the addition of 1 roM dichlormid ,
these r e duc t i o n s were 10 , 20, and 27%, respectively (Table 2).
Shoot fresh and dry weight reductions caused by triasulfuron were
also offset by dichlormid. For example, 60 uM dichlormid reduced
shoot fresh weight 63% and shoot dry weight 48% (Table 2).
However , with the addition of 1 roM d ichlormid fresh weight was
only reduced 11% and dry weight was similar to the control (Table
2) . Safening action of dichlormid in triasulfuron-treated corn
plants was also apparen t when root length , fresh weight , and d r y
weight were measured (Table 2) .
Table 2 . Safening influence of Dichlormid (DICHL) on herbicidal
effects of Triasulfuron (HERB) on the growth of corn.
SHOOTS
HERB DICHL - -Le ng t h \ Fr Wgt "Dr-y Wgt ,
(uM) (roM) (rom) (mg/pl) (mg/pl)
1 87 587 50
20
20
12 7
168
458
594
47
53
128
189
238
542
27
46
40
40
102
150
382
574
43
55
122
i 178
194
376
23
36
60
60
LSD
I
5%
1%
57
137
8.3
11.0
220
523
44
60
26 ! 71 136 20
53 1 148 260 28
4 . 9 i 18 -1'--5-2- -- --;:-; ---
~~__J_~_~.~ ~_ . __~ _ ~_._ 7

R-2914 8 e xperim ent. Shoot length of corn t r e a t e d with 20 .
4 0. and 60 uM tr iasulfuron wa s inhibited 35. 48. and 6 5%,
respectively. Whe n al so trea ted wit h 1 roM R-29148. i nh i b i t i o n s
of shoot l ength we r e 1 5, 21, and 28%, respecti vely (Table 3).
Strong _safening ac tion was observed when shoot fresh a nd dr y
weigh ts were measured . Corn plant s t r e a t e d with 20 , 40 , and 60
uM triasulfuron had shoot fresh weight inhibited 29 , 44, and 6 5%
and shoot dry weight inhibited 17, 27 , and 56%. resp e ct ive ly
(Table 3) . However, with the add ition of 1 roM R-2 9 148 f r e s h
weigh t reductions we r e 5 , 9. a nd 19% an d d r y we ight red u c t i o n s
were 0 , 0, and 5%, respective l y (Tab l e 3 ) . Roo t gr owt h i n
tria su l fu r on- t r e at e d cor n p la n t s was als o pr o t e c te d by R-29148
(Table 3) .
Tab le 3. Safe n in g inf luence of R-29148 (R-29) 00 he r b icidal
e ffe cts o f Tr i as u l f u r oo (HER B) on th e growth of corn .
,- - - -----r - - -- S - H - 0- 0 T'~S---...,.-----.:-~~;;-;,,-- ·
~ER B R-29 . Le ngt h ; Fr Wg t ' Dr y Wg t
( uM) ( mM) (mm) (mg /p1) (mg /p1)
I Le n g t h ,RF~ ~g~ Si Dry Wgt l
I (rom) : (mg/pI) (mg /pI) I
'- -- ---- ------- - -- ,- -- - -- - ----- '
144 5 18 41 13 6 56 0 42
20 9 3 367 34 124 244 2 5
20 12 2 490 42 146 406 35
, 40 75 288 30 104 17 3 2 1
40 114 473 44 14 6 3 10 32
60 50 179 18 134 17
60 104 421 39 282 28
LSD
I
5% 7 .6 24 i 3 . 0 34 1.7
1% 10 .4 32 I 4.1 46 2.4
It i s apparent f rom t his st udy t h a t BAS-1 4 5138, di c hl o rm i d,
and R- 29 148 can at least par t i a l ly p rote c t corn p l a n t s f r om t h e
herb i c ida l ac tivit y of t riasu lf uron. Co r n s e e d tr eatment s wi t h
anyo ne of the above safeners wo u l d al low t h e use o f tr i asulf uro n
for weed contro l in co rn cultu re .
LITERA TURE CITED
1. Devl in, R .t-L and 1.1. Zbiec . 1990 . Effect of BAS- 14 5 138
a s an a ntidote for sulfony lurea herb ic id es . Weed Tech .
4 , 337 -340 .
2 . Hat zio s , K.K . 1984 . I n t era c t i on s between se lect ed h e r b i c i d es
an d p r ot e c tant s on corn (~ ~l. We ed Sc L 32 : 51- 58 .

3. Hatz ios , K.K . 19 84. Po t e n t ia l saf e n er s f o r protectin g sor ­
gh um {So rg hum b icolo r (L.) Mo en c h ] a gai ns t ch Lor-au Lf ur-on ,
fluazif op-bu tyl an d s e t .hox yd i.rn, Weed Re s . 2 4 :249-2 54.
4. O'Leary , N.F . and G .N . Prendeville . 1985 . Up t ak e an d phy t o­
toxic i ty of chlorsulfuron in Zea ~ L. in the presence o f
1, 8- n a p ht h alic anhydride. Weed Re s . 25 :331-3 39.
5. Parker , C., W.G. Ri chardson, a nd T ..M. We s t. 1980 . Pot en tia l
for ext e n din g th e se l e ct i v i ty of DPX-4 1 89 by u s e of herbicide
s a f e n e r s . p r o c , Br . Cr op Pr ot. Co n f , Wee d s 1 : 1 5 -21 .
6 . Swee t s e r , P .B. 1985. Sa f e ni ng o f sulf ony lurea herbici d es to
ce r e a l c rops : Mod e o f h e r b ic id e a n t i d o te a c ti on. Pr o e. Br ,
Cr op . Pro t. Conf . We e d s 3 :1147-11 54.

The Effect of Chlo r im uron - ethy l on Cranb err y Fru it Qua l ityl
Robe r t M. Devl in 2
Ir e na I Zbi e c 3
ABSTRACT
The effect of chlori muron-ethyl on the qua li ty a nd
devel opmen t of t he cranb erry (Vaccinium macroca rpon cv "Ea r l y
Black ") fr uit was stud i e d . The influ ence o f the herbicide on
berr y vol ume , acidi t y , so l ub l e s o li d s, a nt hocyan in c o n t e n t , a nd
f la v onol c ont e n t was det e rm i ne d. bo th f o r t he year of treat ment
an d fo r th e year a ft er t r e at ment . Pree me r g e nc e ap p l icatio n o f
chlor i muron-e t hy l a t 1.12 , 2 . 24 , 3. 36, a nd 4 .4 8 kg / ha did not
affect t he qual it y an d develo pme n t o f t he c ranberry fr uit . Berr
i e s a na l y ze d t he y ear a f t e r applic ation sh owed in c r e a s e s in
individu al berry v o l ume a nd dec r e as e s i n a c idity due to
chlor i muron -et hy l a pp l ic ati o ns . Al so inc reases in yield we r e
ob s e rved t he s e c ond year a ft e r a p plicati on.
I NTRODUCTI ON
The su fonylurea herbic i d e ch lor im u ron -e thy l [e t hy l 2 [ [ [[ (4 ­
chloro- 6-methoxy - 2-p r imideoy l ) ami no] car b onyl] ami no] s ul f onyl] be n­
zoi c a c id} is a ve r y e f f i c ie nt postem e r g ence h e rb i ci d e for the
c o n tro l of a numb er of i mpo r t a n t br oadlea f wee d s i n s o yb e a n
(1, 3 ) . Chlorimu r on -et hyl c a n also b e appl i ed preemer gen ce and is
readily absorbe d b y plant roo ts and is transloc a ted thro ughout
the plant (2 l . Differential metabolism between su s c e p t ibl e and
tolera nt plant s pecie s ge nerally d etermine s selectivity (2 ) . The
he r b i c i d a l acti vity of c h lo r i mu r on - e t hy l i s de t e r mi ned by its
abili ty t o bl oc k th e a c t iv i t y of a ce t o l a c ta t e s yn th ase, an en zyme
wh ich is necess a r y for t h e sy n th es is o f t he e s s e n ti a l ami no aci ds
valine , leu ci n e , and i s o l e u c ine (2). Con s e qu ently, protei n
syn thesis i s e ven t u al ly t e r minat ed a nd t he tr e a t e d p l an t die s.
I n n umerou s fi e l d st ud ies on cr anbe rry bogs we have sho wn
t ha t cra nbe r ry is rela ti vely tol erant o f chlorim uron -ethy l and
that pre emergen c e applica tion o f t he herbic ide c ont r o l s a large
Paper No 29 77 . Massachu s e t t s Agricul t ura l Experim e n t Sta t i on ,
Univer si ty of Massach use t t s a t Eas t Wa r e ham. Th is r e s e a rc h
Pro je c t i s suppo r ted f rom Exp e r i ment Statio n pr oject No . 629 .
Pr o fe s sor , Lab ora t o r y o f Expe r i me nta l Biolo gy , Cranberry Ex ­
periment St a t ion , Un iv e rs i ty o f Mass a c hus e tts, East Ware ham ,
MA 0253 8 .
Visiting sci entist , Academy of Agricu lture , Szczecin , Po l a nd .

number of bog weeds (unpublished datal. We feel that chlorimuron-ethyl
would make an excellent preemergence herbicide for
use on cranberry bogs .
The purpose of this study was to determine the effect of
chlorimuron -ethyl on the growth and development of the cranberry
fruit. The effects of the herbicide on cranberry fruit volume ,
acidity . soluble solids, total flavonols, and anthocyanin
development were determined.
METHODS AND MATERIALS
A section of cranberry bog free of weeds and having a
relatively consistent number of uprights over a large area was
~~o:~n a~~~o~~e:~~:~t to ~~~~~i~~2o~~e;~~~, w::c~p~;~~~ ~~p~~~~~~~il
four times and the plots randomized within repl icates. Applica ­
tions were made with a hand held knapsacks sprayer as a fine mist
at the rate of 750 l/ha. At harvest berries were hand scooped
and berry volume determined. A sub -sample was taken from each
plot and frozen for chemical analysis at a later date.
After 30 days the frozen berries were removed from the
freezer and their acidity, soluble solids, an thocyanin c o n t e n t ,
and total flavonols determined. Standard methods for determi ning
acidity and soluble solids were employed. Anthocyanins were
determined according to the methods of Deubert (4) and flavonols
according to the methods of Lee and Francis (5).
To determine if chlorimuron-ethyl had any residual effect
cranberries were again harvested from the above mentioned plots
the following year and their growth and development analyzed as
before . All data were subject to analysis of variance.
RESULTS AND DISCUSSION
Preemergence application of chlorimuron-ethyl a t 1.12, 2 .24 ,
3.36. and 4 .48 kg/ha did not affect the quality and development
of the cranberry fruit. No significant differences could be
found in cranberry volume , acidity, soluble solids . and t o t a l
flavo nols (Table 1).
One of the most important parameters me a s u red i n this study
was the effect of chlorimu ron-ethyl on anthocyan in development by
the cranberry. As the cranberry ripens, relatively large
amounts of anthocyanin pigments are synthesized , imparting to the
mature fruit an attractive red color. As might be expected , a
direct relationship exists between color development in the
cranberry and its commercial value. Thus growers must guard
against herbicides that might retard color development. In this
study no significant differences in anthocyanin content were
found when control berries and berries treated with chlorimuron-

ethyl were compar ed (Tab l e 1 ) .
Table 1 . The effec t of c hl o r i mur on- e th y l (Herb ) on c ranber r y
fruit quality. Acidity is in ml o f 0.1 !! NaOH/lD Dg of berries .
,----- --r- - ------ -- ------ -- - _._- ----_ ._--- ---
Herb Vo l Acidity Sol . Solids Anthocyanin Total Fl av o nol s
{kg/hal Imll Imll 1%1 Img/1 0 0gl {mg/ 10 0g 1
0 1. 3 9 255 4.9 31 20
1.1 2 1.39 2 56 4.9 32 1 9
2.24 1. 3 8 255 4 .9 32 21
3.36 1.38 256 5 .0 2 9 19
4 .48 1. 4 0 257 5.1 28 1 8
----------
SO 5% 0 .13 7 .5 0 .21 4.4 2 .0
'--
1% 0 .18
_ .1-
10.4 0 .29 6. 0 2 . 7
_
A percent drop in yield was o bserved wi th incr easin g rat es
of c hlori muron - eth yl app lied . However , the drop in yie ld was not
s i gn i f i c a n t , on ly sugg e stive of a possible herbicidal e ffec t
(Tab l e 2) . Whe n th e sam e plots were harvested t he fol lo wing
growin g season a significant i nc r e a s e in yie ld was obser ved in
plots pre vious ly t r e a t e d wi th 2.24 , 3.36, and 4 .48 kg/ ha
chlorimuron-ethyl (Tab l e 2). Most l ik el y this was due to be tter
weed c o ntrol where the her bi c ide had been appl i e d.
Tab le 2 . Effect of chlor imuron -e thyl (Her b) on cranb er ry y i el d
in the y ear of app li catio n (lst yr ) and in th e ye ar af t e r appl i­
cation (2nd yr ) ;
Herb Yi e ld 1%1
{kg/ha l 1 st yr 2nd y r
------0- --- -
100
- J:1jQ
1. 1 2 96 11 8
2.2 4 83 134
3.36 79 13 5
4.48 81 134
LSD 5%
-
2 1 31
1% 30 43
In add ition t o differences i n yield , di fferences in v o l ume
and ac i di ty were a l s o obser ved the s e c o nd year. Plo ts prev iousl y
t reat ed wi th 2 .24 , 3 .36, and 4 .48 kg/ha chlori muron -ethyl had
berry volu me i nc r eases of 9 , 12 , and 9%, r e s pe c t i v e l y (Ta b l e 3).

At t hes e s ame r a t e s cranbe rry a c i dity was p ro gre ssively
decre ased (Table 3 ) . I n c o ntr ast, no sign ifi can t dif f er enc es
we r e found the seco nd yea r in th e so l uble s ol i ds , antho cyanin
content , a nd fl avon ol cont en t o f t he c ran be rr ie s (Table 3) .
Table 3. The effe c t o f chl orimu ron -e th yl (Her b ) on c ra nber r y
fruit qual ity t he sec ond y ear a f t e r t r e at ment. Ac id it y i s i n ml
o f O.1~ NaOH/100g o f b e r r i e s .
Herb Vo l Ac id i t y So l.So l id s Antho cyanin Total Flavonols
(kg /hal (mil (mil (%) (mg llO Og) (mg/ l00gl
0 1. 27 32 6 6 . 1 2 8 23
1.12 1.29 3 23 5 . 9 28 24
2 .2 4 1.39 2 91 6 .2 2 6 23
3 .36 1. 4 2 2 88 6 .3 26 22
4.4 8 1.38 275 6 . 2 26 22
LSD 5 % 0. 0 9 1 8 0 . 3 4.0 1. 5
1% 0.12 2 5 0 . 4 5 .6 2 . 1
1_ _ --' _
_.--- - - - -
The da ta in t h i s study suggest th at ch lo r i muro n-et hy l ,
be c ause of it s broad spectrum of we ed co n tro l a nd bec au s e the
cra nberr y i s r elat i vely t ol erant of the herbi ci de , woul d be v er y
us e fu l f or th e control of weeds o n cranberry bogs .
LITERATURE
CIT ED
1. All e n, D.R . a nd P .A. Banks, 1984 . Eva luat i on of DPX- F6 0 2 5
f o r broa dleaf contro l i n soyb ea ns . Pr o c. South. We e d Sci.
So c . 37: 7 3 .
2 . Beyer , E.M . Jr . , M.J . Duffy, J.V. Hay , and D.O . Sch lueter.
19 8 8 . Sul f on ylureas . In P.C. Kearney an d D.D . Kauf man , eds.
He rb i c i de s : C h e m i s t rY~D e g r a d a t i o n , and Mo de of Action , Vol .
3 , pp . 1 17 -18 9. Marce l De kke r, I nc . , New York .
3. Claus , J .S . 1987 . Chlorim uron - ethy1 (Cla s si s) : A new
broadle af poa t emer qe nc e her b i ci de in So yb ean. Weed Tech.
1: 114-11 5.
4 . Deubert , K.H. 19 78 . A ra pi d me t ho d f o r the ext r ac tio n a nd
qua n t i t a t.Lo n of total ant ho c yanin of cranb e r ry fr u i t . J . Ag .
& Food Chern . 26 (6) : 14 52 - 14 5 3 .
5 . Le e s, D. H. a nd F.J . Francis . 197 1 . Quant itat iv e method s for
anthocyanins. 6 . Flavono ls and a n t ho cya n i ns in cra nberries .
J. Food Sci . 36: 1 056 - 106 0 .

10
~ JdlJlSgmass a:.ntrol in Field Qn;n
E. Prostko, J. Meade, and D. Lee l
Orr-farm fi el d tria ls were con:il.rted in 1989-90 to evalua te the
perf ormance of DPX- V9360 and ffiA-136872 on johnsor

11
Tabl e L '!he Effect of DPX-V9360 Q1 Jol'lnsorqrass COntrol in Fi eld Com,
sal em COUnty New Jersey 198 9
Ililt!>
;~~1
Hert?icioi oz AlIA
.DPX-V9360 0 .50 97 78
OPX-V9360 0 . 75 97 78
DPX-V9360 1.00 97 78
lSI) (0.05)
1 Scale 0- 10ot; 0 = ttl oontro l; loo t = carp lete control
2 All treatments i..rcludai X-77 @ o.sa v/V
3 WAT ::; weeks after treatment
11
Table 2 . 'Ihe Effect of DPX-V9 360 arrl aiA -lJ6872 on Johnsongrass control
in Fi el d Chm salem county New Jersey 1990
HerbicW
Ililt!>
oz AI /A
~~'W:f
DPX-V9360 0.25 65 100
0.25 4
DPX-V9360 0.50 79 98
QPX-V9360 0 .50 83 100
0 .50 4
OPX-V9360 1.00 85 100
a;A.-136872 0.29 63 90
0.29 4
mA - 136 872 0. 43 78 97
0 .1 4 4

12
WEED CONTROL I N WHEAT WITH TRIASULFURO N
ABSTRACT
Winte r an nual weeds contin ue t o be a prob lem for produ c ers
atte mpting t o ma ximi z e bo t h yie l d a nd q u a li t y of winter wh e a t
(Triti c um a e st i yium L. ) . Weed s su ch as co rnmon c h i c kwe e d [~
la ria media (L.) vi 11. ) a nd hen bi t (Lamium a mp lex i c a u le L. ) c a n
compe te with the crop and ca use yield r e du ct i o n s whil e wi ld
ga r li c ( Al liu m v i n e a l e L. ) reduces quali ty , t hu s re sult i ng in
lower pr ice s to the produce r. Re search was conduc t ed duri ng t he
ye a r s 198 8 through 1990 to e valuate l ow ra tes (5 -20 g /ha) o f
t riasulfuron applie d in the spri ng for co nt ro l o f th e se weeds
and als o to e va l uate th e po tent i a l fo r carry ove r t o r otati onal
cr op s s uch as soy beans [Gly ci ne max ( L.)Me r r . ] a nd a lf alf a
(~ sati va L.) . Repl i c ated fie ld tr i al s wer e lo c a te d in
Delaw are , Mary land, Mic higan , penns yl vania , and Vi rgin i a. Most
trial s were in whea t while s e v e r a l were conduc ted on heav y
i n f e s ta t i o n s of wild g ar lic g r owi ng in a non -c ro p s i t ua tion .
Wild garl ic c ont r o l from tria sulfuron a t 5 g /h a was 90 - 100 '0 at
mos t l o cat i ons where a wh e a t c rop was prese nt . In no n - cro p
si t ua tio ns, 10 -20 g/ ha were req uire d t o ob tai n ac ce ptab le c o n­
t rol. Cont r o l o f c ommon c h i c kwe e d was ve ry good t o ex ce l l e nt a t
mo s t loca ti ons at rates of 5-1 0 g/ha . Henbit co ntr o l va r i ed from
poo r t o ve r y good depending on l ocati on . Respon se of ro ta tio na l
s oybeans to triasulfuron was v a r i a b l e with no injur y at numer ou s
l o c a t i on s al t h ough soybeans were injured Vi r g i n i a a nd Dela ware .
Al falfa p l a nte d in mi d - to l ate - s ummer was no t affec t e d b y
pre v i ous a ppl ica tio n s o f tr iasu lfuron .
1M. G. Sc h n a p p i n g e r , Senio r Scien tist, Agric . Di v., Ci b a -Gei gy
co r p., centr e vill e , MD 2 16 1 7 , H.P . Wil son, Profe sso r, Ea s t ern
Shor e Ag r ic . Exp . s t n . , Va . Pol y te ch . In s t . a n d Sta te Univ .,
Painter , VA 23 4 2 0, F .J . Webb, Ex te n s i o n Sp e c i a l i s t , We e d
Science, Uni v. o f De lawa re Re s . and Educ. cn t r . , Geo rge town, DE
19 947 , J .D . Abbot t , Field Re sea rc h Rep . , Agr ic. n t v • , Cib a ­
Ge i gy Corp ., La n c a st er , PA 17 6 01, and J . R . Can twe l l , Fi eld
Resear ch Rep. , Agric . Di v . , Ciba - Ge i gy Corp ., Camden , MI. 49232

13
GLYPHOS A1E AND lRICLOP YR APPLIED AS A DIRECIE D SPRA Y OR OVER ·TIlE·TOP
OF CO NIFER S IN TIlE FALL
Larry J. Kuhns l/
ABSTRACf
Glyp hosate and tticlopyr are labelled for use as directed sprays in Chris tmas tree plantings.
Though growe rs are cautioned agains t contacting the foliage of the trees with the spray , it is almost
impos sible to make a thorough band application without conta cting some foliage. Man y growers
have found through experience that COntactingthe lower one-third of Christmas trees after their
leaves and bud s are fully hardened does not harm them. Other growers have sprayed rig ht over the
top of their trees with glyphosate. Some reported injuring their trees and some repo rt they did not.
This stud y was designed to evalua te some of the factors which could affect whether or not an
herbicide applica tion that contacts the foliage of the conifers will cause injury: herbicide and
formul ation, rate of application, species treated, and the amo unt of foliage contact ed.
The experime nt was conducted at the fanns of three cooperati ng grower s and the Penn
State Horticulture Researc h Farm at Rock Springs . The trees at growe rs' farms were esta blished at
least two years and were 30-75 cm tall. The trees at the research farm we re plan ted in the spring
prior to application and varied from 25-40 em tall. At the growers ' farms glyphosate and the amine
and ester form ulations of triclopyr were applied as direc ted sprays to the lower third of the trees or
over the top at 0.3, 0. 8, and 1.6 kg ai/ha. With the excep tion of the amine formul ation , the same
treatment s were app lied at the researc h farm, Several commo nly grow n Christma s tree species,
with varyin g sensitivi ty to glypho sate were included in the stud y. Dou glas fir~
~[(Mirb.)Franco]) was treated at two gro wer sites, while Colorado spruce ~
~[E ngelm .]) , eastern white pin e~ m1?Y.5. L.) , and Scots pine

14
a grower' s site were injured by directed spray and over the top applications of glyphosate at 0.8 or
1.6 kg ailha. Injury symptoms included bud abortion and clustering of new growth rather than the
devel opment of a strong central leader . Glyphosate treated Scots pine at the research fann
appeared to be slightly stunted only by the 1.6 kg ailha rate. Triclopyr treatments did not have any
significant effect on the Scots pine at the reseach farm. At the grower's site some trees with
stunted. clustered growth were scatteredthrough the triclopyr treatments, but they could not be
correlated with any specific treatment, The white pine at the grower's site had some chlorotic.
stunted plants with clustered growth scattered throughout the tes t area.but they could not be
correlated to chemi cal treatment or rate of application. At the research farm the white pine receiving
applications oftriclopyr at 1.6 kg ai/ha over the top or as a direc ted spray, and glypho sate at 1.6 kg
ai/ha over the top. were more yellow and slightly stunted compared to the controls. None of the
Fraser fir at the research farm were injured by any of the treatments.
The extremely dry conditions in late summer, 1987, and all summer, 1988, caused some
stuntingand chlorosis throughout the study areasthat was difficult to distinguish from herbicide
related injury. However, it was evident that the treatments used in this study did not cause severe
injury or plant loss.
Figure 1. Injuryrating of four Christmas tree species planted at the Penn State Horticulture
Research Farm at Rock Springs in April 1987and treated in October, 1987. Injury to
the trees was rated in August, 1988 on a scale of 1-10 with l=no injury and lO=dead.
The herbicides were applied either over the top (0) or directed (0) to hit the lower third
of each side of the trees.
Control
Glyphosate
Triclopyr
LSD (.05)
Injury Rating
Rale Method of Douglas Fraser SCots WhIte
!kuiLb.ill~ IiI IiI lliM ~
1.3 2.3 1.5 2.0
0.3 D 1.0 1.7 1.3 1.3
0 1.7 1.3 1.0 1.0
0.8 D 1.0 1.3 1.3 1.3
0 2.7 2.0 1.7 1.7
1.6 D 1.7 2.7 3.0 2.0
0 3.0 3.0 2.0 3.3
0.3 D 1.7 1.3 1.0 1.3
0 1.0 1.7 1.0 1.0
0.8 D 2.0 . 1.3 1.0 1.7
0 1.3 3.0 1.0 1.3
1.6 D 2.0 2.0 1.7 2.7
0 1.7 2.3 1.7 3.3
2.0 1.5 1.1 1.8

15
CONTROLLING BLACK LOCUST , BOXELDER, AND TREE-OF-HEA YEN WIlli BASAL
BARK APPLIED HERBICIDES
Gregory T. Lyman, Larry J. Kuhns, and Arthur E. Gover t/
ABSTRACT
Basal bark herbicide applications are used to control many types of brush. Variables that
can affect the degree of control provided by a basal bark application include the brush species.
herbicide selected. rate of application , and the carrier. Th is study was designed to investigate each
of these and had the following objectives: 1. to compare the effectiveness of 5% and 20% Garlon
411(tric1opyr) and 5% and 20% of a combination of Accessv (triclopyr + picloram) ; 2. to
compare the effectiveness of diesel fuel and mineral oil as earners; and 3. to compare me
effectiveness of three herbicides-triclopyr, triclopyr + picloram, and irnazapyr.
TIle herb icide treatme nts used are listed in T able L Th e tree speci es trea ted were black
locust

16
Inj ury
Rating
Number of Stems
Chopper)/
6.25%
Diesel
Fuel
boxelder Tl 1"2 T I 1"2 Tl 1"2 T I 1"2 T l 1"2 Tl 1"2 Tl 1"2
Total
I I I I I
39 39 I 34 34 31 31 33 33
1
3
5
6 5
13 8
11 26
39 39
tree-ofheaven
o
1
2
3
4
5
Total
T I 1"2 Tl 1"2
I I
I
6
3 5
4 8 I 3
~ ~ HI ~1 § ~
Tl 1"2 T I 1"2 Tl 1"2 Tl 1"2
I
3 1
5 4 14
34 38 I 40 40 I 17
I
4 4 3
18 I 28 29
Tl 1"2
6
8
5 1
7 I
12 8
4 32
42 42
black locust T ! 1"2 Tl 1"2 Tl 1"2 TI 1"2 Tl 1"2 Tl 1"2 Tl 1"2
I I I
o
I
2
3
4
5 16
19 19 I 9 9
Total 19
20 20 II I I
9
11Garlon 4 is an emu lsifiable conce ntrate containing the acid equivalent of 480 gil triclop yr,
DowEJanco, Indianapolis, IN
2JAccess is an emulsifiable concentrate containing the acid equivalents of 120 gil picloram and 240
gil rriclcpy r, DowE lanco. Indianapo lis, IN.
31Chopper is a water soluble concentrate containing the acid equiva lent of 240 gil imaza pyr ,
American Cyanamid Com pan y, Wa yne, NJ.
4/ Rite Way , N.G. Gilbert Corporatio n, Muncie, IN.

17
COMPARINGTIlE CONTROL BY BARK ABSORBEDHERBICIDES APPLIED AT TWO
HEIGHTS
Gregory T. Lyman , Larry J. Kuhns, and Anhur E. Gove rt /
ABSTRACT
The basal bark technique of herbicide application has proven to be an effective way to
control brush. By applying the herbicide at a height of 1.2 m rather than at the base of the plant the
treatment could be made quicker and easier. The applicator would not need to beconcerned w ith
clearing vegetation from around the base of the stem, brush could be treated even when the base
was co vered with snow. and the bark tissue s at 1.2 m are thinner than at the base. The objective of
this study was to comp are the brush contro l pro vided by triclopyr applied at a heig ht of 1.2 m with
a conventional basal bark:application.
Garlon 4'11(tric lopyr) at 5 and 20% in diesel fuel was applied to stem s of boxelde r maple
CAm~ L.), tree-of -heaven

18
TABLE 1: The numbe r of stems of boxelder maple, tree of heaven, black locust. and black birch
in each injury ratin g category (0-5). A rating of 0 indicates no treatme nt effect, and a rati ng of 5
indicates no visible living tissue. Treatm ents were applied in late Marc h 1988 to eithe r the base of
the plant or 1.2 m abov e the gro und. All treatments were dilu ted in diesel fue l. Control was rated
on October 9, 1989.
G arto n 41/ Garlon 4 Garlon 4 Gar lon 4
Injury 5% 5% 20% 20%
Rating Treatedat Base Treated at 1.2m Treated at Base Treated at 1.2 m
Number of Stems
bcxelder Abov e Trt. Above Below Above Above Below
I
I
0 22 14
I
2
3
4
5 39 I 3 1 9 3 1 I 34 20
TOOl! 39 31 31 31 34 34
tree-of-heaven Above Trt. Above Below Above Above Below
I
I
0 I7 20
I
2
3 5
4 8 4
5 II 32 17 38 I 40 20
Total 24 34 34 42 40 40
black birch A bove Trt. Above Below Above Above Below
I
0
I
2 I
3 5 5
4 9 12 4
5 20 16 3421
I 22 25 29
TOOl! 34 34 34 22 29 29
black locust Above Trt. A bove Below Abov e Above Below
I
0 13 15
I 1 I
2 I
3
4
5 15 19 4 19 16
TOOl! 19 19 19 20 16 16
I
I
1/ Garlon 4 isan emulsifiable coeccnuate conta ining the acid equivale nt of 480 gil triclopyr, DowElanco,
Indianapolis, IN.
2JNo sprouting was evident on black birch, while all other species resprouted below the 1.2 m treatment area.

19
JCllNSCll>GRI\SSRFXXJIIERYFR(X.I SllLFONYLUREI\HE>

20
Potential Herbicide Rat e Reduction Utilizing
Mulch Characteristics and ManagementSmuegtes
Robin R. Bellinder, Russell W. Wallace and Luis E. Lanfr anconi'
ABSTRACI'
Sevenmulcheswereevaluated in 1990lor ease a/managementand weedsuppression in tomatoes
~ esculentum ). The mulches were selected f or differing control pot entials and included:
two winter-killed mulch es. oats (~ H1I1J!1!} and annual ryegrass fl.!2lium~.. three spring
chemically-killed mulches. red clover (Trifolium~ , grain rye~~ , and redfescue
rE:n.1.JJ.m rJJ1zLg);one mechanically-killed mulch . hairy vetch (Ykig l!il!Jl.El); and conventional tillage
(bare ground). Glyphosare (1.1 kg aitha) and glyphosate (/ .1 kg) + 2,4-D (0.84 kg) were appJled to
rye and red clover. respectively. Redfescue was treated with glyphosate (2.2 kg) and later with
paraquat at 0.6 kg. Although annual ryegrass was winter-killed, a glyphosate + 2,4-D treatment was
required to control perennial weeds. Following tranpkm ting, postemergence herbicides were applied
as-needed. Within each mulch, the herbicide programs included: a weedy check (Trt. 1) and
metrlbuun + sethaxydim applied at 0.56 + 0.22 (Trt. 2),0 .28 + 0.22 (Ii1. 3), and 0.19 + 0.17 kg
aitha (I n. 4). At the time of transplanting, mulch control was complete in rye, oats, and annual
ryegrass. Redfescue , red clover and hairy vetch continued to grow despite regulation attempts.
Approximately 3 weeks after transplanting, percent mulch cover ratings averaged across herbicide
treatments were highest in rye (dead) and redf escue (living) at 80%. Oats and annual ryegrass were
lowest with less than 2% cover. Prefer ential deer (~vjrginianuy Jjeeding during the winter
decreased oat biomass. Initial herbicide treatments were applied 10 days aft er transplanting (DAT) to
oats, 20 DAT to annual ryegrass, hairy vetch, and red clover, and 34 DATto rye and redf escue.
Initial memb uzin applications contributed to redf escue, red clover and hairy vetch suppression.
Plots requiring cwoapplications included treatmenlS 2, 3, and 4 in annual ryegrass, and treatments 3
and 4 in red clover (48 - 50 DAn , however. only the lowest rare of metribuzin was used. In mid­
July, percent weed cover was 50% or greater in all weedy check pl ots except rye and red f escue
which were 39 and 17%. respectively. Within individual mulches there were no significant
differences in percent weed cover regardless of herbicide rare. In comparing mulch systems across
herbicide treatments, two levels Of weed control were observed: greater than 95% in bare ground, rye
and red fe scue, and 65 - 85% in red clover, hairy vetch, annual ryegrass and oats. Weed spectra
varied due to differences in mulch establishment and regulation. For example, dandelion (lgrgJgm
~, wild carrot~ mt:Q1i1)and quaccgras~~ were the predominant
weeds in red clover, oats and annual ryegrass, respectively. When comparing untreated mulches,
yields were significantly decreased in red clover, oats, annual ryegrass and bare ground plots when
compared with rye. When averaged across herbicides, yields were lowest in red clover and redf escue
when compared with rye treatments.
'AssOC. Prof , Research Tech., and Grad. Studetu, Dept. of Fruit and Vegetable Science, Cornell
University, Ithaca, NY 14853.

21
CGA-163935 : A Ne w Tu r fq ra s s Growt h Regu lato r .
J. W. Pee k, R. L . Brooks , P. J. po rpigl i a a nd D. B. v i t.o Lo !
ABSTRACT
CGA- 163935 ( e t hy l 4-cyclopro pyl ( h yd ro xy ) me t h y l e n e - 3 , S-di ox o ­
cyc loh ex aneca rboxy lat e) is a p lan t growt h regu l a t o r whi ch decr e ases
th e ra t e o f f o l i a r elo n ga t ion of warm- and coo l-seaso n tur fgrasses.
CGA- 163935 r ed uc e s c e ll e l onga t ion by i nh ib i tin g gib bere l li c a ci d
bi osyn t h e s i s . CGA-163935 ha s p r ov en to be a n e f fective p roduct i n
red uc i ng t he fr e qu e ncy o f mowing an d the a mount of clipp in gs
pro du c e d by the turf . I t can a lso be u s ed t o mi nimi z e t he nee d for
ed gi ng turfgras se s . CGA- 163935 i s very e f f e c t i ve on f a s t - g r owi ng
so u t he r n tu rfg ra ss e s s u c h a s s t. Au gu st ine gra ss ( St en o t aphr um
s ec und a tum IWa l t. 1 Kuntz ) . ba h iag ra s s [Pa s pa Lum no ta tum Fiue gge ),
a nd be r muda g ras s ( Cynodon dactyl on (L .] Pers .) . It is e ff ec tiv e on
coo l s e as on grasses s uc h a s tal l f e s c ue ( Fe s t uc a ar u nd i nace a
Sch reb .) , per en n i a l r ye q r a s s ( Lo l iu m pe ren ne L . ), and Ken t uck y
blueg r a s s ( Poa p ratens is L.) .
CGA-163935 can redu ce mowing s and c lipping s by 40- 50\ fo r f ou r
weeks in highly maintain ed t.u r f q r a s s at rates of 300-400 9 a Ly he .
Higher rates of 600-800 9 e Ly ha can redu ce mowings and c lip p i n gs
for up to eight weeks . CGA-163935 . when applied in a 30 cm ba nd at
the ed ge o f l a wn s, can red uce the extension of turfgrass stol on s
thereb y min imiz ing th e need f o r mechanically e d g i ng the pe rimeters
of a l a wn .
Various f o r mu l a t i ons will b e ava I Le b Le . A 1 l b acti v e
ingredi e nt /gallo n MEC wil l be f o r u se on high ly mai ntained
tu r f qr as s fou nd on golf co u r s e s . sod f arms, an d lawns. A 2 lb
acti ve i n g red ie n t / gall on EC will be f or u s e on l ow ma i nt en a n c e
t u r f q r a s s fo und a lo ng r oa ds id es. parks , a nd c omme r c i al /m un i c i pal
prop e r t y . A more d i l ute f ormu lat i on wil l be us e d by home owne r s t o
dec rea s e- th e ne e d o f e dg i ng along c ur bs . fences , an d f low er bed s.
CGA-16 3935 can be us e d w i th ou t a n ad ju va nt and c a n be ta nk - mi xed
with ot he r commonly u sed tur f pe sti ci de s . App li c a ti on s a r e
rain fa s t wi t hi n one h ou r aft e r application because CGA-1 63935
is f oliarl y absorbed.
lCI BA- GEI GY Corp . , Agric ultural Di vision. P. O. Box 183 00 .
Greensboro , NC 27419 - 8300

22
EFFECf .3fJ?~~li:~.wt1l!~~~IfWo~~QUIN
G. 1. Tuxhorn, D. 1. Shaner, and K. Farny l
ABS1RACf
14e imazaquin and imazethapyrwere used to investigate the effect of
¥H on imidazolinone adsorption to soil, and bioavailability to maize.
a ~d ~?~~vc.s~6iliU;~ci :aI~: S~r~~d~~~:~~ilibtllin ~~ ~~i~~cdid~gi
decreasewithpH as rapidly as expected fromincreasedY" adsorption to soil.
This is attributed to a greaterfcfoportionof the imidazolinone molecules
~b~~r\~d ~~:r ~hned~iiioC~ i~~~~ f~::' at low pH, which is preferentially
1Research Soil Scientist, Associ ate Research Fellow, and Technical
Specialist,American Cyanamid Company, Princeton,NJ

23
UNDERSTAN DING WHO LE PlANT ACTIVI TY OF THE IMIOAZO UN ON ES: RELATIONSHI PS
OF PHYSICQ.C HEMICAL PARAMETE RS TO ROOT ABSOR PTION AN D TRAl\I$ LCCA TION
DL Utt le. D.L Shan er, D.W . Ladnef. 8 . Tecle 1, and A. D. I1nicki 2
ABSTRACT
Herbic idal activity of the imidaz olinones is known to be cor rela ted with phy sical and chemical
param eters. Mode ling the com ponent processes of herbici de actio n. that is absorption,
translocation . metabol ism, and intrinsic act ivity at the site of action. may help us to und erstand
differences between compounds at the whole p1art level. Root absorption of 5'-su bstitut ed
pyridine imidaz ollnones in both cor n and sunflower was highly cor related wit h their lipoph ilicities .
ONP-treated plants absorbed little imidaz olinone , indicating that most of the abso rption is due to
ion trapping and not to part itioning to lipids. Mocleling translocation in corn was complicated by
metabolism. However. in sunflower the model for translocation from roots 10 shoots contained
parameters for Iipoph ilicity and electr onic natu re. Therefore, 5'-subs tituted pyridine
imidazolinones which have lipophilic, elect ronegative subs lituents at the e-pcsucn shou ld be
well transported in p1art s.
1Res. Bioi., Assoc . Res . Fetlrm , Group Leader , and Res . Bioi., respective ly, Amer ican Cyanami d
Co., Agricuttural Resear ch Division, Princeton , NJ 08543.
2p rof., Dept . Crop Science, Rutgers University, New Brunswick, NJ 08903.

24
ACCENT : DUPONT 'S NEW POST EMERGENCE GRASS HERB IC IDE FOR CORN
Jo hn T . Andaloro 1/ an d Donald D . Ga n s k e 1./
ABSTRACT
ACCENT (fo rmer ly kno wn as DPX-V9360) i s a ne w h erbi cid e fo r
posterne r genc e g rass a nd spe c ifi c broad l eaf we e d c ont r o l in fiel d
co r n fr o m Dup ont Ag r ic ul t ura l Pr o du cts . ACCENT i s a memb er o f th e
sulfonylurea class of chemis try i n hibi ts th e b i o s y nthesi s o f
vali ne a nd isoleucine , whic h are nec essa ry for cell divisi on , by
inh i bi t i ng th e e n zyme ace tol ac t a t e synt hase. Th i s e n zyme s yst em i s
s pec i f ic t o plant s s o mammals a r e not a t r i sk. ACCENT ha s a n a c ute
o ra l LDSO of >5 , 0 0 0 mg/ kg a nd i s n ot a s k i n sen si tize r. ACCENT h a s
not s how n any mutag e nic, carci no geni c, nor t er at ogen ic effe c t s in
any of t he completed ac ute a nd c hronic s t udie s . ACCENT has low
t ox i cit i y t o fi sh, dap hnia, bobw h i te , qu a i l , a nd malla r d du cks.
ACCENT is f o r mul at e d as a 75% ac t ive ing red i e nt. Compl e t e
con trol of the l a be l e d weeds is ac hieved 2-4 we ek s a fter
applica tio n a l t hough he rbicidal effec ts a ppear wi thi n a f e w da ys
after t r e a t me nt. Chloros is and s hoo t gro wt h i nh ib it ion ca n be
obse rved 5-7 da ys a f ter a pp l ica t on . Di f f er en ce s i n th e d eg re e of
co nt r o l or se le c tiv i ty are b a s ed on d iffe ren t r a tes of me tabo l is m.
ACCENT has been evalua t ed in over 500 fie ld t ri a l s by Dupont
researchers, university cooperato rs , and i nde pe nde nt con tr ac to rs .
These trials confirm tha t ACCENT has shown excellen t t o l e r a nc e
across a wide number of cor n var ieties thus t h e r e a r e no v a r i e t a l
r e s tri cti ons on t he ACCENT lab e l . ACCENT app led po st emer gence a t
t he use ra te of . 66 02 produc t/acre ( . 5 02 a Lya ) ha s e xc el len t
broad spec trum act -LvLt y on bo th perennial and ann ua l grass es a s
well as on several key broadleaf weeds (Table 1). Pos t e mergence
applica tio ns from th e 2 t o 6 leaf st age an d post di rec ted
a pp l i c atio ns f or 6 t o 10 l e a f c or n a re curr ent l y labele d . Th e u s e
of a crop oil c oncentra te or a non-i oni c s ur fa ctan t i s re quired .
The addition of liquid nitrogen fer tilze r (e .g. 28 -0 -0 , 32 -0 -0) t o
t he spray solution may improve cont rol of ce r tain weed s pecies .
Cr o ps no rma l l y ro ta ted follo win g ACCENT- t re a t ed cor n have not
s hown inj u ry . Th e ACCENT l a be l c urre ntl y r e qui r e s a 10 month
interval f rom application of ACCENT t o rep lanting of so ybea ns ,
whea t, popcorn , swee t corn , barley, dry beans and oat s . A 12 mon th
recropping interval is required f o r alfa l fa .
The ACCENT l a be l pr ohi b its i t s us e a f t e r t h e a pp lica t io n of a ny
form ulation of soil -applied COUNTER, s ince unacce p ta b le co r n i nj ur y
may occur . This i s the r e s u lt of an organophospha te in t era c ti on .
However, the us e of other organophosphate soil i nsec t i cid e s prior
to ACCENT ap pli ca t io n is per mit t e d . In a dd it i on , th e ACCENT la bel
pro hi b i ts a pp l icat io n o f f o liar or ga nop ho s phat e s wi thi n 7 d a ys
before or 3 days af ter ACCENT applic ation.
1/ Develop ment Represen ta tives, Dupo nt Ag ric ultur a l Pr od ucts ,
Bar lev Mi l l Pl aza, P.O. Box 80038, Wil mi ng to n , DE, 19880- 00 38

25
WEEP SPECTRUM CONTROLLED BY ACC ENT AT . 6 6 0 2 P RODUCT I A:CRE
SIZE RANGE
HEIGH T ( INCH ES)
Shatte rca ne
Joh nsongrass
see d ling
rhi zome
Sorghum
Foxtai l s
gi a nt
yellow
br istly
green
Fa ll penf.cum
Bar-nyar-dqr-aas
Broadleaf si gnalgrass
Sa ndbur
Wool ly Cupgrass
Quackg rass
4 -12
4 -1 0
8 -12
4 -1 2
2 -4
2 -4
2 - 4
1 - 4
2 - 4
2 -6
1 -2
2 - 4
2 -4
4 -8
BROADL EAVES
HEI GHT ( INCHE S)
l1or ninglory
i vyleaf
ta ll
pitted
Pi g we e d
smooth
redro o t
Smar tweed , annual
Jimso nweed
2 - 3
1 -2
1 -2
1 -4
1 - 4
1 - 4
1 -3
Op tim um herb ic idal ac t ivity fo r t h i s size range c a n be
a chieved wi t h ACCENT a t . 6 6 02 product per a c r e . Howe v er
weeds whi ch exc eed th e se h e i g ht ranges by 50 % may b e
par tia lly con trolle d wi t h rates betwee n .6 6 and 1. ) 3 02
product per a c r e.

26
Canada Thistle Contro l in Wheat
Mark S. Causey and Frank J. Webb'
ABSTRACf
Field exper iments were conducted in 1989 and 1990 to evaluate clopyralid and
thifensulfuron + tribenuro n for their activity on Canada thistle (Cirsium arvense (L.)
Scop) in wheat (Triti cum aestirium). Cont rol ratings were obta ined only for Canad a
thistle. The wheat crop was planted conventiona lly in a clean seedbed each year. The
plot design was a random complete block with three replications. The experiment was
conducted at a different location each year in New Castle County, Delaware on
Matapeake silt loam soil. Thifensulfuron + tribenuron was tested at rates of 0.23 and
O.281b a.i./A alone and at O.231b a.i./A in tank-mixes with either .38 Ib a.i./A 2,4D
ester or dicamba at .13 Ib a.i.j A. Clopyralid was tested alone at a rate of .33 Ib a.i./ A.
Tre atments which contained thifensulfuron + tribenuro n alone or in combination with
dicamaba or 2.4D ester all provided in excess of 91% control. Clopyralid alone had a
control rating of 91.7% in 1989. In 1990 treatments containing thifensu lfuron +
tribenuron alone or clopyralid alone provided 90 and 93% control respectively. In the
1989 study when thifensulfuron + tribenuro n was tank-mixed with either dicamba or
2,40 ester , no difference in control ratings was experienced, however, in 1990 when
thifensulfuro n + tribenuro n was tanked-mixed with either dicamba or 2,4D ester, control
ratings were significantly lower than when thifensulfuron + tribenuron was applied
alone.
'Extension Associate, Weed Science, University of Delaware
Extension Specialist, Weed Science, University of Delaware

27
EFF ECT IVENESS OF CLOPYRALID FOR THE CONTRO L OF
BROADLEAF WEEDS IN VEGETABL E CROP S
w. P . Cowgill ; J r. an d B . A . Majek '
Abstract . Clopyralid effec tively contro ls many pere nnial and an nual
broad leaf weeds in cludin g Canada t his tle [Cirsiu m~ (L . ) Seop. I . hairy
gali nsoga [ Gali n soga cilia ta ( Raf .) Blake ) . common cock lebu r ( Xan lhi u m
strumarium L .) . and common ra gwee d (Ambrosia arte mismolia L.). The ra te
required to contro l seed ling a nnual wee ds was much lower tha n th e rat e
required to contro l perennial wee ds . Canada thistl e was contro lled b y 0 .3
kg/ha applied pos te merge nce . Annuals, suc h 8 S hair y gali nsoga , were
contro lled by rates as low as 0.05 kg /h a. Pos temergence applicatio ns of
clopyralid to cole crops , onion cro ps, and asparagus ca used no phytoto xic
response and di d not re duce cro p yie ld or quality.
INT RODUCTI ON
Broadleaf wee ds continue to be a significan t p roblem in major vegetable
production areas of th e USA . Cana da thistl e and oth er pere nnials are primaril y
problems in perennial vegetable crops . Annual broad leaf weeds, su ch as hai ry
galinsoga , common cock lebu r , common ragweed , eas tern bla ck nightshade
(Solanu m pty canth um Dun . ) , and others are major prob lems in annua l veg etable
crops .
METHOD
Field exp er iments were conducted in 1987, 1988, an d 1989 on muck soil in
Warren County, and on coars e-tex ture d mineral soils in Cumber land and Salem
Counties , New Jers ey . Clopyrali d , 3, 6-dichl oro -2 -pyri din ecar boxyli c ac id , was
evaluated as a post emerge nce herbicid e in as pa ragus, onions, and sev eral cole
crops at betw een 0.035 an d 0 .84 kg / ha . Cabba ge , b roccoli , cauliflowe r, brusse ls
spro uts , collar ds , kale , mustard gr een s , an d Chin ese ca bbage wer e included in the
cole cro ps evaluate d . All expe ri ments were evalua ted for phyto toxicity, effic acy
and eff ect on yie ld .
RESULTS AND DISCUS SION
Cole cro ps (Tab le 1) and aspara gu s (Tab le 2) wer e not injur ed by
post emer gen ce clopyra lid applica tions of 0.4 2 and 0. 84 kg/h a , resp ec tively .
Onions (Table 2) wer e not injure d by two pos temerg ence applica tions of 0.28 or
0.4 2 k g/h a per applica tio n alone or in combi na tion with met ha zole. Canada
thistle contro l was acc ep ta ble in asp aragu s one year aft er clop yra lid was applied
pastemer gen ce a t 0.28 kg/ ha in Jun e when the weed was 50 cm tal l (Tabl e 3) .
Lower rat es pr ovide d temporary contro l, bu t res ults wer e not sa tisf actor y one
year af ter tr eatmen t. Sen sitive annu al broa dleaf weeds , incl ud ing hairy
galinsoga, common cocklebur , common ra gweed , and eas te r n bla ck ni ght sh ade ,
wer e contro lled by pas temer gence applic ati ons of betwee n 0. 035 a nd 0. 20 kg /ha
1 Agr. Age nt , Hunte rd on Coun ty , Flemin gt on , NJ 08822- 9058 an d Ass oc .
Prof . • Rutgers Univ .• Br idg eton . NJ 08302-9 499

28
Tabl e 1 . Crucif erae crop tolerance and yields following postemergence clopyralid
applicatio n
Clopyra lid (hg l h a)'
Crop 0 .0 1ll 0 .1 0.2 0.3 0. 4 LSD (0.05)
Cabbag e % inj . 0 0 0 8
h g lha 32 ,928 30,240 34, 048 9,532
Caulifl ower % inj. 0 0 0 0 NA
h g lh a 84, 398 51 , 945 50,71 2 80,09 6 25 , 386
Collar ds % inj . 0 0 NA
Brocco li %inj . 0
Brussel s sprouts %inj . 0
Bok Ch oy %inj .
Chin es e cabba ge % inj . 0 10
Mustard % inj. 0
Kale % in j.
DCPA applied at planting
'2 Hand - weed ed control
at 8 kg/ha
Table 2 . Liliaceae cro p tolerance and yield foll owing post emergence clopyralid
appli cation
Clopyra lid ( h gl ha)
Cro p 0.0 ' 0.1 0.2 0.3 0 .4 L SD (0 . 05)
Aspa ra gus %in j . 0 0 0 NA
kg l ha 1, 329 1 , 263 1 , 604 1 , 690 344
Onio n -y ellow" %inj. 0 0 0 0 9
kg lh a 12,80 0 11,4 00 15 , 000 11,400 4 ,000
Onion -t-ed " %in j . 0 0 0 0 10
k g /h a 16,200 13 ,800 15, 600 13, 000 3,8 00
Onion-gr ee n
b u nchi ng" %inj .
Leek" % inj . 25
1 Hand-wee ded control
'2 Dry bul b ; methazole applied post emer ge nce at 0. 55 kg /h a
~ DCPA applied at planting at 8 kg/h a

29
Table 3. Broadleaf weeds controlled by postemergence clopyralid applications
Con tro l Clopyra lid (k g / ha)
Weed ra ti ngs 0 0 .05 0 .1 0.2 0 . 3 LSD ( 0 .05)
Aste r . whit e h eath % 75 8
Cockle bu r. common % 93 100 18
Galinsoga , hairy % 100 100 100 NA
Gold enrod . Canada % 68 16
Lambsqua r -ter , common % 10 0 63 24
Mugwort % 68 13
Nightsha de J eas te rn bl a ck % 100 100 NA
Pigwee d. smooth % 13 20 30 24
Purs lane, common % 0 0 0 7
Ragweed , common % 90 90 33
Shepher dsp ur s e % 0 9
Sma r twee d , Pe nn syl vani a % 15
This tle, Ca nada % 35 85 20
Velvetleaf % 10 7 20 22
(Tab le 3) . Inj ur y was simila r to tho se observe d fo llowing th e ap plica tio n of
2.4 -D . Symp toms includ ed epina sti c respo nses, swelli n g of the growing poi nt ,
and b ri ttl eness followed by d eath of sens it ive weed sp eci es . Smooth pigwe ed
(Amara nt hus hyb ri du s L.). common lamb squart er (C he nopodiu m al bum L. ). common
pur s lane ( Port u laca olerac ea L , ), common chickweed [S tellar ia medi a (L . ) v tu .} ,
and velvetl eaf (Al b utilo n th eophrasti Medik.) were not contro lled b y clopyra lid.
Clopyrali d app lie d pos temer ge nce ca used no in ju r y to s evera l vegeta b le crops .
in cludin g aspa ragus. onio n s . and cole crop s . Canada t histle was con tro lled b y
0.28 kg/ha . Sen siti ve a n nual weed s were controlled by lower rat es of the
he rb ici de. Certain common b roadleaf weeds and gras s weeds are not controlle d ;
th ere fore , clop yrali d shou ld be eval u ate d in combi na tio n wit h other her bi cides t o
increase t h e spect r u m of weed s co n tro lle d.

30
GROWTH RESPONSEOF YOUNG PEACH TREESTO
CQt.l PETI TIONWITH SEVERALGRASSSPECIES
W. V. Welke r' and o. M. Glenn 2
ABSTRACT
The growt h of young peach tre es i s advers ely affecte d by compet ition
f rom weeds and adja cent vegetat i on. The response of young peach tr ees to
t hre e l evel s of cornpeti tion from three grass specie s was studie d for 2
yea rs. Trees were grown i n thre e d i He rent size veget at io n- f ree squares
(1,2 and 3 meters on a side ) within solid stands of t hree d i ffe rent gra ss
species ['Kentu cky 31' tal l fescue (~ arund inace a Schreb.),
or chardgrass (~ Q...!.Qm..!llil L.), and perenn ia l ryegrass (~
~ L. )l . There was a direct rel a ti onsh ip between t he siz e of t he
vegeta t i on- free area and th e growt h of th e peach tr ee f or both the f ir st
and seco nd years of the s tudy. There was no effe ct on growth assoc iated
wi t h grass spec ies during the f irst year . The gra ss species adjacent to
the vege tation-free area had a s ignificant impac t upon growth of t he
peach trees during the second y ear. ' Kent ucky 31' was t he most
compet iti ve grass, f ollowed by orch ard grass , while perennial ry egrass was
t he least compet i t i ve wit h th e peach t rees .
1 Weed Scie ntist , USOA- ARS- Appa l achi an Fru i t Resear ch Stat ion,
Kearneysvi l I e, WV25430.
2 Soil Scientist , USDA- ARS- Appa l achi an Frui t Research Station,
Kearneys vi l i e, WV25430.

31
NEWHERBICIDES FOR THE CONTROL OF
TRIAZIN E-RESISTANT WEEDS IN NO- TI LL CORN
R. L . RITTERlI
ABSTRACT
Tri a z i n e -res i s tan t s moo t h pi gwee d (~~ L.) is D. major weed
pr oblem in t he mid -Atla n t i c , nort he a s t e rn, lind u pper midwest regi ons o f the
Unite d St at e s. Loca l i z ed inf e s t a tions o f t riazi ne-resistant co mmon lambs quarters
( Chenopodium I\l..bYmL. ) a r e star ti ng t o be c ome wi despr ead through th es e r e gions
as well. Yet , t h e s pr e ad of triazine- resista nt g iant f oxtail (~ ~
Herrm. ) has been mi nimal s i n c e its di s c over y in 1984. To d a t e , mana g eme n t
strategies of these weeds in no-tillage co r n (~ ~ L . ) hav e r el i ed up on a
blanket preemer gence herbicide appli c at i on, such as me t ola ch l or. to provide
ea r l y - s ea s on supp re s s ion. For contr ol o f esc aped t riazin e -resistan t broa d l e af
weeds, a postemerge nce application of herbicides such as di camba o r 2.4 -D is
ge ne r a l ly require d . Fo r control of tri azi ne- r esi stan t gi a n t f oxt ail e s ca pe s ,
the only postemergence he r b i c i d e that ha s pr-ov t ded s ome d e g r e e of co ntrol until
recen tly is pa ra quat, a ppl i e d po st-d irected. Over t h e pas t sev er al ye a r s, a
numbe r of ex perime nt a l h e r b i c i de s ha ve be e n eval u ated for a c t i v i ty on those weeds
i n cor n. Th e di scu s s i on , t h oug h, wil l be limit e d to co n trol of triazinere
s i s t a n t smooth pi gwe e d a nd g ia n t foxtail.
For tr i a z ine -r es i s t a n t smoot h pig weed , V-S3482 has provid ed e xce l l e n t
pree mergence activi ty . For postemergence control of this we ed, CGA- 13 6872 , DPX ­
V9360. pyr id a t e, a nd th i f en s ul fu r on have p r ov i d ed good t o excellen t co nt rol .
For tri azine-resistant giant foxt ail . preem e r gen c e a ppl ic at ions of the
microencapsulated fo r mulat ions of alachl or o r EPTC . as well as pr e emer g enc e
applica ti ons of clomazone , have pro v ided good c ont r ol . DPX- V9360 has als o
pro v id ed good to excel lent postem ergence c on t r ol of t hi s a nnu a l grass species.
11 Assoc . Prof., Agr ic. Exp . St n. Ag r on . Dept. , unt v . o f MD,
Coll eg e Pa r k , MD 20 74 2 .

32
ANNUAL WEED CONTROL IN CORN WI TH SULFONYWREA HERBICID ES
Rus se ll
R. Hah n'
ABSTRACT
Fi eld exp e r i men t s we r e con ducted in 1989 an d 1990 t o ev alu ate se veral
su l f ony l u re a h e r b i c i de s and s pray a djuva nt s for a nnua l gr a s s an d b roadl ea f weed
co nt r ol i n fi eld corn (~ ~ L.). CGA·136872 and t hi f en s u lfu ron were
eva l u ated f o r ve lvetleaf (Abut ilon tbeo phrasti Hedik .) and triazi n e-resi s tant
c ommon lambsqu a rt ers (Ch en opodi um~ L.) c ontrol. DPX-V9360, DPX-E9636, and
DPX-79406 were evalua t e d for control of lar ge crabgrass [~ sanguinalis
(L .) Seop. ], fo x t ail ( Se t ari a sp p .). wild mus tard (~ arvensis L.) , and
c ommon r a gweed (~ ar te mis! Ho lia L. ) . The ve l vet l e a f a nd lar ge crab grass
exp e r i ments wer e c ondu cted on a gra vel ly lo am wi t h 4. 0 ' or ganic mat t e r whi l e
cont ro l o f th e ot her species was eva luated on s ilt l oams wi t h 4 .5 % orga n ic
matter. A ran domi ze d comp lete -b lock des i gn wi t h f ou r repl i c ation s was us e d i n
each exp er imen t . He rbi c ide treatments we r e app l i ed in water to 10 by 25 f t pl ots
usi ng 800 15 fl a t spra y ti ps mount e d on a c ompres s ed air bi cycle sprayer
c alibr a t ed to deliver 25 gp a of spr ay so l ut ion .
Vel vet leaf cont ro l wi t h 0.57 cz ai/A of CGA- 13 6872 was si milar to tha t
obta i ne d wi th pos t eme r ge nce applications o f bromoxyni l at 0.38 l b ai / A or d icam b a
at 0 .5 Lb a i/A , a nd be tter than t hat obta ined wit h 0. 06 oz al i A of
t hl f ens ulf u r on . The addit ion of 4 % (v/v) 28% N to the s pray s o lu t ion i mpro ved
v elvetl e af contro l with bo t h s ul f ony lu re a h e r b i c id e s when a no n i on i c surfactant
was used. When app lied with 1% i v/v) c r cp- ot I conce n t r a te , only thifensulfuron
a pp li c a ti on s b en e fited f rom th e addit ion of 28% N. Si mil a r r a t e s of CGA-136872
and th i f ensul fu r on provi ded exce l lent c ontro l of triazine - r es istant co mmon
lamb squarters with few di f ferences among spray a dditive s.
DPX-V9360 an d DPX-E9636 at 0.50 oz ai/A with 1/ 4 % (v/v) of non i onic
sur f actant pro v id ed exce ll en t f ox ta il and wild mus ta rd co ntrol when app l i e d e a r l y
posteme r gence. The control o f t h e s e s pe c ies was similar t o that obtained vt tb
2 l b ai/A cyanazi ne ap pli ed at t he s ame ti me. Howev er , rates o f DPX-V936 0 and
DPX-E9636 up to 1 .0 and 0.75 OZ/ A r e s pe c ti v el y did not control common r agwe ed.
Combination s of 0.50 OZ/A of DPX-V9360 wi t h 0.9 l b ai/A of atra zi ne or 0.25 l b/A
of d icamba p rovided excellent common ragweed control. However. wi l d mus ta rd and
foxtail co nt rol were not as goo d a s when DPX-V9360 was app l ied a lo ne. The
comb i na ti on o f br omoxynil at 0 .25 o r 0 . 38 I b/A wit h 0. 5 oz/ A of DPX· V9 360
i mpr ov e d common ragwe ed cont rol c ompa re d to DPX-V93 60 a l one bu t did not provide
the sam e l evel of con t r ol as cyan a z i ne.
Postemergence application of DPX-V9360 at 0.75 oz/A controlled large
crabgrass as well as 2 Ib/A of cyanazine in 1989 . Control wich DPX- E9636 and
DPX-79406 at 0.75 oz ai/A was better than wic h cy anazine . Application of 2 Ib / A
of cya naz ine , 0 .75 oz/A of DPX·V9360. or 0 .5 oz/A of DPX-E9636 an d DPX- 794 0 6 when
l a r ge c r ab gras s was i n t he c o t y l edo n to fou r -leaf sta ge f ail ed t o pr ovide
acc eptab le cont ro l i n 199 0 . Howeve r, goo d large c r ab gras s co n t r o l was ob t a i ned
wit h t hese r a t e s of t he s u lfonylurea herbicides when a pplied 6 d ay s la t er.
'As scc . Pro f. . Dept . of Soil, Crop and Atmospher ic Sci.. Cornell Vniv. , It haca,
NY 14853

33
ALF ALFA AND OR CHARDGRASS CONTROL IN NO -TILL CORN
N. L . Hartw ig!
ABSTRAcr
Glyphosate, 2,4-0, atrazi ne, simazi ne and dicamba treatme nts were applied in various
combinations to a three year old alfalfa/gras s stand on the Penn State Agrono my Farm starting in
the fall of 1987. The soil was a Murril l Silt Loam (Typi c Hapludult ) with a pH of 7.0. All
treatments were applied with a tractor mounted smal l plot sprayer with 80015 extended range flat
fan nozzles at 187 kPa and 187l1ha of water. A blanket treatment of Bullet? at 4tb ai/A was
applied preemergen ce on 5/4/89. 'Pioneer 3475' com was planted in 4.57 by 6.1 m plots with a
six row no-till plante r in 76 em rows on May 9, 1988 and May 22, 1989 with 110 kg/ha of 10-30­
10 fertilizer in the row . No addi tional nitrogen was app lied in 1988 since com followed alfalfa but
in 1989, 154 kg/ha nitrogen was sidedressed o n June 26. The alfalf a was 25 to 30 em and
orchard grass 15 to 20 em tall and both were green and leafy when fall treatme nts were appl ied in
1987. Early spring atra zine was applied Marc h 29. 1988 when alfalfa was just breaking
dormancy. Al l pre treatme nts were applied May I I, 1988 when both alfalfa and orc hardgrass were
2510 30 cm.
Com growth and yields were drastica lly reduced in 1988 due to the driest grow ing season
in 100 years. Alfalf a con trol was 89% or better for any treatment that con tained 2,4-0 LVE or
dicamba in the form of Marksman- applied in the fall followed by atrazine + simazi ne at 2.92 + I
Ib/A preeme rge nce. There was considerab le alfalfa recovery growth by June 28 wher e Marksman
was used in the fall. Even the add ition of 2,4-0 to the mixture didn't improve alfalfa co ntrol. The
addition of glyphosate controlled 80 to 97% of the grass with little recovery grow th later in the
summer. Atra zine at O.92 1blA in the fall followed by atrazine + simazine at 2 + t ibiA
preemerge nce gave almo st complet e contro l of both alfalfa and grass. This treatment was also one
of highest yielding in the study. Corn stands were not affec ted by any of the treat ments. Com
height and yield were generally significantly great er where fall applied glyphosate + 2,4-D LVE
effective ly controlled both alfalfa and grass .
The only preem ergence trearmems that effectively controlled alfalf a were those that
contained 2,4-0 LVE. Even dicamb a in Mark sman wasn't quite as effec tive as 2,4-0 and where
triazines were used alone the contro l of alfalf a was the worst. Grass contro l was generally not as
good as from fall treatment s contain ing glyph osate but were usually not significa ntly diffe rent from
the fall treat me nts.
The lack of alfalfa and grass co ntrol carri ed ove r into the next growing season. The best
alfalfa and orchar dgrass contro l was obtained from fall treatm ents conta ining 2,4·0 LYE and
glyphosat e followe d by triazines in the spring. Com heights and yields were the grea test for these
treatments for both the first and second years after treatment. Generally com heights and yields
were only significantly red uced by reduced alfalfa and orc bardgras s co ntrol in the dry year of 1988
and in 1989 mo st trea tme nts were not significant from each other.
J Prof. of Weed Sci. , Dept. of Agron om y, The Penn sylvan ia State Univers ity, Universi ty Park,
PA 16802
2 Bullet = alachlo r + atrazi ne@ 2.5 + 1.5 lb ai/gaI
3 Marksma n = K salt of dicamba + atrazine @ 1.1 + 2.2 lb ai/gal

34
INIROD UCTION
The primary "weeds" in this trial were a two year old stand of alfalfa (MedicagQsativa L.
'Sara nac AR') and orc hard grass

35
MATERIALS AND METIi ODS
This trial was conducted at the Agronomy Research Farm at Rock Springs, PA. The soil
was a Murrill silt loam (Typic Hapludult ) containing about 16% sand. 67% silt, 14% clay and
2.5% organic matter. The area was limed to a pH of ?O before seeding the alfalfa and
orchardgrass in 1985.
Co rn 'Pioneer 3475 ' was planted in 76 em rows wit h a 6-row John Deere Max -emerge 0 0 ­
till planter on May 9, 1988. A row fertilize r (1lD kg ha-! of 10-30-10) was applied with the
planter. No additi onal nitrogen was applied since it wa s felt that the killed alfalfa wou ld prov ide all
the nitrogen necessary for normal growth. Since 1988 turned out to have the driest June and July
in 100 years,nitrogen was surely not limiting.
Fall treat me nts were applied October 14, 1987 afte r a hard frost (-2°C) the night before.
The alfalfa was 25 to 30 em and orchard grass 15 to 20 em tall and ro th were green and leafy at the
time.
Early spring atrazine was app lied Marc h 29, 1988 when alfalf a was ju st breaking
dorma ncy . All pre treatments were app lied May 11, 1988 when bo th alfalfa and orcbar dgrass were
25 to 30 em.
In 1989, the whole trial area was treated with a blanket treatment of Bullet> to contro l
annua l weeds withou t providing furt her contro l of alfalfa or orchardgr ass so the contro l of these
species by the initial treatments could be evaluat ed the seco nd year .
All trea tme nts were applied with a tractor mounted smal l plot spraye r with 8001 5 exte nded
range flat fan nozzles at 187 kPa and 1871/ha of wate r.
Out of fear of losing the trial. it was irrigated once with 501 m-2 of water with an overhead
irrigation system in late June 1988.
The alfalfa and orchardgrass yields were determ ined by harvesting all top grow th fro m a
0.5 m 2 area from each plot in Aug ust or Sep tembe r 1988 and 1989. A sub-sa m ple was saved from
random plots for dry weight determination. Corn sta nd and gra in yields were measured for three
of the four middle ro ws of a six row plot 4.6 by 6.7 m in size . ANOV was run on percent co ntro l,
alfalfa and gras s dry matter yields and com stand. height and gra in yields with the SAS statistica l
package as a randomized complete block design with four rep lications.
RESULTS AND DISCUSS ION .
Com growt h and yields were drastica lly reduced in 1988 due to the driest growing season
in 100 years . Subsoi l moisture was availab le since the rainfa ll for the previous five years was
reaso nably normal . If the corn was able to get off to a good start and develop a root system deep
enough to tap into this subsoil mo isture. com yields of 100 bulA were still possib le without
irrigation . With one irrigation of 50 I m- 2 of water in late June, pote ntia l yields wer e probably
increase d to 125 bulA.
Alfa lfa control was 89% or better for any trea tment that contai ned 2,4- D LYE or dicamba in
the form of Marksman applied in the fall when rated two days afte r com planting on Mayl l , 1988
(fab le 1). Th ere was considerable alfal fa reco very grow th by June 28 whe re Marksma n was used
5 Bullet = alachlor + atrazine@ 2.5 + I .5 tb ai/ga l

36
in the fall. Even the addi tion of 2,4·D to the mixtu re didn 't improve alfalfa control. Th e same rate
of 2,4-D app lied with glyp hosa te in the fall did a bett er job of co ntrolling alfalf a except at the
lowe st rate of 0.25 + 0 .5 lb ailA. Also . the additi on of glyphosate con trolled 80 to 97 % of the
gras s with little recovery growth later in the summer . Th e most amazing trea tment was atrazin e at
O.921b1A in the fall followed by atrazin e + simazi ne at 2 + 1 IblA preeme rgence. Although it took
half the summer, both alfalfa and grass was almost com pletely controll ed by fall. This was one of
the highe st yielding treatme nts in the study.
Com stands were not affected by any of the treatments. Com height and yie ld were
generally sig nificantly greater where fall treatm ents (T2 to T4) effectively controll ed both alfalfa
and grass.
The preem ergence treatme nts had not been applied yet on May 11 so there was no co ntrol
from these at this point in time. Atra zine at 2l b/A had been applied o n Marc h 29 which provid ed
up to 18% grass co ntro l but no alfal fa co ntro l. Alfalfa yields later in the summe r indicat ed that the
only preemergence treatments that effectively controlled alfalfa were those that contain ed 2,4-0
LYE . Even dicamba in Marksman wasn't quite as effective as 2,4·0 and where triazi nes were
used alone the co ntro l of al falfa was the worst. Grass contro l was generall y not as good as from
fall treatment s co ntain ing glyp hosate but were usually not significan tly differe nt from the fall
treatment s.
Corn height s and yields were significan tly red uced as a resu lt of excess ive co mpet ition
from alfalfa and grass early in the grow ing season for the spring trea tme nts .
The lack of alfalfa and gras s control carried over into the next growing season as one might
expec t (Table 2). Treatm ents 2 to 4 provided almost total control of alfalfa and orch ardgra ss and
corn hei ght and yield were am on g the highe st in 1989 when mois ture was not a limiting facto r.
Gen erall y alfalfa and orchard grass contro l was good for all treatmen ts and there was seldom
significant 'redu ctions in com growth and yield s. If 1989 had been a little drier, one migh t hav e
expec ted greate r competitio n from the uncontrolled alfalfa and orchardgrass.
In concl usion , the best alfalfa and orc hardgrass co ntro l ca n be ob tain ed from fall treatm ent s
cont aining 2,4-0 LY E and glypho sate followed by triazin es in the spring. Com heigh ts and yie lds
wer e the great est for these trea tment s for both the first and sec ond years afte r treatmen t Ge neral ly
corn heights and yields were only significan tly red uced by reduced alfal fa and orc hardgrass control
in the dry year of 19 88 and in 1989 most treatme nts were not significa nt from each other.
LITERATIJRE CITED
1. Hart wi g, N.L. U npublished Data
2. Hartwig, N .L. 19 86. Orchardgra ss control in no-tillage co m . Proc. Northe astern Weed Sci .
Soc. 40:16-17.

Table 1: Firstyearalfalfaand orchardgrasscontrolresuhs andcorngrowth and yieldfollowing trc,ltmenls appliedfall ]987 and spring 1988.
= 1~~""l~al~l:",a ,~ Yield Contr~rn S~-ield-
Application ' Co = ntro
Com
No. Treatmen, Rate 5/11 6/28 9/2 5/11 9/2 Stand Height Yield
(IbaJ/A) ( %) (lb/A) Ob/A) ( %) (lb/A) (plants/A) (em) (blJA)
1.Glyphosate + 2,4-0 LYE(Fall) + .25 + 0.5 + 89 ab 364 b-e 139 b-e 80 e 21 e 22,579 a 122 ab 89 ab
Atrazine 4L+ Simazine 4L (Pre) 2.92 + 1.0
2. Glyphosate + 2,4-0 LYE (Fall) + 0.5 + 0.5 + 89. 170 cde 116 b-e 95 ab 183 abe 23,595 a 133 a 106 a
Atrazine 4L+ Simazine4L (Pre) 2.92 + 1.0
3. Glyphosate + 2,4-0 LYE (Fall) + 1.0 + 0.5 + 94 a 80 de 58 de 97 a 61 e 23,668 a 142 a 98 a
Atrazine 4L + Simazine4L (Pre) 2.92 + 1.0
4. Atrazine 900F (Fall)+ 0.92 + 50 b 35 e 9 e 86 be 2 e 22,288 a 143 a 106 a
Atrazine 4L + Simazine4L(Pre) 2.0 + 1.0
5. Marksman' (Fall) + 1.4 + 93 a 444 be 255 ab 0 e 486 a 22,143 a 109 be 83 abe
Atrazine 4L + Simazine4L (Pre) 2.0 + 1.0
6.Marksman' + 2,4-0LY E (Fall) + 1.4 + 0.5 + 96a 404bcd 249 abc Oe 133be 21,998 a 103be 60cd
Atrazine4L + Simazine4L (Pre) 2.0 + 1.0
7.A trazine 4L (E. Spr.) + 2 + O e 948 a 341a 3e 127 be 20,110 a 74 de 57 cd
Simazine 900F + Atrazine900 F (Pre) 1.0 + .92
8. Atrazine 4L (E. Spr.) + 2 + 0 e 320 b-e 104 cde 18 d 171 abe 22,869 a 108 be 89 ab
Simazine90DF+ Marksmans (Pre) 1.0 + 1.4
9. Atrazine 4L (E. Spr.) + Sim. 900F + 2 + 1.0+ 0 e 55 e 37 e 18 d 417 ab 20,764 a 103 be 70 be
Marksman' + 2,4-0 LYE (Pre) 1.4 + .5
10. Atrazine 90DF + 2.92 + 0 e 594 b 324 a 0 e 181 abe 20,255 a 70 e 41 de
Simazine 90DF (Pre) 1.0
II. Marksman' + Atrazine 900F + 1.4 + 2.0 + 0 e 239 cde 197 a-d 0 e 137 be 21,344 a 71 e 30 e
Simazine 90DF (Pre) 1.0
12. Marksman' + 2,4-0 LYE+ .1.4+0 .5+ O e 65 de 7500 O e 449ab 19,892 a 94cd 60e d
Atrazine90DF+ Simazine 90DF (Pre) 2.0 + 1.0
a Alfalfa andorchardgrassyieldsforJune 28 and September2 arereported on adrymatterbasis.
b Columnmeans followedbythe same letterarenot significnmlydifferentat the 5%level according to Duncan'sMultiple RangeTest.
C Marksman = K saltof dlcnmba + atrazine@ 1.1+ 2.2 Ib at/gallon.
w
~

Table 2: Second yearalfalfa andorchardgrass control results and com growth andyieldfollowing treatments applied fall 1987 andspring 19&8.
If:llfa Orchardurass
Applicati on Control Yield Control Yield
No. Treatmenta Rate 7(3 8/20 7f3. 8/20 In ~ry Stand Height Yield
(Ib iiiJA) ( % ) (Ib/A) ( % ) (IblA) ( ) (plants/A) (em) (bu/A)
1.Glyphosate + 2,4-0 LYE (Fall) + 0.25 + 0.5 + 59 eb 57 be 99 0 25 b 40 a-d 18,150 a 148 abe 109 ab
Atrazine 4L+ Simazine 4L (Pre) 2.92 + LO
2. Glyphosate + 2,4-0 LYE (Fall)+ 0.5 + 0.5 + 94 ab 16 e 100 0 2 b 20 cd 21,054 a 160 ab 125 a
Atrazine4L + Simazine4 L(Pre) 2.92 + 1.0
3. Glyphosate + 2,4-0 LYE(Fall) + 1.0+ 0.5 + 97 ab 2 e 100 a 2 b 19 cd 21,707 a 158 ab 125 a
Atrazine 4L + Simazine 4L(Pre) 2.92 + LO
4. An-arine90 0 F(Foll) + 0.92 + 100 a I e 100 a 0 b 14 d 21,6350 167 0 133 a
Atrazine 4L+ Simazine 4L (Pre) 2.0 + 1.0
5. Marksman' (Fall) 1.4 + 80 abc 22 e 81 a 441 ab 28 bed 19,747 0 147 a-d 133 a
Atrazine 4L+ Simazine 4L (Pre) 2.0 + LO
6. Marksman' + 2,4-0 LYE (Fall) + 1.4+ 0.5 + 96 ab 8 e 79 a 657 a 24 bed 20,546 0 150 ab 108 ab
Atrazine 4L + Simazine 4L (Pre) 2.0 + LO
7. Atrazlne 4L (E'sp r) + 2.0 + 6 d 115 ab % a 88 ab 48 abe 20,764 a 126 cde 116 a
Simazine 90DF + Atrazine 90DF(Pre) LO+ 0.92
8. An-azine 4L (E.Spr)+ 2.0 + 28 d 106 ab 98 0 144 ab 41 a-d 20,618 a 138 b-e 121 a
Simazine90DF+ Marksman?(Pre) 1.0 + 1.4
9. Atrazine 4L (E.Spr) + Simezine 900F + 2.0 + 1.0 + 74 abc 25 e 80 a 338 ab 35 a-d 20,038 a 150 ab 120 a
Marksman' + 2,4-0 LYE (Pre) 1.4 + 0.5
10. Atrazine900 F + 2.92 + 6 d 112 ab 98 a 25 b 53 ab 19,239 a 124 de 120 a
Simazine900 F (Pre) 1.0
11.Marksman' + Attazine900 F + 1.4+ 2.0 + 4d 162 a 96 a 54 ab 60 a 18,586 0 118e 85
Simazine 900F (Pre) 1.0
12. Marksman' + 2,4-0 LYE + 1.4 + 0.5 + 64 be 19 e 83 a 441 ab 31 a-d 19,965 a 145 a-d 109 ab
Atrazine 90DF+ Simazine90DF(Pre) 2.0 + 1.0
a Treatment timings: Fa ll- 10/14/87, E.Spring - 3/29/88. and Pre~ 5/11/88. A blanket applicationof Bullet at 4.0 Ib ai/acrewasmade5/4/89.
b Columnmeansfollowedby the same letterarenot significantly at the 5%level (P=O.05) according to Duncan's Multiple Range Test.
C Marksman = Ksaltof dicamba + atrazine @ 1.1+ 2.2 Ib ai/gal
w
ce

39
CONTROLOF QUACKGRASSWITH CGA-136872
D. B. Vitolo, M. D. Johnson, G. Gillespie and S. W. PrussI
ABSTRAcr
CGA-136872 is a sulfonylurea herb icide developed by CIBA-GEIGY Corporation
for control of various grass and broadl eaf weeds in com (Ul! ~ L) .
CGA-136872 was evaluated at eleven sites in New York, Pennsylvania, and"
Michigan for quackgrass (~~ [L 1Beauv.) control in com in 1990. The
specific objectiveof these field trialswas to evafuate variousapplicationtimings,
including split and early preplant applications, examine the effects of several adjuvants,
and determine quackgrass populations in test sites treate d with CGA-136872 .
Overall controi of quackgrass with CGA -136872 was excellent. CGA -136872
applied at 40 ~ ai/ ha to 10 to 20 em quackgrass provided 95.5 % control when averaged
across nine trials rated at least 40 daysafter application. Split applications
of CGA-136872 at 20 g ai/ ha early postem ergence followed by 20 g ai/ ha late postemergence
provided 97 % controlwhen averaged across four trials. Earlypreplant
applications of CGA-136872 alone or in combination with atrazine + metolachlor provided
excellent quackgrass control. Tank -ntixes of CGA-136872 with atrazine increased the
speed of quackgrass control when compared with CGA -136872 alone.
The addition of liquid nitrogen (28 % VAN) with either Crop oil, X-77, or Sun-it
and CGA-136872 did not consistently improve quackgrass control compared to the
additives alone. The addition of 9.3 I/ ha of liquid nitrogen increased quackgrass contro l
inone trial but had no effect in a second trial.
Quackgrass culms increased from 91/ m 2 to 527/m 2 over a 120 day period in
untreated corn plots. Quackgrass stands treated wi t~ CGA- 13~ 872 at 40 g ai/ha
early postemergence were reduced from 84 culms/ m to 30/m over the same 120 day
period.
I CIBA-GE IGY Corp. , Agricultural Division, P. O. Box 18300,
Greensboro, NC 24719-8300

40
Postem ergence Grass Control in Field Corn with
Nicosulfuron and Primasu lfuron
Mark S. Causey and Frank J. w ebb'
ABSTRACT
Field experiments were conducted in 1988, 1989 and 1990 to evaluate both
nicosulfuron and primasu lfuron for their activity on~in field corn (ill mm
L ). The experiments were performed on a sandy loam soil at the University of
Delaware's Agricultural Experiment Station near Geo rgetown. Control ratings were
obtained for both broadleaf and grass weed species. The com crop was planted
conventionally in a clean seedbed each year. No preemergence herb icides were applied
for either bro adleaf or grass weeds. The plot design was a random comp lete block Wi~
four replications. Primasulfu ron was tested at rates ofC013, .018, .027 and .036 Ib a.i./ A
and nicosulfuron at rates of .016, .031, .047 and .062 lli1r.r.;A. Crop oil conce ntrate w
used as an adjuvant with nicosulfuron and a 80-20 no n-Ionic surfacta nt was used with
prima sulfuron. All four treatment s of nicosulfuron provided in excess of 94% cont rol of
large crabg rass (Digitaria sanguinalis (L.) Scop) while the four primasulfuron treatments
provided from 3 1.6 to 38.9% cont rol of large crabgrass . Primasulfuron pro vided in
excess 91% control of common ragweed (.8..m.llli1si.a arte mjsjifolja L) at all fou r rates.
The range of cont rol of common ragweed with nicosulfuron was from 34.2 at the low
rate to 52.9% at the higher rate. Nicosulfuron provided 64.6 to 79.6% control of
common lambsquarters (Che nopod ium .al.I2Y..m L ) while all four treat ments of
primasulfuron provided in excess of 80% control. It is concluded that bot h pro ducts are
equa l on shatterca ne, but nicosulfuron is far superior to primasulfuron on large
crabgrass. Primasulfuron does control both common ragweed and common
lambsqua rters bette r tha n nicosulfuron.
'Exte nsion Associate, Weed Science, University of Delaw are
Extension Specialist, Weed Science, University of Delaware

41
IINtUAL GRASS

42
LONG-TERM CONTROL OF QUACKGRASS IN CORN FOLLOWING
POSTEMER GENCE APPLICATIONS OF CGA- 136872 AND DPX- V9360
P. C. Bhowmik and B. M. O'Toole l
ABSTRACT
Controlling quackgrass~~ (L.) Nevski.] in field com is a challenge because of
its perennial growth habit. Currently there are two new postemergence compounds that are
effective in quackgrass control. Experiments were initiated in 1988 to evaluate long-term control
of quackgrass in field com. In one study, three rates (35, 70 and 105 gm ail ha) of DPX -V9360
and three growth stages of quackgrass were examined . In the second study, five rates of DPX·
V9360 (17,35, 70, 105 and 140 gm ai/hal and five rates of CGA-136872 ( 10, 15,20 , 24 , and
30 gm ai/ha) were evaluated at the four- to six-leaf stage of quackgrass. These studies were
continued in 1989 for regrowth study. Both studies were also repeated in 1989 and regrowth
studies were continued in 1990.
Each plot was 2.0 by 4.6 m and treatments were replicated three times in a random ized
complete block design . Com 'Agway 584S' was planted May I I, 1988 and April 27, 1989.
Treatm ents were applied on June 3. 21 and July I, 1988 and on June 2, 19, and 29, 1989,
respectively , when the quackgrass was at the two- to three-leaf, four- to six-leaf, and seven- to
ten-leaf stage. Treatments were applied with a COz-backpack sprayer at a pressure of 152 kPa
in 187 U ha. X~ 77 was added at 0.25% (v/v) to all treatments in all studies. Quackgrass shoot
number/400 em", dry weight, and control were determined at various times in each year.
Quackgrass control was rated in July and August. Regrowth of quackgrass in the second year
from 1988 and 1989 studies was examined by quackgrass shoot counts, shoot fresh weights, and
quackgrass rhizome regrowth after incubation.
In 1988 study , DPX-V9360 applied at the four- to six-leaf stage of quackgrass gave better
quackgrass control (99 %) than the applications made at the one- to three-leaf stage (61%) 5 WAT.
Regrowth study in 1989 demonstrated that, plots which had been treated at the four- to six-leaf
stage showed the greatest long-term quackgrass control (85%) compared to the control (46%)
obtained from the application made at one- to three-leaf and seven- to ten-leaf stage) . Similar
results were noted in 1990 regrowth study.
In the second trial, DPX-V9360 and CGA-136872 at all rates controlled quackgrass
effectively 5 to 10 WAT. Regrowth of quackgrass in 1989 showed better long-term control with
D PX ~ V9360 than with CGA-136872 treatments. Quackgrass control the following May (1990)
was excellent in all treatments . Shoot regrowth and rhizome numbers were greater with CG A~
136872 treatments than with DPX~V9360 treatments . In general, long-term quackgrass control
was better with DPX-V9360 than with CGA-136872 .
I Associate Professor and Research Technician, Department
Unive rsity of Massachusetts, Amherst, MA 01003.
of Plant and Soil Sciences,

43
INfERACI10N BElWEEN POSTEME RGENCE APPLICATIONS OF CGA·I36872 AND
SOIL APPLIED INSECI1CIDES IN CORN
M. D. Johnson. D. B. Vitolo, J. D. Abbott, S:M. Mosele y, S. W. Pruss,
and P. J. Porpiglia
ABSTRACT
Greenhou se and field trials were conducted in 19&&-1990 to evaluate the pote ntial
for soil insecticides to inter act with CGA-136872 to cause com (~ .!lliU'S L ) injury and tn
determineif thisinteraction couldbe favorablymanaged.
A 1988 field test first demonst rated that postemergence applicat ions of CGA·
136872 could interact with terbufos applied at planting to cause unacceptable corn injury
when either product alone was safe. Greenhouse tests showed that only organophosphate
soil insecticides had the potential to interactwith CGA-136872, and those ranked: terbufos
> fonnfos > phorate > chlorpyrifos. Field tests in 1989 and 1990 supported this rank ing,
but showed that CGA- 136872 applied over terbufos was the only combinatio n to result in
unacceptab le levels of corn injury when labeled rates of the insecticides and CGA -136872
were used. This terbuf os x CG A-136872 interaction was observed appro ximately 60% of
the time. Fon ofos and phorate have shown the potential to interact with CGA-136872 in
the field, but typically only at higher than labeled rates or when the CGA-136872 is applied
within 20 days after planting. There has been little evidence of an interaction between
chlnrpyrifos and CGA -136872 in field tests. All com hybrids tested have shown susceptibility
to injury from the intera ction between CGA-136872 and terbuf os.
Inter actions betwee n terbu fos and CGA- 136872 were reduced, but not eliminated ,
by applying CGA-136872 late-post rather than early-post, applying the terb ufos in a ba nd
rather than in-furrow, and by using a controlled release formulation rather than the l SG
formulation of terbufos.
j-ciiiA.GEiGY -o,rp. , Agricultural Division, P. O. Box 18300, Gre ensboro, NC 27419-8300

44
EFFECT OF VIRUS OISEASES ONCORNAS INFLUENCEDBY VARI ETY,
JOHNSONGRASS CONTROL METHOD, ANDINSECTICIDE APPLICATION
E.S . Hagood, L.A. VanLies hout, and C.C . Kenl ey
ABSTRACT
Fie l d exper i ment s were conduct ed t o evalu ate t he effect
of va r i ety, met hod of john song ra s s (S or ghum hal apense (L.) Pers.)
contr o1, a nd ; nsec t i ci de app 1; cat; on on developme nt of Mai ze
Dwar f Mosai c Virus and Maiz e Chlorotic Dwarf Viru s di s ea s es in
field cor n (lea mays (L.). The research was conducte d near
Black sb urg , VA on a Ros s si lt l oam of 2. 0% organi c matter con te nt
and soil pH 5 .9. The experimental des ign was a 3-way (2x5x2 )
f act or i al of corn variety x johnsongra ss cont rol met hod x inse c­
t i ct de app1i cat; on . lev e1s with ; n ea ch fa ct or wer e 1) cor n var i ­
et y: 5$- 565 (vir us s usce ptibl e ) and 5S-84 4 (viru s t ol er ant ), 2)
john songras s control method : OPXV-9360, CGA-136872. 91yphose te ,
mechanic al. and control, and 3) i nsecticid e: methomyl pl us
es fen vale r ate and no insect i ci de . Applica tion r at es fo r
OPXV-9 360 , CGA-1368 72. gl yphos at e, mathcmyl , and esfen va1erate
were .040, .035, 2.00 •. 100. and . 055 kg a f/h a, respe ct iv ely .
App1i cat i ons were made to 8-9 1eaf corn and 30-40 cm j ohns ongrass
using 220 L/ha at a press ur e of 210 kPa wit h 8003 flat fa n tips.
Visu al evalua t i ons of cor n vi gor r educt io n and j ohnsongr ass contro
1 wer e made throughout th e growi ng season .
Significa nt ef fect s of cor n var ie ty and john songrass cont ro l
method on disease severity and corn yi eld were observ ed. In later
evaluations , virus damage was 40 and 13% in sus cepti ble and tol ­
era nt vari et i es, r es pecti ve1y. Vir us expr ess i on was grea te r in
plots where j ohnsongr ass was controlled wit h g1yphosat e (29%)
than in plo ts where johnsongra ss was controll ed via CGA- 136872,
OPXV-9360, or mechanical means (8 , 6, and 3%. respectively).
Virus symptoms were great er for bot h cor n var iet i es wher e j ohnsongr
ass was cont r oll ed t han wher e no johns ongra ss cont r ol was
implemented . These valu es were 56 and 24% for the su sc epti bl e
var iety in plot s receiving johnsongrass cont rol and no contro l,
r es pect iv ely, and 15 and 11%for the tol era nt var i et y i n plot s
r eceivi ng joh nsongr as s contro l and no contro l , res pect iv e ly . Corn
yields were clo sely correlated with diseas e sev erity . and were
reduced by 20-30% in response to severe virus infect i on .
Associate Professor. Graduate Research Assistant, and Agricu l ­
t ural Manager , Virg inia Tech, Blacksburg, VA 24061

45
CORN VARIETAL TOLERANCE TO VIRA L DIS EASE AS INFLUENCED BY
CGA- 1 3 6 8 7 2 APPL IC ATIONS TO JOHNSONGRASS
ABSTRACT
Maize Dwa rf Mos a ic Vi rus (MDMV) and Maize Chloro tic Dwarf
Virus (MCDV) a re ins ect tra ns mitte d viral diseases of joh nso n ­
g rass [Sorghum halape nse ( L.) Pers.] th a t also infect c o r n (~
~ L . ) . Fiel d obs erva tion s h av e sh own that ' s ele c t i v e po st e mer ­
genee contro l of jo hnso ngr ass wit h s u lf ony l ur e a h erbic id e s can
i ncr e a s e t he in cid e nce of t he s e di s e a se s i n co r n . In s e c ts feed
on j ohn so ng ra ss which i s t he pr i ma ry ho st of bo t h MDMV a nd MCDV.
Whe n t h e j ohnsong r as s is c ont r oll e d , the con taminated insect
vec to r s move t o t he secondary host , co rn, a nd transmit the
diseas es dur ing th e nor ma l feed ing p r ocess. The r e s u l t i ng
symptoms (d iscolored and s tu nted corn) can easily be misin te r ­
pe rat ed a s herb i c id e in jur y s i nce the t he i nsec t vec to rs are not
ve ry mob i le a nd in f ec t io n is u sual l y li mit e d to the h e r b i c id e
t r eat ed ar ea.
Many see d corn companies have varie ti es t hat are resistant
t o MDMVa nd MCDV but fie ld testing for t o le r a nc e has been limit ­
ed to t rials whe re corn i s grown i n the presence of actively
growing johnsongr ass . Thus, rese a rch was ini ti a t ed in Maryland ,
Virg i n ia, and We st Vi r g in ia to de t ermi ne i f genetic to l e rance t o
HDMV an d MCDV wou l d be a deq ua te when i nf ecte d j ohn s ongr a s s was
s e lec t i ve ly control led wi t h po stemer g ence app l ic a t io ns of CGA­
13 6872. A t otal of eighte en hy bri ds wer e t e st e d i n fi ve r e pl i­
cat ed f i e l d t r i als.
Average di s ea s e l e ve l s r an ge d f rom very low f or a report ed ­
ly " v iru s r-e a Ls t e nt; " var ie ty t o e xt remely hi g h for a kn own
suscepti ble hyb r id. Four o f the var ieties had excellen t tol er ­
ance a t a l l lo c at i ons whil e seve ral ot he rs displ ayed res ista nce
th at var ie d wi t h l ocati on . Numerous var i e t ies wer e i nte r med i a te
i n t oler an c e t h a t might be a dequa t e un der les s seve r e disease
con d i t ions. The use of viru s t o le rant var i e ties can pr event t he
development MDMVand MCDV in c orn following johnsong rass co n ­
tr o l .
I Se ni or Scie nti st, Agric. Di v ., Ciba -Geig y Corp. , Centrev i lle , MD
216 17 , Corn Br ee de r , FFR Coope ra t iv e, Pr ovi d en c e For ge , VA 23 140 I
Associ a te Pro f e s s or, Va. Pol y t ech . ln st. a n d State. Un iv. ,
Bl acks bur g , VA 2406 1 , Assoc ia te Pr of e s s or , Agronomy Dep t. , Uni v.
of Maryland, Co l l e ge Pa rk , MD 20742, and Exten sion Specialis t ,
West Vi rgin ia Univ ., Morga nt own , WV 26505

46
Potential for Cultivation and/or Band Application for Full Season Weed Control in
Com (Zea mays L.)
Lynn D. Hoffman, Greg W. Roth and Joanne Stellingwerf 'l
Three field experiments were conducted in 1989 and 1990 to evaluate band and broadcast
herbicide applications and cultivation for weed control in conventional and no-till com. In
the 1989 trial, com yields were not different under conventional tillage with either a
broadcast herbicide (5.6 L Bicep2/ha plus 1.13 kglha glyphosate in no-till treatments), a
band herb icide plus cultivatio n, or a singl e cultivatio n. Addi ng a cultivatio n to the
broadcast he rbicid e trea tment also did not imp rove yields . In no- rill treatm ents, yields were
approximately 1250 kglha higher where a broadcast herbicide was used compared to a band
applica tion wi th a cul tivation. Com yields obta ined with a full rate broadcast herbi cide
were more than 2500 kg/he greater compared to a single cultivation in no-till. The
ineffectiveness of band applications and cultivation under no-till was due to increased.
competition from quackgrass (Agropyr on rep ens (L.) Beauv.) and yellow nutsedge
(Cyperus esculentus L. ). The 1990 trials consisted of factorial arrangements of tillage (notill
and conventional). cultivation (none and a single cultivation at V6). full and half
herbicide rates (5.6 and 2.8 L Bicep/ha plus 1.13 kg/ha glyphosate in no-till treatments).
and broadcast and band herbicide placement. The experiment was conducted at two
locations that varied in weed pressure-. one was planted into wheat stubble and had
significant weed pressure from yellow nutsedge, green foxtail (Setaria viridis (L.) Beauv.),
redroot pigweed (Amaran thus retroflexus L.) and dandelion (Taraxacum officina/e) and the
second was planted into soybean stubble that had little weed pressure. Cultivation had no
significant impact on yields in either study. In both studies, a significant tillage by method
interaction indicated no yield difference between banding and broadcast applications under
tilled conditions. but a marked yield advantage to broadcast applications under no-till. This
difference averaged 1250 kg/ha in the low weed pressure study following soybeans and
approximately 1900 kglha in the study following wheal Adding a cultivation to the band
treatment did not overcome the negative effect of banding in no-till in either of the two
studies. In both studies there was no yield advantage to using the higher herbicide rate,
even under no-till conditions. The results of these studies confirm that responses to
cultivation on the well drained Hagerstown soils used in this study are negligable and that
band herbicide applications are most suited for corn production systems that include tillage.
1Senior Research Associate, Assistant Professor,and Research Technician,
Department of Agronomy. Penn State University, University Park, PA 16802
2Bicep is a mixture of 0.40 kg metolachlor and 0.32 kg atrazine per liter.

47
CULTIVATION ANO BA ND APPU CATION OF HERBICIDE IN MAIZE
Jane Mt. Pleasant !
and
Can Bannon"
ConcernU!lerthe potentialenvironmentallmpaetofpesticideusehasrenewedInterest Inmechanical
weedcontrol. Cultivation effectively controls weeds In row crops but three or four cultivations may be
needed for acceptabl e control in the absence of herbicides. Weeds in the row can be particularl y difficu lt
to control wit h cultivatio n alone . A field experi ment was conducted to dete rmine if a rotary hoe and/or band
appllcatlon of herbicide In combination with one cultivatIon would control weeds in corn as well as a
broadcast application of herbicide .
The experiment was established at two sites in New York In 1990: Aurora Research Farm in Cayuga
County and a private farm in Mad ison County. Five treatments were appli ed in a rand omiz ed complete
block desIgn w ith four repllcatlc ns et each site. Treatments we re: 1) broad cast herbicid e; 2) broadcast
herblcide-p1us-cuhlvation; 3) band herbicide-plus-rotary boe-plus-cultlvatlon; 4) rotary hoe-p1us-cultlvation ;
and 5) rotary hoe-plus-reduced rate broadca st herbicide. The broadcast herbicide tr eatment used atrazlne
oIb aI/A) and pendlmethaJin (1.5 Ib ai/A) at Aurora and atrazlne 0 lb/A) and metolachlor (2 Ib aI/A) in
Madison County . Similar rates were applied In a ten-inch band CfIIer the com rrm . The reduced rate
herbicide treatment was applied broad cast at one-third the full rate.
There wer e no differences in com grain yields amo ng treat ments at either site, but weed levels
differed by treatment at both locations. In Madison County the broadcast herbicide treatment had the lowest
weed cove r (3%) and the rotary hoe-p1us-cultivation the highest (15%). At this site brood leaf weeds
dominated aUtreatments except th e rotary hoe-plus-reduced broadca st treatm ent wh ere gra sses comprised
most of th e weed populatio n.
At Aurora. broadcast herbicide had the highest weed cover (31%). Weed cover In th e othe r four
treatments ranged from 8 to 20%. At this site hedg e bindw eed~~ (L ) R. Bt.) and yellow
nutsedge ~~ L ) were common weeds . They we re not controlled by atrazjre plus
pendlmethalln alone but the rotary hoe and/ or cultivatio n reduced their levels in all other treatments.
'Assistant Professor, Departm ent of Soil, Crop and Atmospher ic Scienc es, Corn ell University, Ithaca. NY
14853.
lFleid Crop Agent , Oomell Cooperative Extension . Syracuse, NY 13024.

48
REDUCING ATRAZINE RATES FOR ANNUAL
BROADLEAF \lEEDS I N CORN
Paul J. Stac howski and Russell R. Hahn'
ABSTRACT
Two s t r at eg ies fo r r edu ci n g atr a z in e r a tes we r e evalu at ed at: sev en sit e s
i n 1989 an d 1990 . The fir s t st ra t egy was t o app ly redu ced r a t e s of atra z i ne
postemergence wi th a nd without c rop-of I concentrate (CDC). Si mi lar rates of
atrazine were a lso applied preemergence for c ompariso n. The secon d st rat.egy ·...as
to appl y alternate herbicides postemerg ence alone, and with r e d uc e d rates of
a t r a z i ne. The alt ernate h erbicides were dicamha at 0. 5. pendimet h a lin at 1 . 5,
bromoxynil at 0.25 , bentazon at 0.5 with COC at U (vj v). a nd py r idate at 0 .45
o r 0 .90 Ib a i /A.
Convent io na l til lage was used at a l l sit e s . Pr e eme rg ence treatm en t s we re
a pplied on the day of pla n t in g or with in 3 da ys a fte r plantin g. Postem ergence
tr eatments were ap plie d when c orn (~ ~ L .) had four t r ue l e av e s . Spra y
solutions were applied with a CO 2
b a ck pack s prayer deli verin g 20 gpa a t 30 ps i .
The exp erimental des ign was a randomized co mplete b l ock des i gn wit h four
replic a tions. Cont rol dat a was collected fo r common lambs quarte r s (Chenopod ium
a l bum L.) , redroo t pigwe ed (Amar anthus retrofl exus L.). s moot h pigweed
(Ama r an t hus hybridus L. ), wild mustard (Sinapsis arvensis L . ) . c ommon ragw eed
(Amb r os i a artemi s Ufolia L.), and velvetleaf (~ theoph r a sti Medi k .).
Triazin e-resistant biotypes of common l amb s quar t er s and s moot h pi gwe ed were
presen t at some sit e s . Weed control ratings we r e tra ns f ormed to the a rcsine and
sub ject ed t o ana lysis of variance . Two sets of ort hog on a l co nt r a s t s were made .
One set to e xe n dne t he atraz i ne ti mi ng a nd rate main effects and their
i nteractions . The second set t o de t e r mi ne d i f f e r enc es a mong th e a lte r nate
herbi cid es a nd how t he addition of atrazine affec t e d weed con t r o l. The
i nter a c t ions of al ternate herbic ides and the add itio n of at raz in e were also
a na ly ze d .
Dicamba was th e onl y alternate herbic ide that gave good co ntrol of the
triazine -resista nt smooth pigweed . All the altern a te herb i cides gave good
control of th e tri azine-res is tant common l ambs quar t e r s. Atraz i ne a t 0 .5 l b/ A
po stemerge nc e with CDC pe r f orme d a s well as 1.0 or 1.5 lb / A pr e emergen c e f or a ll
s pe c ies exce p t f or wi l d mus t a r d and vel vet l e af. Atr a zin e appl i e d pr e eme r gen c e
at 0 .5 I b/A gave excellent wild mus t a r d contr ol bu t 1. 0 Ib / A of at r a z i ne wit h CDC
was re quired pos t e me r ge nce for excel lent cont r ol. Ve l ve tl e a f was no t a de qua t e ly
co nt ro lle d by preem ergence atra zine applicat ion s up t o 1. 5 Ib/A a nd 1. 0 Ib/A wi th
COC was req u i r e d po s t emergenc e for adequa te contr ol. An a lte rnate he r bicide with
a tr a zln e at 0. 5 l b/ A controll ed each of the weed species as ....el l as . or bet te r
than 1. 5 lb /A of a trazine preemergen c e. Add i ng atrazine a t 0 .5 Ib/A to the
a l t e rnat e he rbicid e s impr oved t h e le vel and s pec t r um of control.
'Grad. Student, Pla nt Pro tec tion and Assoc. Prof., De pt . of Soil . Cr op a nd
Atmos ph eri c Sci . , Cornell Un iv. , Ithaca . NY 14 853

49
REDUCED HERBICIDES RATES IN CORN'
A.J. ENACHE , R. O. ILNICKI and H . WATERS z
ABSTRACT
wit hi n t he gen er al concep t o f sus tainab le agr ic ul ture, th e
use of reduce d h er b i ci d e r at e s may be a solu tion t o j.cv e r-. t he
impac t he r b i c i de s have on product ion c os t s and on env i r onmental
pol lu tion . Se vera l standa rd herbicides were e valu ated in c or n ( Zea
!!@.Y§ L.) at the Adelphia Research Cent er , Free hold, Ne w Jer sey i n
1990 . The object i ve of this stud y was t o de t e rm in e wh e t h e r r educe d
herbicide rates can pro vid e sa tisfac to ry weed c on t r o l as the weed
contro l of the full rate .
The s tudy co ns isted of t hr e e rep licates in a r a nd omi z e d b lock
des ig n . Fo u r r ows of cor n v ar. 'Mid st a t e s 74 7' we r e pla nt e d May 24
i n a Sa s safras lo a m so il wi th pH 6 .3 and 1.9% organic matter. Plot
size was 3 .6 by 5.7 m. Treatments i nc l ud e d appli cations o f 0 .25x ,
0. 5x, 0 .75X , a nd 1x r ates (lx "" recommended full r ate) of premixes
of me t ol a c h l o r , al ach lor, cy anaz ine, and pe ndi meth ali n wi t h
a t ra z i ne , and me t o la c h lo r follo wed by eit he r 2, 4 0 ami ne or di c amba
+ atrazine pre mixes . He r b i c i d es we r e a pp l i e d pree mergenc e (PE),
del a y ed p re emerge nce (OPE) , a nd postemergen ce (PO) on May 25, June
7, a nd June 18 , resp e cti vel y . The mos t pr e va le nt weeds on th e site
included redroo t pig we ed (Amaranthlls re t r o f le xus L .) , common
lambsqua r ters (Chenopodium 9.lmdmL.) , i v yl e a f morni ngg lory (~
~ L. Ja c q. ), a nd fal l pan icurn (pa n i c urn d ic hotorniflo r um
Michx. ) . Weed co nt rol rati ngs were made JU ly 16, 1990 .
We observed that 0. 75x rate (PE) o f me t o lac hlo r + a t r a z i ne
pro vi d e d similar contr ol to the full r ate ( IX) f or all we eds
ev aluated . Alac h l o r + a t r a z i ne at 0. 25x ( PE) fo l l owe d by 0 .25X
(OPE) result e d i n th e s ame co ntrol a s Lx (PE) . Good weed c ontr ol
was obtain ed with O. 25x alo ne e xc ept for fall pan I c um. No
diff erences in we e d c on trol of Lx and se qu e nt i a l a pp l i ca tions o f
O. 25 x (PE) f ollowed by 0.25 x (OPE) o f c ya na z i ne + a't r -azLne or
pend imet halin + atrazine resulted . Th e s ame pattern was e vid ent
with met ol a c hl or (0 . 25x PE + o. 25x OPE) f o l l owe d by 2 ,4 0 ami ne
(PO) . The 0 .5x meto iachior fo l lowed by dic amba + a t razine showed
t he same potential to control weeds as th e full rate of
me to l a c h l or .
This pr eli min ary s tu dy in dica ted th at the O. 5x rat e of mo s t
of t he herbic ides e valua ted p ro vided t he s a me de gree o f we e d
c ont r ol as th e ful l rate .
1 New J e r s e y Agric. Exp . Stn . PUbl icatio n No . J-15472 - 1-90 .
a Res . ASSOC. , Res. Prof. Weed sci ., and Grad . s t ud e nt ,
res pectively, crop s c i. Dept . , Rutgers Univ . , New Jerse y.

50
Influence of Tillage and Prior Year Weed Control on Herb icide Efficacy
in Com (Zea mays L.)
Greg W. Roth, Joanne Stelli ngwerf and Lynn D. Hoffman ]
Four field experiments were conducted to determine the influence of prior weed control
levels on the effi cacy of comb inations of atrazine and meto lachlo r app lied at various rate s.
In twO studies. 0,7 5 and 100% weed control levels wert established in 1989 using
nonselectiv e herbicides. 10 1990. tillage treatments were imposed across the weed control
levels. The tillage subplots were further divided into subplots that recieved four rates of
Bicep2 applied preemerge nce at 0, 2.1, 3.2 and 4.21.1ha. No-till treatments als o reci eved
gramoxo ne at 0.5 1 kglha. Broadleaf and grass weed control ratings and pop ulation data
were collected at four and eight weeks after planting. Corn yields and moisture contents
were determined at harvest Results of these experiment s indicated that both tillage and
prior years weed control interact to determine the herbicide rate where acceptable control
and optimum yields occur. Where tillage and 100% weed control were imposed together
optimum yields were achieved at both locations with the 2.1 l..JhaBicep rate. Where no
control was applied in the previous year, the tilled plots reached max imum yields at the 3.2
Llha rate. Similar response s occured in the no-till treatments, except that yields reached a
maximum at the 4.2 L/ha rate in the plots that had good control in the previ ous year. Where
there was no control, the maximum rate of 4.2 L/ha used in the study was not enough to
achieve maximum yields. Responses to the herbicide treatments were generally greater at
the Landisville site, where the soil weed seed population was about ]0 times greater than at
the Rock Springs location. These results confirm recommend ations that higher rates of
herbicide are needed under no-till conditions and that both weed con trol in the previous
year and soil weed seed popu lation affect the need for herbicides. Response data from two
additional on-farm studies suppo rted these resul ts. No weed control or yield response to
increasing rates of metolach lor from 0.825 kg/ha to 3.3 kg/ha applied with 1.1 kglha
atrazine preemergence was measured in a no-till field with a history of excellent weed
control. In another no-till com field with a history of serious fall panicum (Panicum
dichotomiflorum Michx.) infestations, adequa te control was achieved with only a
combination of tillage and at least ],65 kglha metolachlor in comb ination with 1.1 kglha
atrazine. Overall, these studies suggest that consideration of anticipated weed pressure and
the use of tillage can both contribute to lower herbicide use and improved profitabliry.
lAssistant Professor, Research Technician, and Senior Research Associate, Department of
Agronomy, Penn State University, University Park. PA 16802

51
STUD IES ON THE GERMINATION
REQUIRE MENTS OF NODD ING BEGGARTI CKS
~~L. )
Diane L. Benoit'
Nodding begga rticks~~L. ) is an important weed in carr ot fields in organ ic
soils of Quebec . Field eme rgence studies indicated that this species had a short eme rgence pe riod
in early spring (from the last week in April to the third week of May). The purpo se of this
experiment was to characterize the germi nation requirements of noddin g begganicks . A factorial
experiment with four repetitio ns was set up in 1988 where the factor s under investigation were
nine germination temperatures (5. 10, 15, 20, 30"C constant, 20-5 °. 25 . 10°. 30- 15°C alternating),
two solutions (absence or presence of KNO l
) and intact vs nicked seeds of differe nt ages ( 1984
to 1988). Although all seeds were still viable, none germinated at SOor 1000Cregardless of the
treatments. The presence of KNO) did not influence the germinatio n of nodd ing beggarticks ,
Nicked seeds, where the enve lop around the embryo was da maged , germina ted faster than nicked
seeds where the embryo was undamaged. Intact seeds did not germin ate eventhoug h they were
viable regard less of their age . Alternating temperatures stimulated germination of intact seeds.
Thus, it seems probable that seeds which have overwintered on the soil surface as well as seedbed
preparations earl y in the spring may damage the seed coats of nodd ing begganicks and stimulate
their germination resulting in large seedli ng populations in the spring.

52
SURVEY OF NOXI OUS THI STLE S PECI ES I N SELECTED COUNTI ES IN MARYLAND
Phil i p w. Ti p pi n g !
A BST RAC T
A s u rvey of t h r ee Ce nt r al Mar y l a n d c ount ie s to d eter mine the
a ve r ag e den si ty a nd r e l a t i v e a bu nd a n c e o f fou r n o xiou s th istl e
s pecies wa s co nducted in 1 9 8 9. Th e area s u rveyed i n c l u d e d
Washin g ton, Fr ed eri ck , and Car r o l l Co u n t ies , whi c h co mp ris e
h i s t or i call y the r e g i o n most af fec t ed b y i ntro duc e d t h is t le sp ec i es
in the genera Carduus and £in.i.wn .
The f our th i stle s p ec i es th at we re re c orded wer e musk thistle
(~ t h o e r mer i Weinm.) . pl ume l e s s t hi stle (~ a can th a i d es
L . I, Cana da thistle {Cirsium a rve n se f L . ) Seop .] I a n d b u ll thi s tle
(C irsi um~ t Sav i I t'enc e e.l . Five types of site we re s ampl e d
(li s ted i n p rio r ity ) : pastu res , fie lds , wa ste ar ea s, rig h ts - o f- way ,
a nd ot he r sites ,s uch a s o rc h a rd s . A t ot a l of 1 4 88 s ites wer e
visited with 20 m; samples taken at eac h s i t e.
In Was hi n g t on c o un t s.., t he mo s t we ste r n co u nty , p l u me l e s s
t h istle was t he p r ed o min ate sp ecie s i n p as tu r es an d fields . Mu sk
thist le, l on g co nsidered to be the major p ro b lem spe cie s h ere , was
fou nd at de nsities about 1110 those of plumeless . Ca na da th i s t le
was t he least frequently detected of a l l spec ies , f ou n d at on l y 10
% of s ites . Bu ll t h ist l e , wh i le de t ec t e d with in c r e as ing frequen c y
from west to east in the su rvey a rea , wa s ne v er fou nd at ve ry h i g h
dens i ties.
In F r e d e r ic k Co u n ty, the mos t ce n t ral co u nt y , t he av era ge
de nsit ies of mu s k an d p l umeles s we re low e r, bu t ap p rox i mat e ly the
same for each species in pastures and fields . Howeve r, de n si ties
of Canada thistle increased r elative to more weste r n Wa shin gt on
Co un ty at mo s t si te t y pes . I n th is co u n ty Ca na d a thi st l e we s
d etected as ofte n a s plume less t h ist l e .
Carroll County contained the le ast amou nt of plumel ess an d
mus k th i st l e of th e su r v e y are a, but Cana da t histle wa s f oun d mo s t
f requ e nt ly i n t h is mo s t ea ste r n c o un t y.
This survey indicate s t h a t musk t histle i s n o t as seve re a
proble m a s plu meless th i s t l e i n Centra l Ma r ylan d . T hi s may b e
ev id e nce o f the r egio na l eff e cti ven e s s o f f ede r a l and s tat e
biological control efforts to red uce the populatio n o f mu sk
thistle. Two beetles, Rhinocv llus ~ Froel . • and
Tr i c h o s er o c:a l u s ~ ( Panz er) , a r e n o w well estab li s he d i n t h e
s u r v ey a rea . Bot h sp ec i es p re fer mu sk to p l u me l e s s t hi stl e ,
il lustrating the need for new b i o l o g i c a l age n ts whi c h
prefere n tially attack plumeless thistle. This surv ey a l so no t ed
re lat ive ly h i g h pop ulations o f Cana da t h i s tl e i n ce rtai n ar eas
whi ch may c o nf i r m an e c dot a l e v i de nce th at Ca na da th i s t l e i s
b e c omin g an in c r e a s i n g p r obl em i n Mary la nd .
' -'; n-;o -;;o-l-o-g-i-s-t- ,- -M-a-r-;l -a-n-d- -nePt. of Agric . , An napol i s, MD 2 140 1

53
AES'IRAcr
BJndlben:y

54
INFL UE NCE OF THE HERBIC IDE SAFENER CGA- 154281 ON GLUT AT HIONE
AN D GLU TAT HIONE- S-T RANS FERA SE IN CORN
C. K. Cott ingha m1 and K. K. Ha tzios 2
ABSTR ACT
Detoxication of chloroacetan ilide herbicid es occurs primarily by conjugat ion of the
herbicide with red uced gluta thione catalyzed by glutathione-Sctransferase (G ST) .
Herbi cide safeners are be lieved to confe r protec tion to crop plants by increasing GST
activity andlo r glutathione levels. T his study was design ed to determin e the effect s of the
safene r CGA-1542 81 [4-(dichloroacetyl)-3 ,4-dihydro-3 -me thyl-2H-l ,4-benw xazine Jon
these factors in corn varieties which display differential tole rance to the herbi cide
metolachlor .
In a green house experimen t CGA- 154281 when for mulated with meto lach lcr
(CGA -180937) wasshown [Q be effect ive in safening corn aga inst meto lachlor.
Glu tathione levels were somewhat ele vated relati ve to contro l levels in com treat ed with
metolachlor alone but were not affec ted when the safener was pr esen t. No diffe rences in
glutathione levels were obs erved betwee n the metclac hlor tole rant variety, 'Cargill 7567'
and the metolachlor sensitive variety, 'Northrup-King 9283'. Th e effects of CGA-15 4281
conce ntrati on on GST activity were tested in laboratory expe riments ut ilizing a liquid
culture method. For both corn hybrids treatment with 1 pM CGA- 15428 1 resulted in a
30% stimulation of GST activity. A differe ntial response to safene r concen tration was
observe d for the two corn varieties . Some inhibit ion of GST activity was observed for
'Cargill 7567' at highe r doses of CGA -154281 while neither add itional en hancem ent nor
inhibition was observed for 'North rup-King 9283'. In metabolism studies with excised
apical sections of corn seedlings imbibed with 1pM CGA -154281 a similar enhanceme nt
of rnetclachlor conjugat ion was observed without an incre ase in glutath ione content.
Induction of GST activity was increased to twice that of controls by imbibing seed s with
CGA- 180937.
Th is study suppo rts the hypot hesis that the herbicide safener CGA-15 4281 acts by
enhanci ng GST activity and metolachlo r me tabo lism in corn. It does not however indicate
a direct effect of this safener on the glutathi one status of treated corn plants. Th at GST
activity was most affect ed by the combination of herbicid e and safener suggests the
part icipation of both phytochem icals in the induction mechan ism.
IGr adu ate Research Asst. and 2Prof. ,Dep!. of Plant Path ology, Physiology, and Weed
Science , Virg inia Polytechnic and State University, Blacksbu rg, VA 24061

55
EFFECT OF TEM PERATURE AND SAFENERS ON GLUTATHI ONE
LEVE LS AND GLUTATHION E S-TRANSFERASE ACTIV ITY IN CORN
D.L. Kunk el, J.e.Steff ens and R.R . Bel linder!
ABSTRACT
Studies were conducted to determine the biochemical aspects of chloroacet anilide injury to
com and the mechanism by whic h safeners maintain herbicide tolerance, eve n at reduced
temperatures. Th e objectives of these studies were threefold: one, determin e if glutath ione
(OSH) contentvariedin corn plants grown at three different temperature s in safener -treated
and non-treated plants ; two. determine wheth er glutathion e S-transfe rase (OST) activ ity
varied in plants grown at different temperatures ; and three , determi ne whether GST activity is
sensitive to low temperatures in vitro. The herbi cide safener s CGA-1542 81 [4­
(dichloroacetyJ)-3 .4-dihydro -3-methyl -2H-l .4-benzoxazin e] and dichlormid [2.2-di chloro ­
N, N- di-2-propeny lacetam ide] were used with the herbicides metolach lor [2--ehloro-N-(2­
ethyl-6-m ethylpheny l)-n-(2-methoxy -l -methyl)acetamide] or ecetochlo r L2-chloro-N­
(ethoxymethy l)-N-2-ethy l~6 ·methylphenyl)ace tamide], respective ly, to determin e the
mechani sms of com toleran ce. CGA-15428 1 significantly increased GSH levels in com
seedlings grown at 27° C compared to ncn- safened seedlings. How ever, significant
differences were not seen at 17 or 37° C. Dichlonnid increased aS H levels at all growing
temperatures. Both CGA-15428 1 and dichlonni d increased GST activ ity significantly at all
growth temperatures. The safener-induced GST activity was maintained at in vitro
incubation temperatures of 5 and 15° C for acetochlor and metolachlor respectively. In
contrast. GST activity from non-safened tissue was essentiall y absent at these tempera tures.
There fore, greater a ST activity following safener treatment may result in higher levels of
herbicide metaboli sm even at low temperatures.
1 Grad. Res. Asst., Ass t. Pro f., and Assoc. Prof., Department of Fruit and Vege table
Science, Corne ll University , Ithaca, New York 14853

56
LIFE FORMS AND XYLEM WATER POTENTIAL
OF 94 TAXA AT HEMPSTEAD PLAINS, NEW YORK
Ric hard S talte r. ~"""" Dwig ht T. lGncaid, ~"""" and Eri c E. Lamo nt~ """"
ABSTRACT
T he flo ra of Hempstead Plains . Long Island . New Yor k, was samp le d from
Ap r il 15, 1986 to Oct ober 15, 1986 with 171 vascular p lan ts i d entifi ed . The s e taxa
were ar range d in a Rau n kiaer life form sp ectrum . Hemicrypto phyt es a re th e most
ab undant ( 38%), wi th chamaephytes t he least ab u ndan t ( 2%) lif e form cat egory.
Xylem wate r pot e ntial for 94 taxa was measured usin g a press u re chamb e r on 12
middays from May 1986 throu gh May 1987 for a t otal of 1202 stems . The frequency
distributi on of water potential was highly s tatistically significant fo r pos itive
skewness and fo r leptokurto sis . Gen erally , there is a wide ran ge of xyle m water
pote ntial fo r each life form category during each season of the year . Scar let oak
(Quercus cocc inea) , a phane r ophyte and de wberry (R ubu s flagellari s) , a
chama ep h yt e , d evel op ed water p ot en tials in winter as low as - 45 b ars and -58 .5
bars, respectively . Cryptophyte s and hemicryptophytes had an extre mely wide
ra n ge of wat er potential during spring drough t ( -40.5 t o -0.1 b ars ).
INT RODUCTION
Hemp s t ea d Plains , once en comp as sin g app roximate ly 24,3 00 ha , is loca t ed on
Long Isla nd, New York, USA (40 deg. 44 min. N , 73 deg. 37 min . W) . On e
po r ti on of the ori ginal plains bordering an abandon ed runway on the southern
po r tio n of Mit ch ell Field, approximat ely a ha in siz e , is the least disturbed a rea
of plain s ve geta tion . Th e ve getati on of this a ha tract was s tu di ed by Stal t er &.
Lamont ::o.. ~ who identified 171 vascular plant s during the 1986 gro win g season .
This study reports on th e wat er relations of life forms pre sen t in t he 8 ha
t ra ct at Hempstea d Plain s (Mitc he ll Field ) . Our obj e cti v es were t o de termine t h e
ranges of midday xyl em water p ot en tial and to t est for homoge ne ity among mean
water po t en ti al fo r 94 tax a from five life form categories ov er all seas ons of the
ye ar _ These 94 sp ecies are t he most common plants, an d they comprise about 55%
of the 171 tax a id e ntif ie d b y Stal t er and "Lamont. ::0.. -. Generally , we know little
ab ou t t h e compa rati v e wa te r re lation s amon g a la r ge number of p lan ts in a disc rete
co mmuni t y = - ::0...2 . More over, we k no w of fe w st udies d ealing with th e water
re la ti ons of life form ca te g or ies >Eo .
Rau nkia er ": = classified pla nt s into fi ve major life fo rms bas ed on t h e
pos iti on of th e p erenna ting bud whic h enab les th e plant t o survive d uring
u nfavorable se aso n s " These major catego ries of lif e for ms are phanerophyt es,
chama ep h yt es, he micryp to phytes , cryp t op hytes , an d the ro ph yt es . Pha n ero p hyt e s
are woody plant s with buds ove r 250 mm above th e ground . Woody vines , tall
shrubs , and t r ees fit within this cat e gory . Chama ephyt es ha ve buds exposed
abo v e th e gro u nd
.=:. St. John'a Uni v ers ity, J amai ca, NY 11439, U .S .A .
~ Depart ment of Biologi cal Scien ces. Le hman College. City University of New
Yor k , Bronx, NY 10468 , U .S.A .
~"/ New York Bo ta nical Gard en, Bronx , NY 10458, U .S.A.

57
bu t bel ow 250 nun ab ove t he groun d. Low s hrubs an d cus hi on p lan t s are in cluded
within thi s ca tegory . Hemicrypto p hyt es have th eir bud s located at the soil 's
sur fa ce . Per en nial an d bien nial her b s f all wit hin t his lif e- for m group .
Cryp t op hyt es have t heir pe re nn a ting tiss u e in r hi zomes . tu bers , and bu lbs whi ch
ar e loca t ed well b elo w the surface of the grou n d . Therop hytes ar e annual plants
whic h survive unfav ora ble s eas ons in the form of see ds. Plan t lif e f orms and
rela t ed con cep ts contin ue t o develo p and to be us ed in th e stu dy of vegetation
dynami cs S, 11 .
Dec iduo us leave s of drought into lerant species generally wilt when water
defi cits dec line to around - 15 ba rs water potential? Everr-een leave s s how no
immediat ely visi b le si gn s of water stress at -15 bars . Water po tential
meas ure men ts u n d er normal conditions in t he growing season have yie lded results
ra ngi ng from - 1 b ar s in aq uatic plants, to - 7 b ar s in chi ckweed ( Stellaria media) 13
to - 4 to - 10 b ars in several species of Viola in New E ngland~4 b ar s in
Amer ica n Holly (H ex ~)15 to - 52 bar s in spruce (Picea .J2!!!!~!!§) 13.
SIT E DESCRIP TIO N
Hemps t ea d Plains is situated on out was h depo si ts of th e las t Wisco n sin
glacier. Two soil groups, Haven Vari ant Associatio n and Hoos ic Variant
Ass ocia ti on, were identified at the study site 17 . Have n Variant so ils are deep,
well -drai ne d an d mediu m textured. occ upying nearly level t o gently sloping
ou twash p lai ns . Hoosic Variant soils are deep, very gravelly and well drained .
Clima tically, Hempstead Plains is classified in the Coastal Division of Ne w
Yor k s ta te". The ave rage ann ual temperature is 11.6 degrees C, with an average
rainf all of 1 .13 m/yr . Hurricanes and summer droughts have been recorded
per iodically. The average length of the growi ng season is 187 days with the
shor test recorded duration be ing 158 days and the longest duration be ing 217
days .
VEGETATION
Bro omsedge b lues tern (Andropogon vfrgtnfcus ) and lit tle blueslem (A
scoparius) were the dominant pla nts at 'Hempstead Plains in 1986. Grass-leaved
goldenrod (So lidago graminifolia ) is the mos t common goldenrod follo wed b y
Cana di an golde nrod (.2.:.. canadensis) . As ter (Ast er pilosus) is common throughout
and esp ecially con sp icu ou s when in flower . Fescue ( Fes tu ca sPP.), poverty grass
(De ntho nia spica ta), or chard grass (Dactylus glomerata), Indian grass
(So rgha strum nuta ns) , a long with little bluestem and broomsedge bluestem are
pr es en t t he year round and demonstrate the importa nce of grasses at Hempste ad
Plain s 16 . La nce - leaved vio let (V iola lan ceolat a ) , wild indigo (Baptisia tin ctorta) ,
St. John 's -wo rt ( Hyp eri cu m p erforatum), Queen Anne 's lac e ( Dau cu s carota) ,
Gr -een's rush ( Ju n cus greenei) , hawkeeds (Hieraciu m) spp ., and sedge (Carex
p ens y lva mca ) are also common and/ or dominant in portions of this tra ct. The
in vasion of alie n sp ecies, crab gra sse s (e. g. Digi ta ria ischaemum, Q..:..sanguinalis,
and fox tail grass Se taria fa b erti) .on distu rb ed sit es reflec ts th e gradual change
tha t is occur ri ng in the Plain s ve g et ati on 16.
METHODS
Th e vege tati on of an 8 ha tract of Hempst ead Plains was collected on a
week ly b asi s b egi n nin g on April 12, 1986, t ermina ting on Oct ob er 15, 1986 . A

58
of Gleason &. Cro nquist ....... Baile y "' was used to identify cultivated spe cies. Th e
specie s were arranged in a Ra u nki er life form. spectrum . Pro porti ons of spe ci es
in ea ch of the five lif e forms were cal culat ed (T abl e 1).
Lea v es and t wi gs of 94 spe cie s re p resen te d by 50 or more plants in a 8 ha
trac t at Hemp stea d Plain s were har vested durin g 12 samp le p eriods beginning May
30. 1986 ter minating May 1. 1987 . Leaves and t wigs we re ex cis ed near midday and
xyle m water potential was meas ured with two cross-cal ib rate d Sch olander type
pressure chambe rs, one reading to - 40 bars and th e othe r to - 100 bars
(Soilmoisture Corp ., Santa Bar bara, CAl . We were ab le to make large numbers
of measu r emen ts within several hours by usin g tw o cham b ers and three
in ves tiga tors.
RESULTS
Hemicr-yp tophyte s , the largest life form category , comprise 38 perce nt of th e
plains fl ora . Chamaephytes are least represente d (Table 1).
Water p ot en tials for phan ero ph yt es and chamaeph ytes are lowest in winter
whil e the p r otected h emicrypto p hyt es and cryp tophytes are highe st (least wa ter
stres se d) in win ter. Gene rally , th ero ph yt es are th e least wate r s t re s s ed of all life
form spectra thoug h som e the rophytes e. g. Deptford pink (Dia nthus armeria) , may
de ve lop wat er po ten tials as low as - 49 bars when in flower or in frui t . T he re is
a gre at deal of va ria bili ty of wat er pot ential within ea ch life form catego ry fo r each
da te , in ea ch se aso n (Table 3). An exce pti on to this generalizatio n is th e fact
th at water potentials were no t measured for the ro p hytes in win te r . Gen erall y , th e
fre que ncy dis tributions we re hig hl y statis tically signifi can t for sk ewness and for
lepto ku r tos is for each life for m ca tego ry for each season (Tab le 3). This tendency
toward skewness and kurtosis held true in winte r under blizzar d co ndi tio ns (se e
22 Ja nu ary 1987 in Ta bl e 3).
Water p ot en tial s for all lif e form spe ctra were lowes t (Le . un der th e gre atest
amou nt of water s tre s s ) in win ter and high es t during late July , earl y Sep tember
an d ea rly Octo ber. 1986 . Chamaephytes expe ri en ce d greate s t wa ter stre s s,
esp eciall y in winte r whe n dewberry (R ubus flagellaris) develope d a mean wate r
po te ntial of - 58 bars. The plain s species tes te d in five life for m ca tegories
deve loped s ignif ica n tl y diff er en t wat er potentials during the yearly te st pe ri od ;
extre mes were greatest fo r cha maep hyt ea ,
T he freq uency dis tri bu ti on was highly s ta tis ti call y significant (P < . Ol ) for
nega tiv e ske wness an d for lep to ku rtosis for the entire data se t (gl =: 1. 9; g= ­
7.6 ;). as well as on 7 of th e 12 sample days and for the dif fe ren t lif e fo rms .
Relative to nor mal p rob ab ilit y distri butio ns, our samples had mor e extre mely low
wat er p ot en tial values, an d had more val ues clumped arou n d th e mean . Wat er
p otentials were highest in th e fall an d were lowes t in the win ter (Ta b les 2 & 3).
Th e means for th e s eas ons were heteroge neou s (singl e clas sification ANOV'A, F =:
11. 2 n. , df 3, 1198); ove r all se aso ns , th e means for the five life fo rms were
h eterogeneous (single clas sifica ti on ANOVA, F =:12 .2 ... , df 4.119 7); an d within
eac h season , the means for the life forms were he terogeneous (P < . 01 in all cases;
Tabl e 3) .
Durin g th e growin g seas on . mean wate r po tentials for all speci es va ried from
- 17 to - 9 . 3 bars (Tab le 3). Plains sp ecies d evelop si gnif ica n tl y different wa ter
potentials during any t est period (Table 2).
Th er e are few phanerophytes and chamaephyt es at Hempste ad Plains . Most
plains species (hemicryptophyt es, therophyt es and cryptopbytes) have their
perenn ating ti s s u e prote cted during th e unfavorable part of the growing seas on .
Stra t egies s uc h as un der gro u nd p ro tecti on of meris tematic tissue linke d to
varia ti ons in th e seas on alit y of gro wth , an d combine d with dif ferential wate r

59
re la tio ns , may assis t in the extra ctio n of soil wat er and all ow surviv al and growth
during drought indu ced water stre ss . The pre se nce of th e p re dominantly
herbaceous vege ta ti on at Hempstead Plains may in volv e wat er re la ti ons as well as
life his t ory strategy. and s tage in succession .
Tabl e 1. Freq ue n cies of specie s in Raunkia er Life Forms for Hemp s tead Plains,
Long Is land N.Y. (171 species ).
Freq uen cy
Numbe r of (Per cent )
Sit e Speci es Ph Ch H Cr Th
Hempst ead Plain s 171 26 66 34 42
Lon g Island, NY (15%) ( 2) (3 8) (2 0) (2 5)
LIT ERATURE CITE D
1. B~YJ L .K. 1949. Manu al of Culti va te d Plants . MacMillan, New York .
2. Chabot , B .F. and Mooney , H.R. 1985. Physio logical Ecology of North
American Plant Communiti es. Chapman &: Hall, New Yor k .
3. Cu r tis J W.F. and Kin caid. D. T . 1984. Leaf con d u ctance r espo ns es of Viola
species from s u n and shad e habitats . Cana dia n J ournal of Botan y . 6 2 :1268~
4 . Gleason , H.A . and Cronquist , A. 1963. Manual of Vascular Pla n t s of
Nor th ea st ern United Stat es and Ad jac en t Canada . Willard Gra n t Pres s , Bosto n,
MA.
5. Hobbs, R .J., Mallik, A .U . and Gimin gham, C.H . 1984. Stu di es on fir e in
Sco tti sh HeathJan d communi ties III. Vital a ttr ib ut es of the speci es . Jo ur nal of
Ecology. 72:963 -976 .
6. Kin cai d . D . T., and Lyo ns , E.E . 1981. Winter water relatio ns of red spruce
on Moun t Monadn ock , New Hampshire. Ecology 62 : 1155 -11 61.
7 . Kramer , P. J. and Kozlowski , T. T . 1979. Ph y siology of Woody Plant s .
Academic Pres s, In c . , N .Y .
8. Lar che r, W. 1980. Physio logical p lant eco logy , 2nd ed . Sp rin ger - Ver la g ,
NY.
9. Pa ck, A. B. 1972. Climate of New Yor k . United State s Depa r t men t of
Commerce . Nati onal Oceani c &: Atmosph eri c Admini stration, Enviro nme n tal Data
Ser vi ce. Silver Spring, MD.
10. Raunkia er, C. 1934 . The Lif e -F orms of Pla n ts an d Statistical Plan t
Geography . Oxf ord Uni ver sity Pres s , London .
11. Rea der , R.J., Mallik , A .D . , Hobbs , R .J. and Gimin gham , C. H . 1983 .
Shoot regeneration af te r fire or fr eezing t empera tures and it s relation to plan t life
form for some heathland species. Vege tatio . 55 :181 -189.

60
12. Sala , O.E . • Lauenroth , W.K. and Reid , C.P .P . 1982 . Water rela ti ons : A
new dimension for niche separation betwee n Bauteloua gracilis an d~
smit hii in North American se mi-arid grasslands . Journ al of Appli ed Ecology.
19 ,6 47-657.
13 . Salis bury . F.B .• and Ross , C.W. 1978 . Plan t Phys iology, 2nd ed ,
Wadsw orth , Belmon t , CA.
14. Sakal, R .R . , and Rohlf. F.J . 1981. Biometry, 2nd e d, W. H. Freeman &
Co., San Francisco.
15 . Stalte r I R. , and Kincaid , D . T • 1985. llex opa ca on Fire Is land - Water
Relations in Winter at The Sunken Fore st . Holly Society Journa l. 4:1 -12 .
16. Stal ter, R . and Lamont , E. 1987 . The vegetation of Hemps tea d Plains ,
Mitchell Fie ld , New York. Bulletin of th e Torrey Botanical Club. 114:33 0- 335 . '
17 . United States Soil Conservation Service. 1976 . Gene ral soil map and
int erpretation, 1976 . E. P .A . Grant 1002103010 . 51 p., 1 map .
Table 2. Dat es, sampl e sizes, and means for xy lem water po te ntial meas ure d at
Hemps tead Plain s.
DAT E NO . NO . MEAN SD
SPEClE S SAlIIPLES ( -bars)
30 May 30 1986 25 92 -15 .3 7 . 26
9 Jun e 1986 40 181 - 10 .4 3.9 7
27 June 1986 37 89 -17 . 0 8 .55
22 Jul y 1986 45 0·0132 -12 .5 4.99
Skew Kurtosis
+ ••
NS +.
+ ••
+. NS
29 Ju ly 1986 54 149 - 9 .3 4 .22
2 September 1986 53 138 - 7 .9 3. 78
3 Octo ber 1986 46 120 - 7 .9 4.12
14 Nove mbe r 1986 20 56 - 13. 8 7.90
11 Dec embe r 1986 19 54 - 8.3 5 . 91
22 January 1987 10 28 - 24 .3 12 . 01
6 March 1987 13 38 - 15 . 1 9.79
NS
NS
N5
NS
+ ••
+ ..
+ ••
+ ••
+ ••
1 May 1987 40 125 - 9.2 9.16
+... NS
+ ..

61
Table 3 . Midday xylem water potentials for Raunkiaer life forms. Hempstead Plains. New
York .
A. Means in Xy lem Wate r Pote ntial
LI FE FOR M SPRING SUMMER FALL WINTER OVERALL
Phan erop hytes
- 10. 1 - 13 . 1 - 11. 9 - 15 . 8 - 12. 7
n =305
CV 53\
Chamaephytes
-11 .3 -10. 7 - 0.9 - 20 . 1 -14 .2
n = 33
CV 107%
Hemicryptop hytes
-12 .4 -11 .4 -9.3 - 6 . 9 -11.5
n = 350
CV 50. 3\
Cryp t op hytes
-10 .5 - 10 .4 - 10 . 1 -6. 2 - 10.2
n = 414
CV 59.2%
T he rop hytes
- 9. 2 - 9 . 5 - 6. 2 absent - 8. 6
n = 100
cv 66. 8\
Means
CV (\)
N
- 11 .0
49%
423
- 11 .1
56. 2%
502
- 9. 7
63.5%
157
- 14. 2
76 . 7\
120
GRAND TO TAL
Gra nd Mean -11. 2 bars
CV = 59.5 %
n = 1202
B . ~B in Xylem Wate r Potential
LIFE FORM SPRING SUl\1MER . FALL WINTER
Pha n erophytes
-19 to - 1 - 22. 5 to- 1 -4 5 . to - 4 -39 to -3
Chama ep h yt es
-14.3 to -8 - 20 to -4.5 - 1 to - 0 . 8 - 58 . 5 to 1.5
Hemicryp top hyt es
-40.5 to -0 .5 -40 to-l - 18 to-1 -10 to - 3. 5
Cryptophyte s
-34 to - 0 . 1 - 40 to -1 - 26 . 5 to- 1. 5 - 14 t o -2
Therop hytes
- 11. 2 to - 7 . 5 -4.9 to - 0 . 6 -12 to -1 abs en t

62
TIMI NG OF OUST APPLICATION AFFECTS SURVI VAL OF HARDWOODREGENERATI ON:
NORnl WESTERN PENNSYLVANIA
Stephen B. HO rSl ey~
Larry H. McCo1'1lick
ABSTRACT
Dense ground covers of' hayscented (Dennstaedtia punct ilo bul a (Michx . )
Moore) an d New York (Thelypt eris novebor-ecenad a L.) fern , pe r ennial g rasses ,
and sed ge s (Car ex sp p . ) int erfere with establish ment of ad vance r egenera tio n of
blac k ch er r y(Pru nu s serot me Ehr h .) and r ed mapl e (Acer ru b ru m L.) i n t he
Alle gheny hardwood forest of nor t hwest ern Pennsy lvania:---oUS t her b i ci de
(s ul f ome t uro n methyl) cont rol s hayscented and New York fern and reduces the
amount of gr a s s and sedg e o rigi na t i ng in t he f ore st fl oor seed bank when
ap pli ed at t he rat e of 2 o z of produ c t / a cre between e arly J u l y and early
Octo be r . Measurement s made in fo rmal studies an d obse rvat i on s mad e in
comme rc ial opera tio ns su g ge s t t h a t ha rd wood species may diffe r in se ns i t ivity
to Oust . I n 19 89. we initi a t ed a small pl ot e xper ime nt to de te r'lline the effect s
o f timing of Ous t ap plic a ti on . su r f a ctant add itio n . an d se ed l i ng size on black
ch e r ry and r ed mapl e s eed li ngs of s eve eef sizes . A si mi l ar expe r-rcnen t , whi ch is
r-epo r -te d sep ar-a t.ek y , was c ondu c t ed i n ce ne s-ef Pe nnsy l van i a .
Oust was applied with o r wit h out surfactan t (0 . 5% Va l an t X-77 Spr'ea der-] at
the r ate of 2 oz o f produc t /a cre in earl y July, early August. early September,
and e ar-Ly Octob er to t h r e e si ze catagories (new get"minants ,

63
TIMING OF OUST APP LICATI ON AFFECT S SUR VIVAL
OF HARDWOO D REGENERATION:
CENTRAL PENNSYLVANIA
Larry H . McCormick I
Step hen B. Horsley2
ABSTRACT
Regenerati on of hard wcxxis in central Penn sylvania is often impeded by den se
gro und covers of ferns and perennial grasses which invade fores t sites followin g harvest
cuts. Oust herbicide (sulforneturon methy l), which effectively control s ferns and grasses.
has been used operational ly in forest management in Pennsylvania since 1987. Report s on
theeffects of Oust on seedlings of desired hardwood species present at the time of
herbicide applications are conflicting. In someinstances, OUSIhas not producedany
detrimental effects on de sired tree seedling s while in other instances Ous t has caused
seedling mortali ty or severe stunting . These confl icting results may be due to difference s in
species sensitivity to Oust, the time of Oust application, presence of a surfactant in the
spray mix, or size/age of the seed lings. These factors were eval uated by a set of similar
experiments conducted in north western and central Pennsylvania. Thi s abstrac t reports on
the rese arch condu cted in central Pennsy lvania; the northwes tern Penn sylvania work is
reponed separate ly.
Oust was applied with or without surfactant (0.5% Valant X-77 Spre ader ) at the
rate of 2 oz of prod uct/acre in early July, early Augu st, early September , and early Octobe r
to three size categ ories (new germinant s, < 1', 1-3') of red maple (Acer rubrum L.) and
two size catego ries (new germi nants. 1-31 of white ash (Fraxinns ameri cana L. ) to
evaluate the tolerance of these species to Oust Survival and damage of treated seedl ings
were compared with a no herbicide control one year after treatment, Similar measurement s
were taken on northern red oak. (Quercu s Dlbra L.) and black oak. (Quercus yelutina Lam. )
seedlings present in the red map le and white ash plots, although there were not eno ugh for
statistical testing.
Red maple showed little sensitivity to Oust irrespective of the month of application
or the prese nce of surfactan t Surviva l of red maple seedlings was high (>85%) for all
three size categories of treated seedling s. White ash was more sens itive to OUSt White ash
mortality was high with applications made from early July through early September. Early
October applic ation of Oust resulted in lower monalit y of white ash. Addition of surfacta nt
to Oust significantly increased dama ge and mortality of white ash. New genninants of
white ash appearedto be more sensitive to Oust than older, large r seedlings. Northern red
oak and black oak were not sen sitive to application of Oust alone. Survival was less when
Oust + Surfactant was applied, particular ly with earl y July applications. The se results
suggest that sites containing white ash rege neration should rece ive late summer or ear ly fall
applications of Oust witho ut surfactant
I Associate Professor, Schoo l of Fores t Reso urces, The Penn sylva nia State Unive rsity,
University Park, PA 16802.
2 Plant Physiologis t, USDA Fore st Service, Northeastern Forest Expe rime nt Station ,
Warren, PA 16365.

64
CONTROLOF HAYSCEN1ED FERN SPOREEMERGENCEWITH
SULFOMETURON
John W. Groning er and Larry H. McCormick l
ABSTRACT
Partially cut hardwood stands in Pennsylvan ia frequently develop a hayscented fern
IDenn sraedtia punctilobu!a (Michx.) Moore] dom inated understory. Fern inte rference and
overbrows lng by deer prevents the establishment of desirable hardwood seedlings
frequently leading to regeneration failures. Previously fern free areas can be colonized by
wind dispers ed spores Ferns developing from spores produce a perennial rhizome during
their first year and can become sexually mature in three years. Ferns developing from
spores have been observed in recently partially cut central Pennsylvania oak stands.
Preventing the devel opm ent of these individuals can be crucia l in maintaining a stand's
regeneration potential. Sulfometuron is currently used to control hayscented ferns when
applied to fronds and unfoliated rhizomes. Its ability to control spore emergence is
unknown.
A greenho use study was conducted to determine the effectiveness of varying rates
of sulfometuron in controlli ng hayscented fern spore emergence. Sulfometuron was tested
at rates of .025, .05, .1 and .21 kg ai/ha plus an untreated control. The herbicide
treatments were applied to mineral soil samples prior to inoculation with hayscented fern
spores collected from fertile fronds. Inoculated soil samples were placed under a 55%
plastic mesh shade cloth and spore emergence status was evaluated after 52 days.
Sulfometuron effectively controlled hayscented fern spore emergence at all rates
rested. Abundant prothalli (the second observable stage of fern emergence) were present in
all untreated controls.
IGraduate Research Assistant and Associate Professor respectively,
School of Forest Resources, The Pennsylvania State University, Univer sity Park, PA
16802

65
ELECTRI CAL CONDUCT IVIT Y OF TWO GLyP HOSATE-C ONTAI Nf NG HERBI CID ES
AT F I VE CONCE NT RATIO NS .
R . A . l_d ut e n sc h l ag er an d G. R i cha rd Sc h ae rtl . Co l l e g e of Fore s t
Resources, Unive rsit y o f Ma i ne . Or ono, ME 0 4 4 6 9 .~
ABSTRACT: r-tee e .ur t nq co ndu ct ivity o f spr a y e o l u t r o r-s o f em i ne
h er bi cid es h e lp s ass u re prope r mi xi ng pri o r to a p ol l Ca t l o n t hus
p r o vi d i ng ad d Iti o nal q u alit y c o ntr o l t o op er ation a l h erb I c I d e
p r o gr a ms . E le c trica l con d u c tiv ity was d et e rmi ned f or $e Ve n
c o n ce nt rati o ns (0 - 15 % v :v) o f Accor d R a n d Ac co r d R CR h e r bi =id e s
i n aqu eo us s olu tion with t h ree concen tr ations ( 0 - 1% v : v) o f
eit he r Cide - Kick I I ~ m o r Or-th o X-77 Spr e aderH 5urfact ants .
Co n dcc t t v i t v ( f.JS cm · -~) of th es e solution s, o e t e r-m i n e -d at f i v e
sol utio n t emp e ra tur es (5 - 25 ""C > inc reas ed 73 7 . 7 j.lS c m- l and
16 4 . 9 ~S cm I for ea c h 1'l. in cre ase in h e r b i C l d e co nc e n tr a tio n a n d
ee cb ! "·C lnc r e e s e i n t e mp e r a t ur e . Con d u ct i V1 ty d e cr e a s ed 21 2 .3
u S e m ,-l fo r each 1% inc rea s e in su r fa ctan t c on c e n trat1 0 n . Th e
c o nd u c t i v i ty o f Ac c o r d CR was 100 . 5 ~ S em ' gr e a t er t na n Ac c cl - d :
c o nducti vi t y of Ci de - Kic k 11 was 82 .3 ~ S e m ·' g ,·e a t e r than X- 7 7 .
Re su l t s o f th is s tu d y wi ll a p pear in t h e South e r n J o u r na l o f
Applie d F ores tr y in 1991 . Th e e q u a t 10 n s p re sente d WIll e na b l e
fore st ers t o v er i f y proper co nc en tr a t I on an d mI r i n g o f th es e
h e r bicid e a n d s u r f actant so luti o n s fo r te mpe ~a t u , es Ilk@l y t c
occ u r in the f i el d if wa te r source c o nd u c t iV Ity i s ~ 31)0 u S C"
'- Th e e o t nor e than k .Lo t- m Br v eo t • Oe vi o 00\\1 , An t n on v O:l la u l 0 ,
WIll i am Ha l t e ma n , eo d Ma )Cwell rtc Co r-me c c J r . f o r c r r v t c e t r e v r e we
of this meo o ec r r o t ; t h e u ru v e r e r e v of rte r o e t e C c c o e r e e r v e
F o re s t r y Resear ch Uni t f or labo rato r y f aci l Ities ; a n d th e
etc n e eo t c Agr i cui tura 1 Com p an y f or f u ndi ng.

66
P'IRS'r -'l£AR RESPONSE OF NORTIlBRH HIDD CONIFE R STANDS
'1'0 RELEASE APP LICATIONS OF l MAZAPYR AND COMBIN AT IO NS
D. r • Maa •• l
Tr ea t me nts of lo w r at e s ima zllpy r alone a nd ta nk mi xe s wi t n II. surfactant.
g l yp ho s &t e and t r l c l op yr r ed uced broa d l a a! stems f rom 72' t o 96 ' . whi le tre at ­
ments wit h gl yp ho sa .te and t r ic lopyr al o ne r ed uc ed stem number s by 63 \ and 64\
i n this s t udy o f a ppl i c at i on ll t o ill ten ye ar o l d fo r e s ted cl eareut in Hain e .
Fi r and spr u ce he i ght g r owt h r a tes were 0.1 to 0 .2 fe e t in the first year with
ap plica t i ons o f ima z apy r . Fir biomass grew i n t he glyphosate and imazapy r
tre at me nts g re w bett e r th an th e co nt ro l .
Int rodupti o n
Ima zapy r {(±1 -2 - {4 , S-d i hydr o- 4-m e thyl-4 - (l - methy l ethyl) ­
S- ox o-l H- im i d a zol- 2-y l }- 3- pyri di necar bo c yli c a ci d }2 ha s be en u se d in Main e on
19 di ffer ent s it e s in 15 diff e r ent treatme nts b e t wee n the yea r s 198 5 t o 1988.
Tr i als wer e e stablis hed t o de t ermin e eff i cacy and i njury l e vel at d i ff eren t
ra t es and a s ta nk mixes for r e lease of nort her n coni f ers , si t e pr epar ation and
r o adsi de br u sh c on t ro l. For r eleas e, lo wer r at es hav e r e duc e d injury, bu t
ha v e low ered e f fica c y on s ome spe cies.
Th i s series of t r e a t ment s was established to examin e dif f e renc e s in ef fi ­
cacy and co nife r injury at varying low r ates o f i..mazapy r a pplied a lone , wi th a
sur f a c tan t 3 lind as a t a nk mix wi t h g l yp hos llt e {N- {ph o s ph o nOllleth yl} gl ycinel 4,
an d tric lopyr (I (3,5 , 6- tri ch lor o- 2-py ridinyl )ox y ) ac e tic acid) 5. These
tria ls we r e de s i gned t o mini mize c o st a nd environment a l inp ut of p roducts .
The t r eatm ents (Tab le 1) wer e a pp lie d to a fo r es ted cl e arcut ab out t en
years af t e r har ve s t ne a r Endles s Lak e i n T3R9NWP a bout 45 mi les nor th o f
Bango r. Th ey wer e a pplied a e r i a l l y on Se ptemb e r 5 a nd 6th , 1989 during ev e ­
ning se8sionll usi ng RD- S·s no z zles o n a Bell 4 7 Hel i c opt er . The tr iclo p yr
tre a tments were applied a t 8 gallons per acre. All the othe rs wer e a pp l i ed a t
5 gallons per acre . All t r e at ment s were a pp l ied to live acre blocks wi t hou t
r e p l ic a t i o n.
The t r eatm ents f or ea c h b lock were s elect ed ran doml y . Beca use the blocks
were not t r e a t ed consecutively , care was take n to assure trea tmen t s were
a pp li e d a s planned .
The ba s i s f or comp aris on of treat ments will be ch ang e s in b road leaf
spec i es a nd growth o f co ni fe r s wit hi n ea c h t r e at ment. To ex ami ne th ese
cha nges , s ixte e n sam ple points wer e es t a bl i sh ed i n e a c h blo ck c o nsi sting of a
mil ac re plot and a 1/1501'. plot . These we re dis t rib uted on a gri d pa t ter n
throughou t the treatment area. The perm anent pl ot cen te rs were e stabli s hed
be f or e a ny d ata was coll ected . Each pl ot c e nt e r was lab elle d wi t h b l ock an d
p l ot nu mber.
1 Associat e , Th e Irland Gr oup , August a, Haine
2 Ar senal Applicators Concentrate €)
3 Ci d e Kic k II ®
4 Roundup@
5 Ga rlo n 4 €, l

67
l mazapyr
...Alone
I ma z a p yr '01/
Surfa c t a nt
L..2ll...l1LY
'rabl e 1. Tr. at •• n t li st :
ounc e s of iJla wapy r prod uc t per acr e
I maza pyr '01
Gl yp ho s ate
--LLll11AL
I ma z a p yr '01
Glyphosa t e
~
I ma z a pyr wI
Tr i c l o p yr
tl 5 I b /A I
Glyph os at e pr od u c t a l o ne @ 2 Ibs / A
Triclop y r pr odu c t a lo ne @ 2 l b e tA c o nt r o l
Unt rea ted co ntr o l
The mi laer e pl ot wil l be us ed to monit or c ha n ge s in br oa d l e a f spe c i e s
su r vi va l a n d he ight by exami n i ng c ha nge s s t e m c o u nt of ea c h spe c i es pr e s en t
and a n es timat e of he ight . The larg e r co nce nt r i c plo t wi l l b e u s ed t o measu re
c ha nge s in surv i v al and g r owt h of th e r el e a s e d con i fe r s . I t was div i ded in to
four quadrats ba s e d o n or d i n a l direc tions . This i s e qu iv a l e nt to a 1/ 600 A
plo t . The d omi n a nt in di vi d ua l o f eac h conif er present i n e a c h qu ad r at was
mar ked a nd he ight a nd d i ame ter at 6 i nche s wa s mea s u r ed . The p l o t a we r e will
be measu red for t wo g r owin g season s foll o wing t re a t me n t s . Th i s p a per r epo r t s
on the f i r s t g r owi ng s e a s o n follow ing trea tment measure d in Ju ne , 1990 a t t he
e nd o f t he h ei g ht e xp an s i on fo r t he ye ar .
From g ene ra l obse rva tion , the trea tment s appear ed to be s u ccessful .
The r e . seeme d to be unifo rm a pp l i cati o n throughout e a c h bloc k and across t he
tr eatm en t a rea .
Al l t rea t men t s h ad acc eptabl e levels of cont rol . While the control
inc r e as ed th e numbe r of h a r dwood s t ems per plot by 15" , the chem ical tr eat ­
men t s r e du ced ha rdwood stems fr om 63 \ t o 96\ (Table 2 ) . The glyphosa te a nd
t ri clo pyr a l on e t r e a t ment s reduc ed har dwood stems a t 63\ a nd 64\, wh i l e
t rea t men t s wit h i ma za py r reduc ed s t e ms by a t least 11'l . Gen e rally stem re d u c ­
t i o n increase d wi t h i n cr e a sed amou nt of i mazapy r a p p l ie d, but i ma za pyr at six
ounce s was margi n a l ly b et t e r tha n ima zap yr at two o r f o u r ou nces . I ma z a p y r
a lon e at si x o un c es r e d u ced the nu mber o f stems pe r plot by 87\ i n th e fi rst
yea r . Th e imazapyr and s urfac ta nt co mbinat i o n re du ced s tem s by 73\ to 80 \ ,
while combina tions with g l yp ho s a t e r e du c e d st ems fro m 8 2\ t o 9 0\ . Combi na ­
t i on s with t ri c lo p yr r e d u c e d s t e ms f r om 7 1\ t o 96\ .
Tabl e 2 . Percent Lo ss in Ha r d wood Stem s
No I ma z a py r Imaza p yr I ma zap y r
1IllJWlJ>U .L'--.o.L. lL.Lo.L. L.O....=..
No o t he r produc ts - 14 . 8 87.1
Sur f ac t ant @ .2 5\ vl v 12 .8 80 .4 79 .9
Glyp ho s a te @ 1 lb. 86 .0 82. 4 82.5
Glypho s at e @ 1 1 {2 Ibs . 84 .7 93 .3 89 .6
Gl ypho s a t e @ 2 lbs. 62.8
Tricl o pyr @ 1 1 /2 lbs. 11.7 70. 7 95 .7
Triclo p yr @ 2 lbs. 63 . 8

68
Cherry ( PnmuB pensylyanica L.) and ae pen l~ Bpp. L.) we r e the
e •• i est to c o nt r o l lind all t reatments were s uc c e s s f u l with t hese s pecie s.
There WllS s ome va riation in red map l e (~ ruburm L. ) stem r edu ction wi t h th e
g l ypho s ll.t e alo ne trea tme nt havin g t he sma ll e st r ed ucti on a t 16\ a nd i ma:z:apyr
a nd surfa ctant hav i ng t he l arg e s t r edu cti on of 94\ an d 9 5\. Ho o se maple (~
pe ns y l Vllni c um L.) was als o r e l a t iv e l y ea si l y c ont rolled for most treatm ents,
wit h re du c t i on s bette r than 82' . Glyph os llte a lo ne and tr lc! opyr a l o ne h ad
reduc tions of moose maple of 26\ a nd 40\ respectively .
There wa s more v ariation in control of beech (~ g randifoli a Ehr.) .
Reductions i n per cent of stems per plot varied from 35\ fo r tr l c l op yr a lo ne
to 95\ for lm azapyr at 4 oun ces in combination with gl yp ho sa t e . I ma zapy r an d
s u rfac t a nt combi nati on resu l ted in a l owe r r eductio n than ot he r co mbinat io ns.
Gr owt h of spruc e (f..i..m spp. A. Di e t r. ) a nd fir (illll ~ (L. )
Mil l.) is i nhibited by imllzap yr at ra tes exceeding 4 ounce s pe r a c r e
(Sc haertl, 19 91 ) . We would e xpe c t to see less growth occur ring at h i g her
r a te s of imazapyr than at low rates. This generally the case (Tabl e s 3 an d
4) . I n the control, f i r grew 0 .5 feet and s pruce grew 0.3 feet. Mo s t of
th es e tr e e s are und e r stress due to compet i tio n . I n the glyphosat e trea tm ent ,
fi r grew a t a modest r ate of 0. 1 feet and sp ru ce 0.5 feat , whi le in t he
t r i c l opy r a lon e t rea t ment , fir grew 0 .5 a nd s pr uce gr e w 0 . 4 fe e t. Wit h the
ex c e pt io n o f on e treatm ent, fi r an d spruc e grew between 0 . 1 and 0.2 feet for
the fir s t gr owi ng se a son af t e r trea t ment in th e block s t r e ated with combina ­
tions with imazapyr. The comb ination s of t r iclopy r a nd ima za.py r had v ery
modes t growth on s pruce and fir and seemed to be most in hi b ited . In j ur y rat e s
were highest amongst these t reatlllents. The negative growth of the s pr u ce i n
the triclopyr and imazapyr at 6 ounces is du e to IlIOrtality due to ins e ct a an d
litt l e positive g rowth on other trees. Only in the treatment of th e combi na ­
tio n o f imaz apyr at 2 ou nces and glyphoaate at 1 lb . did fir growt h compa r e t o
t ha t of the control .
Table 3 . Fir Growth i n Fe et
No IlIIazapyr Imazapyr I maza py r
Imm JL'--.oL. ~ ~
No other p r od uc t s 0 . 5 0. 1
Su r f a c t an t . 25' vjv 0.1 0 . 1 0. 0
Gly ph o sa.te •@ 1 lb. 0 .5 0 .0 0.1
Gly p ho sat e @ 1 1/ 2 l b e. 0.2 0.2 0 .1
Glyphoeat e @ 2 Lbe , 0 . 1
Triclopyr @ 1 1 /2 Ibs. 0 .1 0. 1 0. 0
Triclopyr @ 2 Ibs . 0 .5
Table 11. Spruce Growth in Fe et
No IlIIazapy r lmazap y r I maz a pyr
Imm JL'--.oL. e...L=,. LJi....l>L.
No other produc ts 0.3 0 .1
Su r f a c t a nt @ . 2 5' vjv 0 .2 0 .2 0. 1
Gly ph o s ate @ 1 lb . 0.2 0. 2 0.2
Gl yph o sate @ 1 1/2 Ibs . 0.2 0 .2 0 .2
Glyp hosa te @ 2 Ib e . 0. 5
Tr i c l o pyr @ 1 1/2 Ibs . 0.1 0 .0 - 0 . 2
Tr i c l o pyr @ 2 Lb e , 0.4

69
I maz apyr i n j ury on s pr uc e a nd fir con s is t s o f no o r lit tl e bud bre ak or
s mall nee dles or both i n t he gr owing s e a s on f o l l owi ng application . Some burn ­
ing of t he need lea also o c cur s. Obs er va t i on s from prior ap p lications indi c at e
tha t t he t rees r e c ove r afte r tw o o r thre e gr owi ng seasons . White pine (Pinu s
~ L .) wer e not AS s u s ce pt i b l e to injury at these rates ee t he spruceand
fir.
Estimates of biomass wer e c alc ulated usi ng diameter squared times height .
Flrst year firm a nd spruc e b iomass growt h are shown in Tables 5 and 6. These
ellttlmate8 demon lit rate t he impo rta nce of diameter growth. Those treatmen ts in
which diameter did not g row very much also had poor biomass growth . It is
appa rent , that we should not re l y solely on height growth as measures of
response.
Fir in all the t reatments grew as well as or better than the fir in the
control. However, spr uce in th e cont ro l grew better than the spruce in all
but two of the treatments. The be s t fir and spruce growth occurred in t he
glyphoaate and imll.z;ll.pyr combinations .
Table 5. Pir Bi o_.. Gro wth
No Imll.z;apyr lmazapyr Imazapy r
Imaz apyr ~ lLLoL. ~
No other products . 00 3 .003
Surfactant @ .25\ v/v .007 . 004 . 00 3
Glyphosate @ 1 l b . .019 .017 . 0 18
Glyp hosll.te @ 1 1 /2 lbs . .008 . 02 1 .009
Glyphoaate @ 2 l bs. .008
Triclopyr @ 1 1 / 2 Lb e , . 0 11 .007 . 0 0 1
Triclopyr @ 2 1bs . .00 5
Tabl e 6 . Spruc e Bio aa •• Growt h
No I ma za pyr Imazapyr Imaz apy r
~ ~ ~ lL.Loh
No othe r produc ts . 008 . 002
Surfacta nt @ .25\ v/v . 00 5 . 00 1 .00 4
Gl yphosate @ 1 lb . . 002 .0 0 5 . 008
G1yph o sa t e @ 1 1/ 2 ib e , . 004 .012 . 0 04
Gly ph o s a t e @ 2 1bs. .000
Tri c1 0pyr @ 1 1/2 nse • . 003 . 00 5 -. 028
Tri cl opyr @ 2 Ibs. .001

70
Conc lusi
ons
Applic ati o ns o f low rat e s of imazapyr and tank mixes with g lyphosate and
tr iclopyr we r e a s e f fe c t i ve or be tt e r t h an the ccmmon Ly use d applicati ons of
ei t he r g lyp hos at e or tric lopy r in reduc i ng br o ad le af compet i t io n in ill no r t h ­
er n mixed co ni fe r clear cut. Height gr owth o f t he desi r a b l e spru ce and fir was
r edu ced in the f ir st gro win g aeaa on wi th rates of 4 or 6 ounces of irnazap yr .
F i r bi omass gr owth wa s b est i n combi nat i o ns of glyphosate and imazapyr .
Lit er atu r e Ci t e d
scbee ee i , C .R . 199 1. Glyphosate a nd i mazapy r inter act to r e d u c e com peti tio n.
bu t ma y inju re spruce an d fi r in Maine . Pr oc . NEWSS. Vol . 45 . (in
press ) .

71
EFFECTS OF CLEARCUTING AND FOREST FLOOR DISTURBANCE
ON ESTABLI SHMENT AND SURVIVAL OF RASPBERRY
H. R. Roberts a nd H. Dong !
ABSTRACT
Di s tu rbed (for est floor re move d ) and und i sturb ed (contro l) p l ot s we re
mon it o r e d over tw o grOWing s e as ons to dete rmine th e ef fe cts o f f ores t: fl oor
d i stu r b a nc e on r e p r odu ct i on of r as pb e r r y (~ spp. ) and oth er woody species.
In Hay 1988 , 30 pairs of I_m 2 p l o t s wer e e s t ablished after clearcu tting i n a
nort he r n hard wood st a nd i n ce n tral New Br unswick, Cana da . In on e plo t: of ea ch
pa i r, the forest floor was remove d to t he min eral so i l to simulat e l ogging
distu rba nce. The o th e r p l ot wa s left undisturbed as a c on t r o l. Af ter
tre atme n t , t here were 2 mi ll io n an d 316 , 000 ger mi na b l e r a s pb e r r y seeds/ha i n
t he so i l s e e d b a nk in t he und isturb ed a nd distur be d plo t s , respecti vely . In
the fir s t ye a r, mos t ge r mi n a t i on o f r a sp b e r r y occ u r r e d by ea rly June in the
d is tu r b e d p l o t s . Ge rminati on peak e d abou t one mon t h l a ter in t he u ndistu rbe d
plot s. At t h e en d of t he gr owing s e a s on , total ger mi nat i on wa s 304 a nd 123 on
t he d isturb e d and und i s t urbed plo t s , r e s pe c t i ve l y. Surviv al wa s 60% on th e
di stur be d p lot s as c ompa r e d t o 48% on t he un d is tu rbe d plot s. Th e s e pat t er n s
are pr ob ably r e l a t ed to t he more favora b l e seedb e d and micro c li ma t e p r ovid e d
by the ex posed min e ral so i l on t h e di s t u rb e d tre a t me nt . Mo s t of the ra spb err y
s eems observed in this s tudy we re r e d raspb erry ( Rubu s ~ Hichx . ).
After one year, th e re sidua l seed ba nk was sampled from a re as th a t wer e
covered to exclu de see d fall dur ing t he pr evious year. There we r e 47 1 ,000
ge rmi na b l e seectsjh a in t h e undistur be d p lot s a nd 4 1 , 00 0 i n the di st urbe d
p l ot s . In the s eco nd y e a r, tot a l germina t i on and survi val we r e g reater on the
und isturbe d plo t s t ha n the d i stu rbe d pl ot s , the opposi te pa tt e rn f r om the
fi rst year. The l arg er number of s e e ds in t he residua l se ed bank and dela y e d
germ i na t i on on t he undi sturbed pl o t s prob ab ly ac c oun t e d fo r t h is di ff e r e nc e .
At the e nd of two y e a r s, t h e total densit y of woody speci e s was 4 34, 93 0
an d 24 6 , 960 stemsjh a on t h e d i s t u rbed a nd undisturbed p lo t s , re spec tive l y.
Ras pberry account ed for 64% of th e stems on the di sturb ed plots and 45% on t he
undistu rbed p l o t s . On bot h tr eat me n t s , over 75% of the raspb er r y s tems were
appa r ent ly v egetat ive s pro ut s f r om t he rhizomes of t he firs t yea r ge r mi n an t s .
In t h e s e c ond ye ar, tota l veg e t a t i ve cove r was simi lar on t he two t reatment s
bv- diff e red by he ight clas s . Cov er wa s g r eat er on th e un d i s t u r b e d plots in
cue 0 - 10 em and 10 ·3 0 em heigh t c la s s e s but was gr eat e r i n the dist u rbed p lot s
in th e >3 0 cm h e i gh t c la s s. The >3 0 cm h e i gh t c l a s s wa s c ompo s e d mos t ly o f
r a s pb e rry .
On t he d i s t u r b e d pl o ts , r a sp be r r y wou ld p ro bab l y pro v id e more intense
compet i t i on fo r commercia l t r e e sp ec i e s suc h as ye ll ow bir ch (~
allegha n i ens Ls Brit .' . Howe ve r, ge r mi nation , su rv ival an d he i gh t o f yellow
birch were al so gre a te r on th e d istu rbed plo ts t h a n ch e undisturb ed plots. If
r eproduccion o f ye l l ow bi rch is de s i r e d , t he n fore s t f lo o r disturba nc e is
rec ommended i n s p ite o f the ris k of incr e a s ed raspbe rry co mpe ti tion .
' As s oc . Pro f . and Gra d . St udenc , Dep t . o f Forest Re sou rc e s , Un ivers it y of
New Brun swic k , Fre der icton , N. B. , Can a da E3B 6C2 .

72
Eff ect o f Va r ious La nd s c a p e Geote x t i les on We ed Roo t De velopmen t
J . F . Deer a nd B . L. App le ton l
ABSTRACT
Lands c a pe f a bri c s a re b e i ng d e velop ed as a l t e r n a t i ve s t o
s olid po l yet hy le n e p l a s t ic bec ause their p o ro s i t y pe rmits ..... ate r
a nd gas e xc han g e . Four po ly p ropy le n e fa bc i e s (Weed Ba rr le e,
Typ ar, Duon a nd Magic Mat) , thr e e p e r fo ra t e d po ly e t hy l e n e f i l ms
(Weed Cont r ol , Weed Blo c k a nd We ed s t o p) an d one
polye thyle ne /poly e s ter fa b c ic (Wee d - X) were compa r ed to s o l id
brow n po lyethylene (2.5 mil ), sh redded p ine bark mul ch an d a n
untreated c on t rol for sup pression of bermudagra ss (~
~ (L.) ae r s v l and l arge cr a b gras s [Digitar i a s an g nin ali s
(L . ) Se op.) s hoo t and r oot d ev e lopme n t . Plasti c pots (3.8 L)
were fille d with p i ne bark :s a nd , 4: 1 v/v . Fa bric and fi lm pieces
were s t a p l ed t o th e po t ri m a nd a 2 . 5 cm de pth of pi ne ba rk
place d abo ve the ma te r Le Le , La rge cr a bgrass seed o r 3
ber mudagra s s s t o l ons were p l a c ed a t op the mulch in each po t .
Shoot fresh weig ht a nd root weight below the fabr i c o r film were
r e c o r d e d tw o months after stu dy i nitia tion, and t he s tu dy was
r e pe a t e d.
No tre a t me n t c omp l e tely inh i bite d lar ge c r abg r a s s or
ber muda gra s s s hoo t g ro wt h as we ed r oot s e it her devel oped in t he
mu lc h layer ab ov e t he mate r ials o r p e n e t r a t e d down throu gh t h e
fab r ics a nd film s . We e d -X redu ced ber muda grass shoot fre s h
we ight mor e than a ny other fab ric o r film e xcept Weed Con t r o l a nd
Magic Mat. Weed-X redu c e d lar g e crabgrass shoot f resh we igh t
mor e than t he o t he r ma te r ials excep t We ed Control and sol id brown
p ol y eth yle n e . No lar ge c rabg ras s an d f e w ber mudag rass roots
p e ne t ra t ed so li d b r own po ly e th y le ne . Few e r ber mud agrass and
lar ge cra b grass r o ot s penet r a t ed We e d -X a nd We e d Con t r o l t ha n all
ot her ma t e r i a l s exc e pt f or so l i d b ro wn po ly e t hy l e n e . I n order of
least to greates t be rm udag ra s s roo t penetra tion, the treatments
were: s ol id brow n polyethyl ene, We ed -X , Weed Con tro l, Weeds top,
Magi c Mat, We e d Ba rrie r, Typar, WeedBlock and Duon. Fo r lar g e
crab grass , t he o rde r fro m l east to gr e ates t ro ot penetrat ion was:
s ol i d b r own p oly ethy l ene , we e d -x , Weed Can t rol , Mag ic Mat ,
we ed s t op , Typar , Weed Ba r r ie r , WeedB loc k an d ncon , Fa b r i c s o r
pe r fo r a t ed fi lm s th at re str i ct we e d r oo t pe netr a t i on should
p rov id e gr e a t e r weed co n t ro l than ma t e r ia ls all owing g rea te r r o ot
pe n e t r a t ion.
l We e d Sc ientist and Nur s ery Sp e c ia l i s t , ve , Pol y t ech. Ins t. and
St a te Un i v . , Hampt o n Roads Ag . Exp , Sta ., Vi rg in ia Be ach , VA
23 455 .

73
RESPONSES OF FIELD AND CONTAINER GROWNILEX . RHODODENDRON,
TAXUS, AND CRAPE MYRTLE TO BEi'a'AZON
J . Ray Frank l and C. E. Be s t e 2
ABSTRACT
Fie ld a nd conta in e r weed cont r ol exp e ri me n t s wer e condu c t ed d uri ng
1990 usi ng one or two a ppli cati ons of benta zon at 1.1 kg /h a to field
grown 'Hell er 's ' Jap an e s e holly (Ilex cr enat .a ' He l l e r ! ' ) and Roseum
El ega ns rh ododen dr on (Rho dode nd roncatawb len s e cv Rose um El e gans) . The
same r a t e s of be n tazo n a nd a 2 . 2 kg/ha r at e were als o appl i ed to
conta in e r -g rown 'Hi c ks' yew (Tax us x media Reh d , •Hi c k s ! l ' ). ' Ru br a '
c rape myrt le ( Lagerstroem ia i nd i c a •rubra ') an d 'Hellers I Japanese holly.
No significant phytotoxicity or size reduction was o bserved o n field
grown ' He l l er s ' Japanese holly with one or two treatm ents of benta zon a t
1. 1 kg/ha . Significant phytotoxicity a nd re d uc ti o n in g r owt h was
observed on fi eld g rown 'Roseum Elegans ' rhododendron .
Phytotox i c ity t o "r ub r e ", crape myrtle , and ' Hi ck s I yew grown io.
conta ine rs was o.ot appa rent wi t h bentazon t re atm ents up to 2 .2 kg/ha but
a s ign i f ican t s iz e reducti on was observe d at th e end of t he g rowin g
s eason. Phy t ot ox ic i t y t o ' He l l e r s' J a panese holl y g ro wn i n cont a in er s
wa s s ig ni f i c a nt and a s ig n if i c a n t redu ction in pl an t si z e was obs erv ed .
One app lica ti on of ben t az on at 1. 1 kg / ha i n field pl ots co n tro l l ed yellow
nu t s ed g e (Cy pe rus esculentus L.) 90% while t wo tr e a t me n t s a t 1.1 kg/ha
contro lled 98 % of the yellow nu t ae dge ,
l Wee d Sci en ti s t . USDA-ARS. Ft . Detrick . Bldg . 1301. Fr ed e r i c k , HD 2170 2 .
2Assoc . Prof . • Uni versity of Ma r yl a nd. LESREe/Salisbury Fa c il i t y .
Salisbury . MD 2180 1

74
SELeCTIVI TY OF CLOPYRALID I N WOODYORNAMENTALS
J .P .
Ah r e ns l
ABSTRACT
Sev e ra l f i eld an d o n e c o n tai n e r exper im ent wer e conducted
from 1985 t o 19 90 wi th c lopy r ali d spr a yed o ve r the t op o r on th e
basal foliage of a n urab e r of wo o d y o r namenta ls . Ra t es of
application ranged from 0.14 to 0.56 kg{ ha i n 270 L/ha .
Bi rd vetch (V i e ia ~~ L .) an d h o r s e v e e d (Co ny z a
can aden s is (L. ) Cr o n q • ros ettes ....e r e c o n t ro l le d at 0 . 14 k g/ ha .
Howe ver , in th e summe r , 0 . 28 k g / h a was ne eded t o ki ll ho r s e v e e d
ove r 20 em tal l. Cont ro l of mugwo rt (A rtem e sia vul g ar i s L.) wa s
over 90% with clopyral1d at 0.56 k g / ha i n J une o r Jul y . Ho weve r,
the best cont rol (ove r 95 %) was with sp li t a p p lic a ti o n s a t 0 .14
o r 0 .28 k g/ha in Jun e or J ul y pl us Sep te mbe r.
Ornamenta ls that to l e rated the sing le or dou ble ap plic ati ons
of clopyralid vt t hou t visible inj u ry included ye'ol (~
~~:~~~:~~ ) ~e~~~~~~:i j ~ n ~ ~~~r ( ~~:~ o~~~: j ~o ~~~~~~:~~; i : I ~; ~~: 'Da r k
c o mpac t a) and whi te spr u c e (P i cea g l auca) . Eas t e r n hemlock
(Ts ug a ca nade n sis) , Do u gl a s fir (Ps eudot su ga me na t e e Ld ) and
fr a s e r fi r (Abies f r aser O developed c ur led needles on th e
youngest g r ov t h of some plants , especially a t 0. 56 k g / h a but t h e
Ln j u r y was t olerable and g r owt h and vigor were not vi sib l y
affec ted . Tempora ry tip chlo rosis also vas obse r ved i n t h e
hemlock . The a d d iti on o f X-77 s u rfact an t a t 0 .2 5% v / v d id n ot
affect woody plant r e s p on s e o r t h e con t ro l of mugw ort
ho r s e vee d •
In another experim ent tende r grow th of Hic k s ye 'ol (Ta x us
med ia hicksi) exhibited s lig h t to mode rate t wi s t i n g fr o m an
Au gus t a p plica t io n o f cl o py ra li d a t 0 .1 5 t o 0 . 4 5 k g /ha ,
indicating tha t ye w cul t iva r s may var y i n their t ol eran c e. Ot h er
activel y growing woody o rnam en tal s t ha t wer e not i n jur e d by
clopyrali d at 0.14 to 0.56 kg/ha included field -grow n Juni peru s
virginian a 'Skyrock et' , and c onta i ner -grown Mug ho pine (Pinus
.!!!.!!.K2mugh us) and Rho dodend ro n 'Ro s e um El e gan s' . Comb i ni ng
cl opyr alid wi t h o xy fl uo r fe n , sethoxyd irn o r is oxaben did not
affect inju ry to Easte r n hemlock, ' Sk y r o c k e t ' j u n i pe r or to Tax u s
cuspidata densiformis in the field .
The effectiveness of clopyralid in contro lling tr o ub l e s o me
weeds in t h e As t er ac e o e and Fa b ac e a e families and it s appar e n t
safe ty in many wo od y o r name ntals coul d make i t a valuab l e fu t u re
tool in the la ndscape and nur sery ind u stries.
Plant Phy siologist , The Connecticut Agric ultural Experi ment
S t a ti o n , Valley Laboratory , Windsor , CT 06095 .

75
COMMON GROUNDSEL INTERFERENCE IN
CONTAINER~GROWN NURSERY CROPS
Susan M. Mulgrew 1
ABSTRACT
Common groundse l (Senecio vulgaris L) is frequently fou nd infesting nursery crops in the
Northeast. II is considered part icularly troublesome in ccotamer-q rown crops because it begins
growing in containers stored in overwintering houses, prio r 10 spring applications of
preemergence herbicid es. Common grou ndsel also germinates in late summer and early autumn ,
when many spring-applied preemergence herbicides are no longer active. Altho ugh commo n
groundsel is frequentl y found In Northeast nurseries. its affec t on the growth of nursery crops has
nOIbeen established.
Common gro undsel interferen ce was determined in container-grown boxwood (Buxus
sempervirens L. 'Wintergreen'), euonymus [a variegated sport of Euonymus ton unet radicans
(Seibold ex Mlq,) Rehd.), and Sargent juniper (Juniperus cmnensts sargent ii A. Henry). Bare-root
liners of each species were planted in 3.8 Land 7.5 L contai ners between February 23, 1990 and
March 1, 1990. Three-week-old groundsel seedlings were transplanted into the containers at
rates of 0, 1, 2, 3, and 4 weeds/con tainer on February 26 (euonymus and juniper) and February
28 (boxwood). Any additiona l weeds that germinated in the containers dur ing the experiment
were removed by hand. Nursery crop growth index «height + width .1 + width .2)/3) , where
width.1 and width .2 are measurements taken in north-south and east-west direct ions, was used to
determine the effect of groundsel interference on the growt h of the nursery crops . Growth
indices were measured on February 28 (0 weeks) and 2, 4, and 6 weeks after transplanti ng (WAT)
the groundsel seedlings . Since the groundsel plants had set seed and some had begun to
senesee by 6 WAT, the experiment was terminated after the 6 WAT measurement. The
experiment was condu cted In a polyhouse where the temperatures were maintained between 22"C
(day) and 12·C (night).
Common groundsel did not interfe re with the growth of euonymus , but reduced the
growth of boxwood 2 through 6 WAT. The decrease in boxwood growth was linear at 4 and 6
WAT (Table 1). There was also a linear decrease In juniper growth at 4 and 6 WAT (Table 2).
'Assistant Professor of Nursery Crops, Dept. of Plant and Soil Sciences, University of
Massachusetts, Amherst, MA 0 1003.

76
Table 1
Effect 01 common groundsel and contai ner size on the growth Index of 'Wintergreen '
boxwood .
mean growth index (em)"
Treatmen t o WAr'" 2 WAT 4 WAT 6WAT
weeoe/cco tatner
0 10.1 11.3 14.9 16. 1
1 10.9 12.5 16.1 17.5
2 10.5 11 .8 14.6 15.4
3 10.1 1 1.1 13.8 15.2
4 10.6 11.6 14.5 15.0
Treatme nt significance
Weeds
NS'
Linear
NS
Ouadrat ic NS NS NS
Container size NS NS
'Gr owt h Inde x is de term ined by (he ight • widlh .l • wi(1th.2)/ 3 Width .l and widlh .2 are mll8surament s taken In nortn.
south and east-weS1 direction s
~AT • weeks after transplanhllg common groundsel seedl ing s into ocnta lners.

77
SEL ECTIVITY OF SULFONYL UREA HERBI CI DES I N WOODYORNAMENTALS
John F . Ah r e ns!
ABSTRACT
The po tent i al for herbi cide l eachi ng t o g r o u n d water le d us
t o ev alu ate l o w rate s u lf o ny l urea herbicides f or selec t i v ity i n
....c o dy o r n am e nta ls . In o n e exp e r i me n t c h l o rim uron 9 , 18 an d 36
g /ha, thifen sulfuro n 17 .5, 3 5 a n d 7 0 g/ h a a n d CGA- 13687 2 20 . 4 0
a nd 8 0 g/ ha were sp r a yed o ve r o r namen ta l s in 270 L/ ha a month
af ter pl ant in g and r e a p p li e d in May f or t v o mo r e s e a so ns . All
wer e tank-m ixed with o r y ae Lt n 1.12 kg/ h a t o control a n n ua l
grasses . The plants included arb orvitae (Th uja oc c ide n tali s
' Li t t l e Gi a nt ') ye w (Tax us c uspi date d e n s t Eo r sri s ) , Eas te r n
hemlock (Ts ug a ca nadensis) , Rhododen dron 'Nov a Ze mbl a ' an d
Co t o n e as t e r s a l i c i f o l i a 'Re pandens .'
Th e su lf on yl urea herb i ci des gave po s teme rg e nce a nd s h ort
pr e erae r g enc e control o f cert ain bro a d l e af we e d s, n ot abl y c or n
chamo mil e (Anthemis e r ve ns t s L.) but resi d u a l c o n t rol 2 t o 3
mont h s a f t e r weed i ng, especia lly wi th t hi f en su lfuron o f t e n was
be t ter th a n wi th or y z al i n al on e .
Chlor im u ro n a nd CGA- 136872 at a l l rate s injured co ton eas ter
exces sive ly but t h Lf e n s u Lf u r on injury was te mporar y. Arborvitae
an d yew o f t e n ex h i b i t ed early s e a s o n c h Lc r c s Ls ....i t h re c over y f r o e
the sulfonyl u r e e s wh er e as heml ock was unaf f e cted b y a ny
t r e a t ae n t . Only CGA-136 872 at 80 glha si gnificantl y Ln j u r ed
rhodod endron with e a r Ly vein al ch Lo r o e t s and Lnc r e a s ed eo r t e t t t y .
Chlo r im u ro n and CGA-136 872 we r e eva lua ted in o t he r
e x perime nt s . CGA- 136872 at 40 o r 80 g l h a + X-77 0 .2 5 % v l v in
ap r t I e u p p r e s e e d field b o r ee t a I 1 (Equ ise tum ~ L.) f o r 2
month s a n d quackgras s (~ . e pe n s ( L .) Be a u v ; ) f o r 3 months
with no i n j u ry t o d or mant Ea s t e r n wh it e pine (Pinus st robus) .
Ch lo rim u r o n a t; 9 to 36 glh a i n Ju ne suppr essed field h o r s et a il
fo r 1 mon t h wi t h o ut inj ury to a c t ive ly gr o win g white pin e .
Chlori muron a t 9 o r 18 g/ ha i n Dc t ob e r co nt ro ll ed seedl i ng
hc r eevee d (Cooy za can ad ensi s ( L.) Cr o nq.) a nd in j u red newl y
pla nte d b ut no t establi shed Den a i f o r mi s yew . Chlor i muro n a t 9 o r
18 g/ ha + X- 7 7 at 0.25% vl v a l s o contr o lled s e e d li ngs of pi gweed
(Amaranthus .!:!..E....E..) and h o r s ewe e d i n July with no i n j u r y to fr a s e r
fir (Abies f r e ee r t ) . Contain e r c-g r o wn mu g ho p ine ( Pin us ~
mughus) and Rh o do d e n d ro n 'R o seum Elega ns' v e r e u n af fecte d by
chlori muro n a t 9 to 36 g/ h a .
It a p pe a r s that th ese h erb icide s ca n b e sa f e ly u se d in a
number o f woody ornament a ls . Cb l c r t mu r o n an d CGA- 136B 72 des e r ve
fur ther ev aluation.
Plan t Physi o log ist , The Connec ti cu t Agr i cu l tural Exp e r i me n t
Stat i on , Val le y Laborator y , Wind s or , CT 0609 5 .

78
TOLERANCE OFDIRECT-SEEDED CUTFLOWERS TOPREEMERGF..NCE
HERBICIDES
A.F. Senesac ll and J.e.Neal2
ABSTRACT
Field grown cutflowers are an increasinglyimportantand profitable component of
manyroadsidemark et operationsinNew York. Mostof the preemergenceherbicides
registered for cutflowers are appliedpostemergenceto transplants,but there is interest in
direct seeding some of the most popular species. However, there is very little informa tion
about plant tolerance of the more commonly used herbicides with this method of planting.
Two field studies were conducted in 1989 and 1990 at the Long Island Horticultural
Research Laboratory to examine the tolerance of Zinnia~ and Celosia

79
PREEMERGENCE HERBICIDES ON CONT AlNER G ROWN NURSE R Y STOC K
Larry J. Kuhns and Joanne E. Looset/
ABSTRAcr
Herbi cides used to contro l weeds in container grown orname ntal s mus t overcome three
obstacles. Most of the media usedtoda y have a very high organi c man er content, the plant s are
frequently irrigated , and uniform distribution of granul ar materials is difficult to obtain in the
confined areas common to containe r produ ction nurserie s. The herbicide formul ation s used in this
study were desi gned to overcome one or more of these obstac les. Metolachlor + simazin e in a 4: I
ratio and 5% gran ular form ulat ion was applied at 2.2. 4.4, and 8.8 kg ai/ha. Three 2% granular
formulations of oxa dia zon were applied at 2.2 and 4.4 kg ai/ha. They were the standard Ronstar 7J
fennulation with an 18/40 partic le size. on a Biodac carri er with an 18/40 particle size. and on a
Biodac carrier with a IfV30 panicle size. A ready-to -use 1% microe ncaps ulated form ulation of
triflurali n was applied throug h a hose and garden spray nozzle at 2.2 and 4.4 kg ai/ha. G ran ular
materials were spread in individual pots by hand.
Eac h treatment was applied to six species of newly potted roo ted cuttings of woody
ornamental shrubs: yellcwrwlg dogwood ~~L.), borde r fors yth ia~X
~ Zab.), Cascade azalea (Rhododendron spp.) , Van houtte spirea (Spiraea X
Vanhouttei[C. Briot (Zab.)]), dwarf Korean lilac

80
Both rates and all form ulation s of oxadiazon provided more than 50% control of grasses at
time 1, and all but the low rate of the 16130Biodac formu lation provided total control at time 2.
At time I, at the low rate of application, the conunerc ial fonnu lation of oxadiazo n (Ronstar)
provided better control of the purslane than theoxadiazon on the Biodac carrier. At the higher rate
of application the control of thepurslane was better , but there was no difference between
formul ations. At rime 2, all treatm ents prov ided excellent control of thepurslane except the 18/40
mesh Biodac, which pro vided abou t 50% control. At time 1 and time 2 the high rate of the
commercial formulation provided better control of the other broad leaved weeds than the low race
or either rate of the other formula tions.
Both rates of trifluralin pro vided exce llent control of purslane throughout the study. Its
co ntrol af the oilier broadleaved weeds was excell ent at timel, and very good 14 weeks. Both
rates provided excellent co ntrol at time 1. At time 2 thehigh rate provided total control and the low
rate no control.
The lilac could not be rated for injury because of generally poor, erratic growth . Non e of
the herbicides except nifluralin caused any visual injury symptoms on any of the plants. At time 1,
some plan ts of all species treated with nifluralin had slightly chlorotic. burned , or curled leaves. In
almost all case s new gro wth developed beyond the injured leaves, making the injury less
noticeabl e. Several of the treated dogwoods also seemed to be rooting poorly, as they were loose
in the pot At time 2 there were no visual symptoms of inj ury to any of the plants . Howe ver, an
exami natio n of the root systems of severa l do gwood and forsythi a plants from each treatme nt
showed the root systems of the triflurali n treated plants were smaller than those from the other
treatments. Appare ntly there was enough water and fertilizer applied to support nonnal top grow th
even with a redu ced roo t system .

Table 1. Weedcontrolprovided by preemergenceherbicides appliedto six speciesof containergrown
ornamentals. The numbersrepresentthe averageweedcountpercontainer. Herbicides were
appliedinmid- tolate June andcountsweremade 6 and14 weeksafterthe last application. All
weedswereremoved from the potsat the first ratingperiod.
Other
~ ~ QImes
~ Rate (kgailHa) l1mU :J:i!lU Ii!m..l :Ii!M.l Iimtl IiInti
Control 0.0 3.0 0.9 0.9 2.9 1.5 0.3
Metolachlor+ Simazine 1.7 + 0.4 2.0 1.3 0.5 1.4 0.4 0.1
Metolachlor+ Simazine 3.5 + 0.9 1.9 l.l 0.2 1.2 0.1 0.1
Metolachlor+ Simazine 7.0 + 1.8 1.6 0.6 0.3 1.5 0.1 0.1
Oxadiawn (Ronstar) 18/40 2.2 0.7 0.2 0.5 0.9 0.7 0.0
Oxadiawn (Ron star) 18/40 4.4 0.5 0.1 0.3 0.4 0.7 0.0
Oxadiazon(Biodac) 18/40 2.2 1.3 0.5 0.5 1.3 0.7 0.0
Oxadiazon(Biodac)18/40 4.4 0.5 0.2 0.5 0.7 0.6 0.0
Oxadiawn (Biodac)16/30 2.2 1.1 0.1 0.6 2.4 0.7 0. 1
Oxadiawn (Biodac)16130 4.4 0.6 0.2 0.5 0.7 0.7 0.0
Trifluralin 2.2 0.2 0. 1 0.1 0.6 0.1 0.3
Trifluralin 4.4 0.1 0.0 0.1 0.4 0.0 0.0
~

83
The Effect of Nutrient Availability on Competiti on between Velvetlea! and Kidney Beans
E. T. Maynard and H. C. Wien 1
ABSTRAC T
A field experiment was initiated in 1989 to dete rmin e the re lationship be twe en
velvetleaf CAhutilan~ Medik.) density and yield of kidn ey be ans (p hase olus
~ L. 'Redkloud ') . Beans were planted in the secon d week of June , with 21, 28,
and 35 kg/ha of N, P, and K, respectively, banded on one side of the be an row, and
0, I, 4, 16 or 64 velvetleaf/m ' sown close to the row on the other side. Velvetleaf
growth was not vigorous , and bean yield showe d only a slight response to velvetleaf
density: a linear regression predicted that 33 velvetleaf/ m' would decreas e bean yield
by 5%. In a different expe riment , velvetleaf show ed a ten-fold increase in mean dry
weight pe r plant in respo nse to a nearby fertilizer band. This obse rvation, together
with soil test results indicating low leve ls of P and K, suggested that velvetleaf would
be more competitive if given access to more nutrients . In 1990 tre atments designed
to provide velvetleaf with more nutrients were adde d to the experiment. In these
-+F" trea tments , in addition to banding NPK as in 1989, 44 and 83 kg/h a of P and K,
respe ctively, were broadcast and incorpor ated prior to planting, and velvetle ai was
sown on the same side of the row as the fertilizer band. Other tre atments (-F) we re
unchanged from 1989. Early-emerging velvetl eaf in the +F plots produced more
than ten times as much dry weight by mid·Augus t as in -F plots . In the +F plots
only, bean dry we ight in August showed a slight linear decre ase with increasing
velvetIeaf dens ity. When grown in the greenhouse at three levels of P, sole
velvetIeaf showe d a proportion ately grea ter increase in dry weight and height in
response to P than did sole beans. Field and greenhouse resul ts both sugg est that
the amount of fertilizer available to velvetIeaf and to be ans is important in
determining the degree to which velvetleaf will interfere with bean growth .
'Graduate Stude nt and Assoc . Prof., Dept. of Fruit and Vegetab le Science , Cornell
University, Ithaca, NY 14853

SHARPSHOOTER
84
EFFICACY IN COVER CROP BURN-DOWN AND
POTATO VINE-KILL
T. A. Blomgren and R.R . Betlinder '
ABSTRACT
Potassium salts of medium chain length, saturated fatty acids are being developed as a
herbicide under the trade name Sharps hooter. It is nonselect ive, and works on contact by
disrupting cell membrane s. Action is rapid, often prog ressing fro m water-soaking to necrosis
of affected tissue within a few hours. Trans location appears not to occur. The primary
focus of this study was to determi ne how Sharpshooter compared with currently used
nonselective herbicides in cover crop regulation. A preliminary greenhouse study conducted
in the winter of 1989 indicated that, at 4 and 8% (v/v) rates, Sharpshooter could provide
effective (>70 %) control of hairy vetch CYi.tiaYil.J..Qsa L.) and rye ~~ L.) but
performed inadequ ately « 70%) with red clover CIr:i.fuI.i.ym~ L.) and red fescue
~ mb.raL. ). In the spring of 1990 Sharpshooter efficacy was eval uated in the field.
Six herbicide treatments were applied to 2 stages of rye (46cm and 76cm) . The treatments
included 1) an untreated check , 2) paraquat (.56 kg a .Uha), 3) glyphosate (1 .68 kg a.Uha) ,
4)Sharpshooter-8 % (v/v), 5) Sharpshooter-12% and 6) Sharpshoote r-8 % applied twice. Both
glyphosate and paraquat performed better than all Sharpshooter treat ments . Glyphosate
provided com plete control and paraqua t was more than 85 % effective at both stages of rye
growth. At the earlier stage, 52, 65 and 78% control of rye was obtained with 8, 12 and the
duplicated 8% applications of Sharpshoo ter, respectively. At the later stage there was no
diffe rence in control regard less of Sharps hooter rate; both provided approximately 75 %
control. Two application s of Sharpshooter (8+ 8%) did not provide bette r control at the later
stage than did the single application. A second study was condu cted in September of 1990 to
compare Sharpshoo ter to paraquat for potato vine-kill. Sharpshooter was applied at 8 and
12 % (v/v) rates and paraquat was applied at .56 kg a.U ha. All 3 trea tments provided more
than 97 % control, suggesting that Sharpshooter may be effective as a pota to desiccant.
1 Grad . Student and Assoc. Pro fessor, Department of Fru it and Vegetable Science , cornell
Unive rsity, Ithaca NY 14853.

85
WEED CONTROL IN POTATOES WITH DPX-E9636, GLUPHOSINATE
AND PARAQUAT
Gregory A Porter and Jonathan A Sisson'
ABSTRACf
Broadleaved weeds and quackgrass (Agropyro n Teoen s L) simul taneo usly infest
many fields in the Northeas t. While several herbicides provide good control of most
broadJeaved weeds in Maine potato (Sola num h lberosu ffi L.) fields, effective grass
herbicides are limited. Herbicides are needed which allow consistent quackgrass control,
preferably at the same time that broad leaved weeds are being controlled.
DPX·E9636, gluphosinat e, and paraquat were applied alon e or in combinatio n
with metri buzin or Iinuron in 1990 field experiments at Presqu e Isle, Maine . Weed
pressure consisted of musta rd spp. (prim arily Brassica campest ris L.), lambsquarters
(Chenopo dium album L ) and quackgrass at the following average den sities: 244, 28 and
94 per m 2 , respectively. The pot ato variety used was 'Katahdin' . In one experiment,
DPX·E9636 was evaluated alone as a postemergence (POST) treatment at rates ranging
from 0.018 to 0.069 kg ai ha' or as a POST tank-mix with metr ibuzin (0.28 to 0.42 kg ai
ha'). Additional treatments provided an evalua tion of DPX-E9636 as a preemergence
(PE) tank-mix with linuron. In a second experiment~ gluph?s inate was applied a ~ .
groundcrack (GCK) at two rates (0.56 and 0.84 kg at ha" eithe r alo ne or tank-mixed With
0.56 kg ai ha'! metribuzin. Additiona l treatments include d paraquat (0.28 kg ai ha" )
applied at GCK either alone or with 0.56 kg ai ba'' metribuzin .
In the first experimen t, DPX·E9636 resulted in slight chlorosis and leaf curling of
the potato foliage at 14 days after treatment (DAT), but not at 36 DAT. Injury
increased significantly with application rate. All metribuzin and Iinuron treatments
provided excellent broadleaved weed control. DPX -E9636 (POST) provided fair mustard
control by 13 DAT and excellent contro l by 36 DAT. The lowest DPX ·E9636 rate
provided fair lambsquarters contr ol while the rema ining rate s pro vided good controL
DPX-E9636 (POST) provided excellent quackgrass control by 36 DAT regar dless of rate ;
however, PE app lications were not effective . Treatments whicb effectively contro lled
quackgrass genera lly had significantly higher yields than those which did not. In the
second experiment , GC K treatme nts containing gluphosinate or para qua t resulte d in
significant leafburn of potato. Injury symptoms for gluphosinate were more severe and
long lasting. All trea tments provided good to excellent season-long mustard con trol
except for gluphosinate without me tribuzin. The highe r glupb osinat e rat e provided good
quac kgrass control by 10 DAT. Tank-mixes with metribuzin improved mustard and
quackgrass control by both paraquat and gluphosi nate. Alth ough all gluphosinate
treatments appeared to decrease yields, only the 0.84 kg ai ha" treatments were
significantly lower than the handweeded check.
'Asst . Professo r and Research Assoc., Dep t. of Plant, Soil and Environme ntal Sciences,
University of Maine, Orono. ME 04469.

86
TOlERANCE
OF OF CAULIFLOWER AND BROCCOU TO MEfOLACHLOR
A.F. Senesecl/ ,R.R. Bellinder2 D. Wilcox-Lee3 and R.W. Wallace 4
ABSTRACT
Metolachlor, a widely used preemergence herbicide, could be a useful tool for weed
control in crucifers. Early season plant stunting has been observed in some crucifers with
high rates of metolachlor. Although actual yield loss may not occur, a delay in harvest
maturity can be a result of this stunting.
Field studies were conducted ove r a three year periodat two locations: Riverhead.
L.I, and Freeville, New York to examine the effect that post-transpla nt applications of
me tolac hlor have on total yield and harves t maturity of ca uliflowe rCBrassica oleracea italjca
L. ) and broccoli (BrassieR oJeracea botD'tjs L.) cultivars. On Long Island, cauliflower
cultivars 'Snow Crown'(198S-1990) and 'Snowball Imperial'( 1988} and 'Andes' (l 989­
1990) were transplant ed bare root in the summer into Riverhead Sandy Loam. Me tclachlor
was applied 48 hours postplant and irrigated immediat ely. At f reeville, cauliflower 'Snow
Crown' and 'Andes'(1989-1990) and broccoli 'Emperor ' and Green Co met' (1989-199 0)
were sown in transplant cells in the greenhous e and planted in the spring in Eel silt loam .
On Lo ng Island, both cultivars were harvested over a period of several weeks in the
fall. Curd weight of either cultivar in any of the three years was not significantly reduced
by metolachlorrates of up to 4.48 kglha In 1988 and 1990, the time to harves t maturity
was also not adversely affected. In 1989, the wettes t of the three years, the time to
maturity was significantly delayed by mero lachlor rates of 1.68 kgtha or more .
At Freeville , both cauliflower and broccoli were harvested in a more concentrated
time period during the summer. Neither total yield nor the time to maturity were
significant ly affected by metolachlor Tatesranging from 1.68 to 4.48 kglha.
At both locations , some early season plant stunting was observed, especial ly at the
higher rates. However in only one year and at one site, 1989 on Long Island, was the
plant stunting severe enough to result in a harvest delay. It appears from the results of
these studies that cauliflower and broccoli can tolerate metolachlor fairly well under a
variety of condi tions, but that some plant stunting and harvest delay can occur under very
wet soil conditions.
IIWeed Science Specialis t, Cornell Coope rative Extension, Long Island Horti cultural
Research Laboratory, Riverhead, New York 11901 .
21Associate Professor, Dept. of Fruit and Vege table Scie nce, Corne ll University, Ithaca,
NY 14853
31Associate Professor, Dept of Fruit and Vegetable Scie nce, Cornell University, Long
Island Horticultural Research Laboratory, Riverhead , New York 1190 1.
4/Graduate Research Asst. Dept of Fruit and Vegetable Science , Cornell Univers ity,
Ithaca, NY 14853

87
clo pyralid and pyri da t e f or postemerqenc e
Br oa diea.! Weed Contro l in Crucifers
Russell W. Wall ace a nd Rob i n R. Be Ll Ln d ez-!
AB STRA CT
Field studies wer e c ondu c t e d in 1990 at th e Ve ge t a b l e crops
Rese ar ch Farm i n Fr e e v i l le , NY, to d e te rm i ne the eff ects of
po s t eme rg e nce t r ea t men t s of c lo pyra l i d and pyridate on weed
c on t r ol , c r op inju ry , and y ie l d in ca bba g e (Brassica a le ra c e a
var. cap i t ata) , brocc o l i (~ aleracea v a x . ~) and
cau liflo wer (Br as s ica al era cea va r . ~) . All p lo ts we r e
t r e a t e d wi th triflura lin (0 .8 4 kg ai / hal ap pl ie d pr epl a nt
incorporat e d for gr a s s con t roL In cabbage , cl op yr al id (0 .2 1 a nd
0 . 4 2 kg a i /ha l a n d p yr idate (0.50 and L Oa k g ai / ha l we r e ap p lied
a lo ne and tan k - mixed at J (Epo s t) and 5 (Lp os t ) weeks af te r
tran splanti ng (May 30 ) . Four ca bbag e cu lt i vars we re e va luat ed
a nd i nc l u d ed: Tastie, Super Dan e , Br avo , an d Hinova. In
br occoli ( Emp e ro r and Gr een Comet) a nd caul if lowe r (S now Cr own
and And e s) , b o t h herb ic ide s we re a pp lied a lo n e and in com bi n a t io n
at t h e l ower rates , but on l y a t t h e earl i er ti ming . Br o a dlea f
wee d s pe c i e s i n t h e e xp e r ime nta l si t e s incl uded re d r oo t pigw eed
(Arna r a nt hus re trof lex u s L . ) , c ommon lamb squarters (Ch en opodium
s.l.Qym L .) , ha ir y ga l i n s og a ( ~tiJ..i.s:tA (Raf .) Blake , a nd
c ommon pur s lane (~ o ler acea L .). In t he c a bb a g e s tudy ,
c ont r o l of re dr oo t p i gwe e d wa s 95% or b ett er wi t h bo t h herbicid es
r e g a r d l e s s of rate or t i min g . Tank - mixed t rea t me n t s also gav e
excel len t c on t r o L I n t h e br o c c oli an d cau l i fl owe r s tu d i es ,
gr e a t e r th an 9 5 % contro l of common l ambs qu ar t ers , ha i r y g alinso g a
a nd co mmon pur sla ne wa s also o bse rv e d. Injur y f rom pyr i da t e wa s
obs erve d a s chl or os is of t r e a t ed l ea ves, while no v i s u a l i nj u r y
resu lted f ro m cl op yral id. Al l thre e crucife rs t e sted we r e
sens it i ve to pyri d a te , wi th cab bag e being le as t a nd br occ oli the
mos t sensi ti v e . Howe v e r, inj u ry sym p t oms gen e ra l l y d e c re as e d
afte r 3 we e k s . I n c abba ge , Ta s t i e wa s mos t su s c e p t i b l e t o
inju r y , but the hi gh r ate o f py ri d a t e a p pl i ed Epost ca used the
mos t injury t o al l cul t iv ar s . wit h ca ul i fl ower and br oc co li,
i nj ury was gr e a t e s t i n And es an d Gr een Comet, respecti v ely .
In j ur y f ro m pyr ida t e did no t corre la t e with r e duce d yields i n
th r e e ou t of t h e f ou r c abb a g e c u l t i va r s . Yields i n al l cu lt ivar s
ex c ep t Hi no v a we re not red u c e d . Hi nova , h owev e r , wa s th e lates t
matur ing cu l ti var, and t hi s ma y h a v e p l a y e d a r o l e in th e yi e l d
res pon s e t o t h e h er b icide tr e at me nts . In c a u l i f l owe r a nd
broccoli, no sig ni f ican t r e du ct i ons in y ie ld oc c ur r ed wi t h an y
pos te mergen ce h erbicide tr e a t ment .
I Res earch Tech . and Asso c . pr o f e s s or , Dept . of Fru i t an d
ve g e t a b l e Science, Co rnell Univ e r s i t y , Ith ac a , NY 1485 3.

88
Potential Diphenyleth er Herb icides
for Use in Snap Beans
R.R. Bellinder and R.W . Wallace l
Abstract
The loss of dinoseb and chlorambe n has necessitated the development of alternative methods
of controllin g broadleaf weeds in snap beans~~ L.). The objec tive of this
research was to evaluate preemergence (PRE) and postemergence low dose applications of
acifluorfen , fomesafen and Jactofen on crop phytotoxicity and weed control in snap beans (var .
'Labrador'). The herbicides were applied at different rates and timings based on known
potential phytotoxicities. Rates were : acifluorfen 0.07 to 0.56 kg ailha PRE and at the ls t
trifoliate; fomesafen 0.28 to 0.5 6 kg ailha PRE , lst trifoliate, and prebloo m; and lactofen 0.14
to 0.56 kg ailha PRE and at ground crack. Metolachlor (1.7 kg ailha PRE) was applied to the
experimental site and the study was irrigated (2.5cm) after both the PRE and the ground crack
timings. Greater than 25 % crop injury occurred when acifIuorfen was applied at 0.5 6 kg PRE
and at 0. 42 and 0.56 kg at the 1st trifoliate. Fomesafen injury . general ly half that observed with
acifIuorfen , was eviden t at 0.56 and 0.42 kg applied PRE and at the 1st trifolia te, respectively.
Stands were significantl y reduced in the lactofe n ground crack treatments. Lactofen injury ( 19­
63 %) at harves t, occurred with 0.56 kg PRE and with 0.14 , 0.2 8 and 0.56 kg at ground crack.
In spite of partial control resulting from the metolachlo r application, all preemerge nce treat ments
provided season-long control of redroct pigweed ~~ L. ) and common
lambsquarte rs (Chenopodium al.!mm. L.). Control of wild buckwheat~~
L. ) was excellent with fomesafen at all rates and timing s. Applied posteme rgence , 0.07 kg
(acifluorfe n), 0.14 kg (lactofen) , and 0.2 8 kg (fomesafen) effectively controlled redroot pigweed.
Postemergence control of com mon lambsquart ers and wild buckwheat required at least 0. 28 kg
of acifluorfe n for adequat e control. Desp ite evident crop injury in several cases , yields were
reduced only when acifl uorfen (0.42 , 0.56 kg) was applied at the Jst trifol iate and when lactofen
(0. 56 kg) was applied at ground crack. Yields of fomesafe n-treated beans were equal to or
greater than yields of the handweeded controls.
'Assoc. Professor and Research Tech. , Dept. of Fru it and Vegetab le Science, Cornell
University , Ithaca , NY 14853.

1 Re s earch Te ch ni c i an a nd Asso ciate Pr ofessor , De pt. of Fruit & Vegetab le
Sci enc e , Corne ll Un i versity . It h a c a. NY 148 53
89
DIVERSI TY AND SPREAD OF SEDGE WEEDS IN NEW'YORK MUCKONIONS
A. L. Westman and L . A. El le rbrock 1
ABSTRACT
Yellow nu t sedge ( Cyp e r u s ~ L . ) has re cent ly become the wor s t
we ed in New Yor k muck onions (Al l i lUD~ L.) a nd threate n s the stat e's
i ndu st r y. Pr evention of i nf e s t a t i ons i s t he on ly practical method o f
con t ro llin g t h is weed i n muck oni ons at present and in the nea r f uture .
The i mporta n c e of se ed i n spread of y e l l ow nutsedge in muc k fie lds wa s
studied by examining 1) emergence and growt h o f seed lings a nd t ube r
s prouts from co llected soil, an d 2) v i ab ility of fi el d · co ll ecte d s eeds.
Soil a nd ma t u r e s e dge i nf l o re scences were co l le c t e d Sep t embe r- October
1989 fr om New Yor k State mu c k an d mi n eral s o il fie ld s i n f e s t e d wi th
yellow nutsed ge. Tuber s p r ou t s from 10 sampled fi el d s we re g rown to
matu rit y i n t h e greenhou se. Plants f r om nine of t he fie lds i n i t i a t ed
fl or a l dev el op me n t. However , the percentage of plants ebac formed
i n f l ores ce nc e s varied among counties and among f ields with in a county ,
ra ng ing fro m 11 ' to 10 0 ' for a fi eld.
In gre enh ouse studi e s, sedge seed lings emerge d f rom sc reened soil of
t hr ee mu ck f ie l d s , one f i eld each f r om Genesee, Ora nge, a nd Oswego
Count ies (we ste r n , sou t h eastern, and ce ntra l New York r e sp e c t i v e l y ) ;
se edlings fro m two fie lds wer e gr own t o ma t u r i t y. Genesee Coun t y pla nts
produce d tubers b u t d i d not flowe r I an d we r e i de n t if ie d a s yellow
nut s e dg e . Orange Co unty pla nts were fro m soi l of an aba n done d mu ck
field. All pl ants flowered and produced seeds , bu t formed ne i t h e r
un de rground r hi zomes nor t ubers; the y were identified as t he annua l
Cyperu s odoratu s L . See ds colle ct ed from th ese Oswego an d Orange Count y
field s , and f r om a Madi son Coun t y ( ce n t r a l New Yo r k) fiel d, germinated in
th e gr e e nh ou s e . Plants f r om Oswe go County seed were a ll y e l l ow nutsedge ;
pl ants from Ora n ge Count y s e e d were y e l l ow nu tsedge a nd .Q..... odo ratus;
plan ts from Madison Cou n t y seed were ye llow nuts e dge and a pe r en n i al
species of Car e x . In addit ion, sedge seeds co llected f r om f ive muck and
t hree mineral so il fields i n 198 9 were v i ab l e af te r one ye a r dr y sto r age .
In or der t o stu dy sed ge speci es d iv ersity i n muc k fie lds, young se dge
plants were c o ll e c t e d fr om an Oswe go Coun ty onion f ie l d in 1990 and gr own
t o maturi t y i n t h e g reen h ou s e . Pl an ts co lle cted include ye l low nut s ed g e ;
Cyperus odo r a t us ; a p er e nn ial , Sciro us ped ic ellatus Fern .; and s ev e r a l
per en nial sp e c i es of ~ , mo s t o f wh i c h di d not flower the first year.
Only y e ll ow n utse dg e pr o du c ed t ube r s. The s e s t u d i e s i n d i c a t e that y e ll ow
nuts e dge i n muc k onion f i elds pr odu c es v iable s e e ds which can s urvi ve i n
th e soil . Oth er an nua l a n d perenn i al sedg es are a lso prese nt i n muc k
fi elds and pr oduc e viab l e seeds, but yel low nutse dge is t he mo s t
important sedge weed prob lem . Cur rent s tu d i e s ar e qu an tif yin g t he
viability o f yello w n u t s e dg e see ds co ll ected fr om muck f ie l ds du rin g la t e
summer and f all of 1989 and 1990.

90
PREEMERGENCE WEED CONTROL IN NEW YORK MUCK ONIONS
L.A. Elle rbrock and A. W. wee 'tma n'
ABSTRACT
On- f arm experiments a t f iv e locations in New York in 1990
involve d e va l uat i on of pendimethalin, propachlor, me to lachlo r ,
and bromixy ni l for early season weed cont rol in muck onions
(Alliu m ~ L.) . Treatments were eva luated for wee d control a nd
effec t on on ion stands, early onio n growt h , a nd bulb y ie ld .
Preemerge nc e pendimethalin at 2 .2 to 4.4 kg ha' r e du c e d sta nd,
e ar l y gr owt h, and yie ld in on e e xp er i me nt when a ppli c at i on was
f ol l owed by heavy rain a nd ve ry wet soil condit ion s. A simila r
app l ica t i on in another expe r ime nt did not cause oni on inj ury.
Ea rl y postemerge nc e pen dime th a l i n at 2.2 to 4 .4 kg ha' had li t tle
or no e f f e c t on onion grow t h , and we ed cont ro l was goo d in a ll
f i ve lo c a tions . Preeme rge nc e prop ach l or at 6 . 6 kg ne -' + ea rl y
po s t eme r ge nc e pen di me t ha li n at 2.2 kg ha" re duce d early on ion
grow t h in one of th r e e l oc a t io ns but di d not a ff e c t bul b yield .
Addi t i on of flu a zif op- p-but yl at 0 .2 kg na-' and a non ion ic
s urfa c t a nt to an early pos te mer gence a ppl i c a ti on o f pen d i rne t ha l i n
a t 2.2 kg ha'! d i d not affect oni on gr owth . Onion bulb yie ld was
not a ffect e d by ear ly posternerg enc e metolachlor a t 2 .2 kg ha - t in
two l oc ati ons , but metolachl or a t 3 .3 kg ha -I di d red uc e yie ld in
one loca tion , whereas weed con trol was only fair. onion stands,
early growth, and bulb yield were no t affected by e a rl y
pos t e merg e nce applications of from 0.3 to 0.4 kg ha -I bromoxyni l
no r by ea r l y postemergence app lica tions of from 0.1 to 0.4 kg ha'
bromox ynil + pendamethalin at 2.2 kg ha ", Early pos temergence
applications of bromoxynil at relatively low rat e s gave variable
leve ls of weed control. Prostrate spurge control was excellent
i n one c a s e , whereas control of sh e pher ds pur s e a nd other mustard
spec ies was poor.
As sociate Professor a nd Research Techni cian, Depa rtment
of Fruit and Vegetable Science , Corne l l Unive rsity,
It ha c a , NY 14853

91
l1IE EFFECT OF LIGHT INTENSITY AND WAVELENGTIfTRANSHIITANCE OF PlAST IC
KULCHES ON YEu..oW NUTSEDGE
P . E . Neary
a nd B.A . Ha je k l
ABSTRACT
Obs ervations in the fiel d hav e indi cated t ha t yello w nut s edge i s capable of
pen etrat i ng bla ck pla st i c mulc h . Onc e abov e t he mulc h th e nu t s ed g e can ben efi t
fr om the s oil war mi ng p r ovid ed by t he mulch a nd f ul l su nli gh t . d e pe ndi ng on th e
c r op c an opy . Yel l ow nu tsed ge do e s not re a dily pen etrat e pla st ic mulch e s th a t
t r ansm it l i ght , i nc lud i n g cl e ar pl as t ic mul c h . I t is hyp o the s i z ed t h a t mulc he s
t ha t t r a ns mi t rela ti vel y s mal l amounts of l i gh t c an su ppres s ye l low n u t sedge by
no t allowing it: t o penetrat e the mul ch and gr ow und er f ul l su nl ig ht . The
o bj ective of t h e 19 90 e xperi men ts wa s to d e t e rmi n e t he eff e ct of 10,,", l igh t
tra n smit t i n g de gra da ble mulc hes and a wa ve l en g t h sel e ctiv e mul ch , th a t tr a n smit s
app r ox ima te ly 50% of t h e s ol a r i n f rar e d ra d i a tion whil e allow in g onl y 20X of
the ph o t os yn t h eti c all y ac t ive ra dia ti on (PAR), on t h e g rowth o f ye l low nu t s ed ge .
The field experimen t included t wo d if f e r e n t cro ps t o d e t erm in e t h e ef f e c t of
crop canopy on potential nutsed g e suppres sion. Th e re s ul t s of t h e g ree nh ous e
study ind icate d th a t pl a st i c mul c h es t r a ns mi t tin g r e l a ti v el y s ma l l a moun t s of
lig h t su p pre sse d y e llow nu t s ed ge gro wt h an d t ub e riz a t i on . The resul t s of th e
f i el d ex pe r i men t ar e s i mil ar t o th e gr e e nhou s e stud y bu t the r e a r e d i ff e r e n c e s
be t ....e e n t he pep pe r a nd melon c r op s , du e to di f f ere nc e s i n cr op ca no py. The
d e gr a da bl e p la s tic mulc h e s ; BL+NT27, XQ·l573 , XQ- l 571 and BL· NVl 5 s up p r es se d
early sea so n nu tsedg e gec ve h c ompar ed t o t he ba r.eg r c u nd and c l e a r pl a s t i c mul ch
i n bo th t he pepp e r s a nd mel on s . Howe ve r, by th e e nd of th e s ea so n, i n th e
pep per s , BL -NT2 7 was the on l y d e grad ab le plast i c mul ch th a t si gnifi c antl y
r educe d nut s ed ge t u ber i z a t i on co mpa re d t o th e bare g r ou nd and cl e ar pl a s ti c mul ch
plo t s. BL· NT27 was s t ill i n ta c t co mpared to t h e o t her d egr a d a bl e s that had
comp let ely degrade d , e a rli e r in th e sea son, a ll owin g su b s e qu ent nutsedge
emergence a nd g r owt h. IRT - 76 p l a s t ic mulc h a lso r ed uced n u ts edg e t uberi za ti on
in th e p epper s. The me l on c an o py wa s much d en s e r t h a n th e pe pper can op y and i t
co ve r ed a gr ea te r port io n of th e pla s t ic mul ched row . BL-NVlS, which was
c ompl et el y d eg rad e d in t h e pe pp er s by th e end o f th e s e a s on , ....a s stil l 80· 90%
int a c t in t he me l ons . Th e r e f or e , BL- NV15 a l ong wi t h BL·NT 27 a nd IRT +76
sign if icant ly suppre s s ed n utse dg e t uber i zati on . Th e r e s ul ts of t h e s e s t udie s
in d ic a t e tha t pl a st ic mul ch e s t ha t t ran s mit s mall a mounts of l i gh t ca n
pot en t ia ll y sup pre s s ye ll ow nu ts ed g e .
l Cl ou c e s t e r Coun t y Ag r ic u ltu r a l Ag ent, Ru tger s Coop erati v e Ex t ension , Cl a y t on ,
NJ 0831 2 and Ass oci at e Prof e s s or , De pt. o f So ils and Crop s, Rut gers Univer s ity .
Brid ge t on , NJ 083 0 2

92
son. FUMIGANTS AND HERBI CIDES FOR WEED CONTR OL
UNDER CLEAR PLASTIC MULCH IN VEGETABLE CROP S
B. A. Majek and P. E. Neary'
ABSTRACT
The influen ce of clear plasti c mulch on th e emerge nce of ten summer
annu al weeds was eva luated in 1989 and 1990. The po p ulati on of nin e
weed s was aff ected by the mulch in at least one of th e two years. Lar ge
cra b gras s. giant fo xtail, common p urs lane . bam yardgrass , and fall pa ni cu m
pop ulati ons were high er un de r the mulc h . Common ragw eed, ve lvetleaf,
and common lambsquart er popu latio ns were lower under th e mulch tha n in
tille d so il. Pen n sy lvania smart weed pop u lation s were unaffe cted by the
mulch . Smooth pigwe ed popul ation s were dec rease d th e fi r s t yea r an d
in cre ased th e s eco nd year of th e expe rime nt . Melons an d eggpla n t s
res po n ded to transp lanti ng thro ugh cl ea r pl asti c mu lch wi th high e r ea r ly
yi elds an d high er tot al yield s wh en weed s we re contro lled unde r t he mulch.
Oxyflu orf en or clomazone band ed un der th e mu lch before tra ns p lan ti ng at
0. 44 kg/ ha or 0 . 55 kg/ha , res pec tive ly , effective ly cont ro lle d all th e annual
weeds un der the clear p lasti c mulch . Neither he r bici de ca use d inju ry t o
either crop . Metha rn inje cted into th e t ri ckl e ir ri gati on syste m or 1, 3­
di chloropr opene p lu s chloro pic rin shank ed into the so il immediat ely bef ore
th e p lastic was laid also effecti vely contro lled the weeds , b ut t he
fu migant s were less cons iste n t. Metha m did not reac h the edges of the
pl asti c, whi ch re sulte d in some wee d gro wt h that was roo ted where th e
tr ick le ir ri ga tion did not wet. Appli cation p robl ems redu ced the
eff ectiv enes s of the l, 3-di chl orop rop ene p lu s chloro p icri n tre a tmen t in
1990 .
\ Assoc. Prof., Ru tgers Univ ., Bri dgeton, NJ 08302 -9499 an d Agr.
Agent , Glou ce ste r County, Clayton , NJ 08312-1 095

93
RESPONSE OF CUCUMBERS , SNAP BBANS , AND WEEDS TO RYE ALLELOCHE.MICALS AND
SPRI NG- PLANTED COVER CROPS
W.R. Chas e, A. R. Putnam , and 8. H. zandst ra 1
Thre e a lle lochemi ca ls bel ieved to be re l ealled from t he br eakdown of
rye , 2, 4 - dihyd roxy - l , 4 (2K) - beneoxaeLn - a -cne (01 8011.) , 2 (3H ) ­
ben zo xa zo l i no ne (BOA) , and 2. 2 ' - o xo -1, l ' -az o ben zen e IAZOS) we r e assay e d
for t oxicit y on c uc umbe r (~ eat ivus L .), sn ap bean (~
~ L .), bar nyar dq r a s s (~~ (L.) aeeu v , ) a nd
ga rden c r e s s (~ ~ L.) . In gen e r al, plant -der i ved DIB Oll. a nd
BOA wer e mo re toxic t o th e crops t han AZOB. I n cont r a st , th e
microb i a lly -pr od uced AZOB was mor e to xic t o bar nya rdg r a ss t h a n to t he
crops . Combinations o f al l e l oc he mi c a ls c aus e d eithe r antagonist ic or
synergis ti c responses depend ing on the indicato r epe e Le e an d rate of
application . The be8t s ce na r i o for good. weed. control with minimal cr op
i n jur y would be the rapid co nvers i on of DlBOA/BOA t o AZOB.
Spring -planted co ver crops were evaluated tor th ei r ability to
reduce weed populations i n cu cumber and snap bean dur ing the 1988 - 199 0
seasons. Oat (~sativa L .l , spr ing b ar l e y (~~ L .) and
ry e (Secal e ~ L. ) were killed wi t h g l yphosate and compared to ba re
9round an d a poplar exc e lsior (~~ Michx . J mulch. In
a l l y e ars , po p lar e xcel s i o r r edu ced we e d biomas s b y 23 - 30 \ a t 42 d a y s
a fte r seeding th e ve getab le s, c ompared to bare ground . Spr i ng -pl ant ed
cover c r op s r e d uc e d weed bio ma ss by up to 78 \. Cove r c r op s de layed
emergence an d matu r i t y o f t he vegetab le cr op s , bu t tot a l y i e l d 8 wer e not
reduced .
lR &sea rch As s oc . a nd Profs., Dep. of Horticult ure , Michigan Stat e
Uni versity, East Lansing , MI 48 824

94
RESPONSE OF THREE GRASS SPECIESTO FALL APPLIED BRUSH CONTROL TREATME1"ITS
Gregory T . Lyman. Larry J. Kuhns . and Arthur E. Cov er ll
ABSTRACT
InjUl')'to underslory grUICS from fall applied brush wnllol lJutmmU has bun • major concern 10 Pennsylvania
roadside managers , An experiment was conducted to compare the effects of several brush control treatments on tall fescue
~~S c hr eb.), red fescue

95
TABLE 1: InjW')' ratingsand percentcover for hardfescue.redfescue.and tall fescue treated on Sept. 7, 1989.
Injuryratings on May 31, 1990 wereon a scale from1-10 with a "1"indicatinggreen, vigcrousturf, a "10"
indicatin 5 bein unaccenr"blef orroadsidelurf. Percent cover was visuaJ]v rated on Oct. 7 1990.
Han:IFescue I. RedFescue I Tal l Fescue
5{3 1f}() lonl9O 513190 tonl9O 5/31/90 10{/ fJ(j
Treatment \J1la Annlication Rate Iniurv Cover Iniurv Cover Iniurv CO\ 'CT
..... (1-10) ( "' ) (1-10) ("') (1-10) ( "' I
Fosamine ammonium(FA) [2aO} 8.96 7.7 4 1 3.3 97 3.3 100
FA (560} 8.96 6.0 77 3.0 100 4.0 100
FA [840j 8.96 '.7 93 6.0 100 4.0 100
FA + CideKickl/ (280) 8.96 ' .3 '7 2_3 80 2.3 100
FA ...CideKick (560) 8.96 7.3 60 3.7 100 2.3 97
FA+ CideKick (&40J 8.96 6.7 73 4.7 97 2.7 100
Imazapyr [560]21 0.Q35 4 .7 100 4.7 97 2.7 100
lmazapyr 0.07 6.3 90 3.0 100 4.7 100
1m""""
0.105 9.0 SO ,.3 93 6.0 100
MetsulfW'On methyl (MSM) 0.021 2.3 97 2.3 100 2.0 100
MSM 0.042 2.0 100 2.0 100 4.0 93
Triclopyrcster(I'E) 4 .48 2.3 97 1.3 100 2.3 97
FA + lmazapyr 6.72 + 0.035 6.7 80 3.7 97 3.7 100
FA + Imazapyr 6.72 + 0.07 7.0 33 ' .7 77 7.0 77
FA+ MSM 6.72 ... 0.042 3.3 93 4.7 100 2.0 100
FA+TE 6.72 + 0.56 '.0 77 4.3 100 1.3 97
FA + Imazapyr+ MSM 6.72 + 0.035+ 0.042 8.3 67 '. 0 100 8.3 77
FA + TE+ MSM 6.72 + 0.56 + 0.021 3.0 93 2.0 100 1.3 100
CidclGck O.50%v/v 2.7 73 2.7 87 2 .0 100
Clean CUI+ Pine 31 0.50%v/v 4.0 100 3.3 97 4.0 100
L.5.D.rP=O.05 2 .6 32 25 19 2.4 rs
1/Cidckick sprayadjuvant,addedat 0.25%vtv,JLB International, vcroBeach,a .
21Thecarriervolumefortheremainingtreatments was560 1Iha.
3/ CleanCut plus Pine spray oil adjuvant, Arborchem Products Inc., Fon Washington, PA.

96
LOW-VOLUME BACKPACK APPLICATION OF GLYPH OSATE FOR BRUSH CONTROL
J . L. Wilhm, J. S . Gabric and H. W. Caldwell
ABSTRACT
Aqueous spray solutions containing 5% a nd 10% Vjv
co nce ntr ations of glyphosate2 he rbicide wi t h 1 . 5% vIv of a
non-ion i c surfac tan tJ were applied through a backpack spra yer to
sma ll «1 5 ft . ) br ush. The noz z l e used was e ither an ad jus table
s t ra i g ht-s t ream noz z l e or a s p r ayi ng Sys t e ms TXVS-6 Cone j e t R
no zzle modi f i e d to s pra y a s t r a i ght strea m. Appli c ations wer e
ma de by spr a y in g th e fo lia ge in a l at e r al zig- za g motion from th e
to p to th e bo ttom of the p la nt be in g spray e d. App ro xim a t ely 50%
of th e f o l i a ge i s c ontac ted, bu t no t soa ked as th is is a
low -v o l ume app lic a t ion. In smal l , open b ranched trees,
appl i ca tions need only be made t o one side. In thick foliage or
mul t iple stem roo t sprouts, applications mus t be made from seve ral
sides to ensure ad equate spray cove rage . Spray volume per acre
will va ry with density, but have typically ranged f rom 10 t o 25
gallo ns per acre.
For most species sprayed, there was no difference in
cont rol be tween t h e 5 % and 10% v/v co nce nt ra tion rates . However,
s ympt oms appeared more qu LckLy o n man y sp ec i es wit h t he hi gh e r
rate . Spec ies co nt ro lled by the 5% v/v ra t e incl ude sa s safrass
(Sas sa f rass alb id um) , b lack lo c u s t (Rob i n ia ps eu d oa ca c ia), ch e rr y
(Pru nus s er oti na ) , r ed mapl e (Ac e r r ubra) , re d a nd whi te oak
(Que r c u s r ub r a a nd Q. a lba) , ye l low pop la r ( Li r iode nd ro n
tUl i p i fe ra) , s umac (Rhus spp .), r e dbu d (Ce rcis can adensi s),
syc amore (P latan us occidental is), a nd swee tgum (Liquidambar
s ty ra c i f lua). Te n pe rcent v/v concentra tions were needed to
con trol shagbark h i c k or y (Carya ovata) a nd Eas t e rn red ce dar
(Jun iper us virginiana) . Variab le results were seen wi th both
rates on mulberry (Morus epp . ) and American elm (Ulmus americana ).
One po ss i ble explanation for poor American elm cont rol may be that
t he small leaves o f this specie s may have p revented sufficient
spray coverage of t he low -volum e spray .
Th i s type of applicat ion may be pre f erable to h igh -volume
ha ndgun applica ti o ns in lo w-br u s h d en s it y s i t ua tions , in rough
t e rrain, i n resi d e ntial areas , or in e nv i ro nmental ly s ensit i v e
areas . sin c e th e ap p l i c at i on is sp e c i fic to b ru sh, des i rab le
und ers t ory i s mai nta ine d and ob je c t iona b le brown o ut can be
avo i d e d . Th i s t e c hn i qu e also o f f ers a n al t er n a tive t o s ummer
basal ap p licatio ns s ince t he s tr a i ght s trea m nozzle enab l es qu i c k
applic a tions standing away from th e s tem r at her tha n nex t t o it.
1 Prod uc t Development Associate I, Sales Represe ntative I I I, and
Senior Sales Specialist . Monsanto company. 11550 North Meridian
St r e e t , suite 200 . Cannel , IN 46032
2 Acco rdR, Mon s a nt o
3 X-77 R spreader , Valent corpora t io n

97
A COMPARI SON OF SEVERAL DlLUENTS USED BAS AL BARK HE RBICIDE
APPLiCATIONS TO CONTROL ASH AND BIRCH
Gregory T. Lyman, Larry J. Kuhns. and Arthur E. Govert /
ABSTRACT
In recent years, seve ral dilue nts have beco me available for use in basal bark applica tions as an
alternative to diesel fuel or kerosene. In this study diesel fuel, two comme rcially used prod ucts
(Basal o u v and Rile Way31), a vegetab le oil (Soy-Dex'"), and a para ffin ba sed petrol eum oil
(Penetrato rv ) were evaluated for their co ntrol of green ash (frnx inus oe nsy lvanjca Mar sh.), and
black birch a.k!Y.lil krilll L.) when used a carrie r for triclopyr. Naturally growi ng stands of ash
andbirc h with stem cali pers ranging from 2.54 em to 1O.I6cm were selected for treatmen t, A
solution of 20% Garlon 461and 80% diluent was used for each of the five dilue nts. Eac h dilue nt
was appli ed at two rates; 1.0 and 2.0 ml solution per 2.54 em stem circ umference. Twe nty stems
were utilized for eac h treatme nt and they were arranged in a randomized comp lete block des ign. In
early April 1989, the diame ter of each stem was measured and recorded, circumf erence was
determin ed , and the approp riate dose was ca lculated. The solution was applied evenly arou nd the
stem at a height of 30-40 cm using a hypodermi c needle and syringe to co ntrol accuracy. In
September 1989 and 1990, each stem was rated for control on a scale of 0-5 with a "0" being no
treatment effec t and a "5" indic ating no visible living tissue.
The da ta for stem size wasanalyzedand there was no significant difference in size between the
treatment s for eac h spec ies. The means for injury rating at eac h ratin g da te are repo rted in Tab le 1.
In 1989, ash control with Soy-Dex was significantly lower than all other treat men ts. Vinual ly
complete co ntrol was achieved with dies el fuel, Basa l Oil , Rite Way, or Penetraror. There was no
differen ce in contro l for these prod ucts at either rate . By 1990, contro l prov ided by the low rate of
Soy-Dex had decrea sed and was significantlly different than all other trea tments. Injury ratings for
the high rate of Soy-Dex increased slightly and were not statistical ly differe nt than the other
diluents . Contro l provided by diese l fuel, Basal Oil , Rite Wa y, and Penetrator did not change from
1989 (0 1990 .
Control of birch was variab le between treatments and rates in 1989. The low rate of all
diluents provided poorer control rati ngs when compared to the high rate , yet the only difference
that showed significance was between the rates of Soy-Dex. The low rate of Rite Way was
significantly better than the low rate of Basal Oil, Soy-Dex, and Penetrator, but not diesel fuel.
The low rates of diese l fuel and Rite Way were not significantly differe nt than the high rates of any
diluent, Th e only signific ant differe nce between the high rates was between diesel fuel andSoy ­
Dex . By 1990 the low rate of Soy-Dex was not differe nt than the low rate of Basal Oil or
Penetraror , bu t was significantly lower tha n all other treatments. All othe r diluents and rates were
not different from each other.
Initially, birc h control levels were lower than ash in 1989, but mo st treatme nts were similar by
1990. In both speci es, the I ml solution/2.5 em circumfere nce rate was the mos t cost effi cient.
Scy -Dex was the onl y diluent that was inferior to diese l fuel. All other diluems provided the same
level of control when compared to die sel fuel. None of the diluents were supe rior to diese l fuel.
By having no difference in efficacy . vegeta tion ma nagers can consider other attributes of these
diluents when makin g a control strategy for these two spec ies.
1/ Proj ec t Assistant, Professor of Omame mal Horticulture , and Sr. Researc h Technologi st,
res pecti vely, The Pennsy lvania State University, Univers ity Park, PA 16802
2/ Basal Oil , Arborc hem Produ cts, Inc ., Fo rt Wa shington, PA
31 Rite W ay, N.G. Gilbert Corpo ratio n. Muncie, IN
4/ Soy-De x vege table oil adj uvant, Helena Chemical Co., Memphis. TN
51 Penerra tor non-io nic spray adj uvant, Helena Chemical Co., Memphi s, TN
61 Gar lon 4 herbic ide, an emul sifiable co ncentrate conta ining 480 gil triclopyr.

98
TABLE 1: Mean injury rating s to green ash and black birch treated in April 1989 with a 20%
solution of Garlon 4 11in five diluents, and evaluated September 1989and August and September
1990. Injury was rated on a 0 to 5 scale. with "0" being no treatmen t effect, and a "5" indicating
death of the stem. Each value is the me an of 20 ob servation s.
InjUry Ratin gs
ml solution! 2.5 em Green Ash Black Birch
Diluent stem circumference 9/89 8190 9/89 9190
(-- - ------------------- 0-5 ---- ---)
Diesel Fuel 1.0 5.0 5.0 3.8 4.9
Diesel Fuel 2.0 5.0 5.0 4.6 5.0
BasalOil U 1.0 5.0 5.0 2.6 4.4
Basal Oil 2.0 5.0 5.0 3.5 4.8
RiteW ay3f 1.0 4.8 4.8 4.3 5.0
Rite Way 2.0 5.0 5.0 4.5 4.9
Soy-Dex" 1.0 4.0 3.6 1.9 3.6
Soy-Dex 2.0 4.0 4.3 3.3 4.3
Penerratorv 1.0 4.8 4.8 3.0 4.6
Penetra tor 2.0 4.8 4.9 3.8 4.9
L.S.D. (p=0.05) 0.9 1.2
1/Garlon 4 is an emul sifiable concentrat e containin g the acid equivalent of 480 gil tric1opyr,
Do wElan co , Ind ian apoli s, IN.
1) Basal Oil, Arbo rchem Prod ucts, Inc ., Fort W ashington , PA.
3/ Rite Way , N.G . Gil bert Corporation , Muncie, IN.
4/ Soy-Dex vegetab le oil adjuvan t, Helena Chemical Co., Memp his, TN.
5/ Penerra tor non-ioni c spray adjuvant, Helena Chem ical Co., Memphi s, TN.

99
USB OF COVER CROPS IN LOW-INPUT nE D MANAGEMENT SYST EMS
FOR CORN PRODUCTION
J oh n R. Teasda le 1
ABSTRACT
The objec t ive of th i s r e se ar ch is t he deve lopment of weed
management sys tems for no- t illag e c orn produc tion t hat r e du ce
herbicide and n i trogen inputs . Res e a r c h emphasis has been p l a c ed
on a nnu al l e gu me cover crops be c a u s e of the de monstra ted nitrogen
co ntri buti on to co rn. Th i s report summarizes progres s fro m f ield
exp e ri ment s cond uc ted dur i ng 1988 through 1990.
Residue of h ai ry vet ch (Viola vil losa Rot h ) a nd crim s on
c l ove r (Tr i f olium in ca r natum L.) s uppr e s s e d weed es ta bl is hment
with in the f ir s t mont h af t er c orn pl ant ing in t reatmen ts without
res i dual her bici de . For exam p l e , hairy vet c h residue s uppressed
weed dens i ty ov e r 3 yea rs by a n aver age of 56% co mpared to th e
co ntr ol t r e a t ment . Su f f icient wee ds bec ame established that weed
bi omas s at ta s s e l li ng was sim il a r t o that in co ntrol pl ot s in tw o
out of thr e e yea rs . On the other hand, if hairy vet c h remained
ali ve until nat ural se ne sce nc e in June, weed densit y was
suppressed by 88% a nd weed biomass a t t a s s e lling was r e du c e d by
61%. Pla nting corn in 38 c m rath er tha n 76 cm r ows and dou ble
rath e r tha n c onven tio na l dens i t y i mproved weed contro l f or
sel e cte d c ove r cr op t rea tme nts. However , no co ver crop tre a tment
wit hout herb ici de has provide d weed co nt r ol a s effective or a s
c onsi s tent as tha t prov ided by h erbicides .
Cov er crops , in some ins t a nces , have interfer ed with corn
pro du ctio n. Hai r y ve t ch a nd crim son clo ver re sidue de cre ased
corn stand by 32% an d 12%, r especti vely, dur in g a seaso n wit h
cool, wet con dition s f or c or n germinat ion. Li ve, unmanage d ha i r y
vet ch sev e r el y in hib i ted ear ly corn deve lopment a nd resul ted in
an 87% y ie ld reduct ion du r i ng a se a so n i n wh i c h v e t c h growth
ext e nded unt il late Jun e . Alth oug h li ve hairy ve tc h provided
i mpr oved weed control compa re d t o ki l l ed hairy vet ch , so me
manageme nt with pos teme rgence herb i cides may be necessary t o
pre vent e xc e ss i v e inter ference wi t h c or n.
Cor n y iel ds f r om tr e at ments with cover crops and/or narrow
r ow s pac i ng but with out herbic ides were not s i gn if ica nt l y
differen t th a n y ield of th e standa r d herbicide t r e a t ment in a
year wi t h l ow weed compe t i t io n but were s ignificantly lower in a
ye a r wit h h i gh weed compe ti tion . However , treat ments wh i c h
comb i ned herb icides at re duced r at e s wi t h cov e r crops an d/or
nar r ow r ow spacing cons istently y iel ded a s we l l as the standard
herb i c i de t r e a t me nt . The s e results suggest that cov e r crops will
ne ed t o be in teg r ated wi t h some herbicide tec hno logy t o ac hieve
con si stent no-till a ge c or n produ ction.
' Pla nt Physio l., USDA-ARS , Bel t sville, MD 20 705 .

100
Weed Control and Cover Crop Managemen t
for Ridge-Till Com
Frank Webb and Mark Causey'
ABSTRACT
Field experiments were conducted in 1989 and 1990 at George town, Delaware with
different herbicides and rates across three cover crop variab les, rye (~~ L.),
crimson clover (Trifolium incarnatum L.) and volunteer cover in ridge-t ill corn (Zea
!I!ll,}§ L.). The statistical design was a split-plot arrangement of a randomized complete
block design. All plots received two ridge cultivations with a standard ridge-till
cultivator. In both years the rye cover interfered with the cultivation process because of
the large amount of cover crop residue. Visual nitrogen deficiency was evident in tbe
rye cover plots with a total of 102 lbs of chentical nitrogen applied to all plots. All
herbicide tre atments yielded significantly higher (Table 1) than the no herbicide plots
for both years. The rye cover plots yielded significantly less than the other covers where
no burndownherbicide was used even in combinationwith one x rate of atrazine,
metolachlor and 2,4-D applied preemergence for both years due to growth competition
with the crop. There were no significant differences between weed control ratings or
corn yield with one-half x rates of soil residualherbicides as compared to one x rates.
In 1990 crimson clover plots, in combination with any herbicide treatment, produced
higher yields than the other covers as a result of a noticeable nitrogen deficiency
occurringin the study.
'Extension Specialist, Weed Science, University of Delaware
Extension Associate, Weed Science, University of Delaware

Table 1. Herbicide and CoverCrop Response in Ridge-Till Cora 101
1989 1
-'LI2 -'LI2 WJ. ..2LlL ..2LlL .ill.- .2LlL W1 U.!.!.
Lg,
"-
Rate Cover M~~ Crab- Commoo YlCld "~b- Commoo Ceab- Yickl
Ir=ou.ll lllIA Kill..... lIil ~ IJlllim !>ill I!!J:l=l sass h!!.bm
RyeCover
"'"
99. 90. no
Bicep 2.25 80.0 ,5< 62.5 TI3 UU 1OJ.
2,4.D E 25
C.Clo.... er
Bicep ' 2S no 35.0 92.5 923 140.1 98. 96.5 875 " d
2,4-0 E 25
NO CO'o'eT
Bicep 2.25 55.0 ,0.0 86.0 89. 126.0 955 8S. 875 116.9
2,4·D E .2S
1"0 cover
Bicep 1.13 '25 ,0.0
2,4-D E .2S
84. 75.0 1333 88.5 82.5 825 ' ''' 5
C CIo''CT
Bicep 1.13 60.0 .en 78.8 -na 1.30' 9 1. 875 8S. ll 8.3
2,4-0 E 25
Rye Cover
Bicep 1.13 82.5 30.0 SO.O 513 lOS. 923 8S. no 103.7
2,4-D E 25
Rye Cover
HonchO .7S 84.8 845 863 89.8 131.5 99.0 88.8 83.8 101.3
Bicep 1.13
s-n 1.00
c.ce -«
Honcho .7S 89.8 99.0 93.8 90.0 133.0 94.8 88. 863 119.3
Bicep 1.13
x-n 1.00
No Co\-er
Honcho .7S 885 .895 93.8 90.0 141.0 923 88. 863 1103
Bicep 1.13
x-rt 1.00
No CO\'er
Gramoxone 38
x-n .2S
99. 99. 96.0 913 134.7 923 8S. 863 100.2
Bicep 1.13
C. CIovcr
Gramoxone .38 99. 99. 925 92.5 132.2 96. 825 80. 118.7
x·n 25
Bicep 1.13
Ryeccver
Gramoxonc 38 99.0 99. 63.8 70.0 116.4 98' 895 82.5 97.1
x.n .2S
Bicep 1.13
NoCo vcr 0 0 0 0 0 73.7 0 0 525
No Herb.
C.CIo-.'er 0
"'.
0 0 0 .>1 225 0 625 23 .1
No Herb.
Rye Cover 0 225 0 0 0 39.4 55. 0 463 285
No Her b.
LSD(.OS) 22.1 215 10 . 135 ain 213 12Jl 121 .8.0
""

102
Biological and Economic Analysis of Ridge Tillage in Corn and Soybeans
B.H. Marose', M. Heller , T.e . Harris. and Y.M. Kibler
ABSTRACT
The technique of planting and cultiv ating crops on ridges was first developed more than thirty
years ago as a soil and water conservation practice in me Mid-west. Today. there is renewed interest in
ridge tillageas a meansof reducing the economic andenvironmentalcosts associated with heavy reliance
upon herbicides.
In 1988 a six year proj ect was initiated to evaluate ridge tillage in comparison to no-tillage and
conventional tillage systems for a typical corn-soybean rotation under mid-Atlantic coastal plain
conditions . The experiment focuses on the economics of production and on the long term changes in
weed species and density resulting from substituting varying degrees of tillage for some herbi cide inputs.
A ninet een treatm ent experiment was established at the Chesapeake Bay Foundation's Claggett
Farm in Upper Marlboro, Maryland on a silt loam so il. The 20' by 70' plots were arranged in a
randomized complete block design with three replications. Plots were estab lished using full size farm
equip ment including a Buffalo ridge tillage plamer-culn vator and no-tillag e cultivato r.
The six ridge tillage, four no-tillage, and six conventional tillage treatments were selected to allow
comparisons within and between tillage systems, between primary and secondary tillage operations, and
between banded and broadcast herbicide placement. In addition to the fixed treatments, one variable
treatment for each tillage system allows annual modifications in selection and timing of herb icides and
secondary tillage pra ctices . The variable treatments reflect a best management approach to minimizing
inputs and maximizing returns as weed problems change over time.
Weed counts, weed and crop biomass, and crop yield data are collected and analyzed by analysis
of variance using a RCB model. An F-LSD (p= .05) is used for general treatment comparisons with
contras ts calculated for specific planned comparisons . Corr elations are run between weed count, biomass,
and yield data . Econo mic analysis is conducted to compare differences among the nineteen rrearments.
The budget model used to assess profitability takes into account variab le costs, equipment costs , farm
size , and equipment age.
In 1988 and 1989 corn yields from ridge tillage plots were compar able to no-tillage and
conventional tillage plots with standard management pr actices. Weed control in ridge tillage was good
in most ridge tillage plots. Only in the no herbicide plots did mom tngglor ies become a problem within
the row. Tr eatments involving tillage had greater numbers of hcr senettle, but lower overall biomass.
The var iable costs of prod uction, such as herbicide, fuel, and labor , tended to be lower for ridge tillage
than for conventional or no-tillage.
I (PM Coordinator, Univ. of MD, College Park, MD 20742
~ Farm Manager , Chesapeake Bay Foundatio n, Upper Marlboro, MD 20772
) Statistician and Econo mist, USEP A, Washi ngton, DC 20460

103
Table I . T illage and herb icide treatm ents used in the biological and economic analysis of ridge tillage
in com and soybeans.
PRIMA RY HERBICIDE SECONDARY TILLA GE
TILLAGE
Ridge Broadcast - Pre Ridge + Ridge
Ridge Broadcast . Pre + Post Ridge + Ridge
Ridge Banded - Pre Ridge + Rid ge
Ridge Banded - Pre + Broadcast - Post Rid ge + Ridge
Ridge Variable Variable
Ridg e None Rotary Hoe + Ridge + Ridge
Ridge None Ridge + Ridge
No-Tillage Broadcast - Pre None
No-Ti llage Broadcast - Pre No-till Culti vator
No-Till age Broadcast - Pre + Broadcast - Post None
No-Tillage Variabl e Variable
No-Tillage None None
Conventional Broadcast - Pre None
Conv entional Broadcast - Pre Cultivate + Cultivate
Conventional Broadcast - Pre + Broadcast· Post None
Conventional Variable Vari able
Conventional Banded - Pre Cultivate + Cultivate
Conventional None None
Conventional None Rotary Hoe + Cultivate +
Cultivate

104
EFFECTS
OF A LEGUME NI TROGEN SOURCE ON COMPETITION
BETWEEN CORN AND LAMBSQUARTERS
E. Oyck and M. L i ebman 1
ABSTRACT
A two-year fie ld study was u nde rt a ke n to compare the effec ts
of n i tr oge n source (legume resid ue VB. synthet ic ni trogen
fe r t i l ize r) on competition between swee t corn (~~ L . ' s u ga r
Buns I ) a nd l ambsquarters (Chenopodium a lbum L . ) . Plots of c rim son
clove r (Tr ifolium incarnatum L .) were seeded in t h e spr ing and
af ter 1 0 we e k s gro wt h we r e mown and the residu e sha l low ly
in c or p orated. Sweet corn was p lan ted in these p lots as we l l as
i nt o p l ots fer tilized with ammonium ni trate at r ates of 0, 45, 90,
135, or 180 kg N/ ha . Th e corn rows i n ha lf o f each p lot were also
seeded with l ambs qu a r t e r s . Corn and weeds were then thinned t o
equa l de nsities in all p lots . Samples of corn and weeds were taken
every t wo weeks to assess aboveground biomass and t i s s u e ni trogen
content . To de termine patter ns of ni t rogen a v a i l a b i l i t y , soil
samp les were also periodical ly taken f ro m each plot .
I n 1989 , at tw o we e ks after corn emergence, lambsquarter
b iomas s i n t h e p lot s treated with cr imson c lover averaged 70% less
than that i n 0 N plots. At ha rv e s t (1 0 week s afte r emerge nce),
lambsquarters biomass on c rimson clover plots remained 30% l owe r
th a n t ha t on 0 N or ammonium nitrate plo ts . In contrast , corn gro wn
with leg ume ni trogen under weedy conditions out yielded weedinfes
ted co rn plots t reated with 180 kg N/ha. Ana lysis of 19 90
cor n an d l a mbs qu a r t e r dryweights shows t h e same tre nds i n terms of
sup pressed we e d growth and increased corn yie ld (on weed-infes ted
pl ots ) when the legu me residue treatment i s c ompared to those
ut i li z in g ammonium n i trate .
One poss ib le explanat ion for this d ifferential effect of
n i t rogen source on corn a nd lambsquarters grow th inv o lve s t e mpo r al
avai la bi lity of soi l inorganic nitrogen . In 1989 , plots t r e a t e d
wi th c rimson clover residue contained significant ly l es s p lantav
ail a bl e ni trogen than those treated wi t h ammonium nit rate thro ugh
th e fi r s t six weeks a fter corn e me r ge nc e . The i n it i al h igh levels
o f p lan t-avai lab le N in the so il i n synthetic fe rt i l ize r plots may
f a vor species capable of rapid, early growth and nut r ie nt captu re,
s uch as l a mbs qu a r t er s . On the other hand, a source which releases
ni trogen more slo wl y thr oughout the growing season, e . g., l e gu me
resi due, may benefit suc h crop s as corn tha t exhib it slow i niti a l
gr owt h and a d e l a y e d r equirement for nitrogen .
Res u l ts f rom thi s s t udy suggest that crop rotations involving
l e gu mes may pro vide significant weed s uppress ion benef its i n co rn
c ropp ing syst ems .
1 Graduate Res ea rch Ass istant and Assis tant Professo r,
r e s p e ct i v e l y , su st ainable Agriculture Program, Deering Hal l,
Uni ve rsity of Maine , Orono , ME 04469

105
CROWNVET CH (CORONnLA VARIA I. ) UVlN G MUL CH'S CO!'ITRIBlJTION TO
SUS TAlNABLE AGRICULTURE
N. L. Hartwi g!
Generally agricul ture as practiced today is sustainab le. Th at is not to say change isn't
necessary and certainly desirable when new techno logy comes along that will mak e agric ulture
more efficient, profitable and in harmo ny with theenvironment. Any change based solely on
making agriculture more in harmo ny with the environment without improvemen t in efficiency or
profitability will nor be economic ally sustainable. Crow nveteh used as a living mulch improves
efficie ncy of farmi ng by providing a living ground cover for com, small grain s, forag es and under
the right conditions soybeans. for the control of soil erosion without the need for terraces, narrow
contour strips and large porti ons of the farm planted to sodcrops each year. Profitabili ty is
improved because the fanner has theoptio n of using crownvetcb that when once established
should never need to be planted again instead of the costly building and maintaining of terraces and
nuisance of COntourfarming with its associated short and point rows. Crownv ercb can be
managed by using the same herbicides that are in use today for the above crops withou t fear of
losing it comple tely. It spreads by underground root stocks which allows crown veteh to fill in
when overly suppressed . Since it is a legume, crownvetch fixes nitroge n so it does n't compete
with the crop for nitrogen and may under the right circumstances provide somenitrogen to the
crop . Mos t impo rtan tly, crownvetch works in hann ony with the environmen t by providin g a
living carpet to almost eliminate surface water runoff and theloss of soil, fertilizer and pesticide s to
streams and lakes.
1Prof. of Weed Sci., Dept. of Agro nomy, Th e Pennsylvania State Univer sity , Uni vers ity Park,
PA 16802

106
Potential Herbicide Reductio n in Reduced TiUage Potatoes
L.E . Lanfranconi and R.R. Bellinder'
ABSTRACf
Field experiments were conduct ed in 1989 and 1990 to determine the effect of mulch
density and herbicide prog rams on weed suppression and potato (S.2lArrnm~ L.) yield.
Potatoes were planted into rye ~ ~ L.) killed at two timings with 1.1 kg ha-l of
glyphosate to achieve 1200 and 1800 kg ha', and 1850 and 2300 kg ha" in 1989 and 1990,
respecti vely. The weed control programs included conventio nal tillage (CD plus mechanical
cultivation; reduced tillage (RT) with a full (I x) rate of I inuronand metolachlor (1.7 ka ai ha''
each) applied 10 days after planting (OAP) ; RT with a O.67x rate of metribuzin (0. 17 kg ai ha- I)
applied two weeks after hilling; and RT alone. All treatments were hilled five weeks after
planting. In 1989, mulch density had no effect on redroot pigweed~~
L.) and common lambsquarte rs (Chenooodium illm.mL.) population s. In the between- row spaces
redroot pigweed emergence at 2, 4 and 12 weeks after planting (WAP) was significantly greater
where cultivation was used than in undisturbed rye treatmen ts. In the in-row spaces at 4 and 12
WAP redroot pigweed and common lambsquarters responded differently to herbici de rates and
tillage. While reducing tillage decreased com mon lambsquarters populations , redroc t pigweed
popula tions decreased only with increasing herbicide rates. In 1990, in both in-and-between-ro w
spaces redrcot pigweed and common lambsquarters populati ons were significantl y higher in the
cr plots at all timings when compared to the undisturbed rye plots. Weed numbe rs 12 WAP
were significantly reduced as a function of mulch density in 1990. Total weed dry weight at 4,
8 and 12 WAP were significantly higher in CT than in RT . In 1989, total and marketab le yields
decreased as mulch density increased. Yields were greates t, at both densities, when the Jx rate
of herbicid es was used. Convention al tillage withou t herbicides and RT with lower herbicide
rates applied after hilling produced equivalent yields. Regardl ess of mulch density, the lowest
yields occurred in the rye mulch system without herbicides. In 1990, mulch densities did not
affec t yields. Total and marketable yields were significantly higher where rye residues were left
undisturbed prio r to hilling than when mechanical cultivation for weed control was used. In
contras t to 1989, the lowest yield in 1990 occurred in cr plus culti vatio n treatmen ts.
'Grad. Student and Assoc . Professor , Department
University, Ithaca, NY 14853.
of Fruit and Vegetabl e Science, Corn ell

107
EFFECTS OF MULCHES ON WEED CONTROL AN D PEPPER YI ELD
M.J . El se and F .X . Mangan 1
ABSTRACT
An experime nt wa s c ond u cte d to d etermine th e e f f ect o f mul ch e s
on y ield o f pep pers (~ ll.nD..!.nU!l L . ' Me l od y ' ) a nd gr owth o f
we eds . The effec t of thre e - f oo t wi de strip s of bla c k plasti c
mu l c hes was s t ud ied in sid e-b y-si de b locks in whi ch a stand o f
ha ir y v e tch (Yi.Q..i.a Y.i..l.l2:ill Roth ) a nd rye (~ ~ L .) was
e i t her mowe d a nd left on the s ur f a c e of t he sailor t illed i n.
Weed-free t re at ments were inclu d e d so t ha t t he ef fe c t s o f weeds
c ou l d be differ e ntia ted from o th er e f f e c t s of th e mul c hes whic h
co u ld infl uence y ield s . I n t he weed -f ree pl ot s , yi eld s were hi ghe r
and produ ction began ea r lier i n t he s easo n in ti ll ed plo ts a nd i n
plots with bla ck plast ic. Some o f the r ed uct i ons i n yi e ld in th e
no - ti ll t r e atm ent s may have r e su lt e d from diff i culti e s en co unt ered
i n tra nsp l ant ing i nt o un t il l e d soi l , bu t s o il tempe ra ture
d if f e r e nces also s ugg e s t th a t red uce d soi l tem per atur e s in t hes e
plo t s wa s a fac tor. Yi e l ds i n th e unt il led pl ot s i ncrea s e d late r
in t he season . Yie l ds co uld not be c ompa r e d a mong unwee de d
t re at me nt s , because ev en th e mulc hed pl ots had we e d growth whi ch
red uced pepper yields t o nearl y nothi ng . The tw o majo r wee d s pecies
pre sen t were common l a mbsqu a rt e r s (Che nopo d i um Sl.l.bY.mL. ) a nd la r ge
c rabg rass (~ sanguin e] is L .) . Pop ula t ions of t hese wee ds
were in ver s e l y correl a t e d wit h each ot he r , wit h grea ter numbers of
la rg e c rabg rass plan ts bei ng fou nd i n the no - till plo ts and gr e a ter
nu mber s of common lamb squa r ters p l a nts be ing en c ount e r e d i n t he
till ed plots . This exp e rimen t has t hus y i e lded some in te re s ting
eco log ical informa tio n and t he fol lo wi ng obse rva tio ns: t hat
d if f icul ties in no - ti ll vege table t r a ns pl ant in g a nd lo wer s oi l
t emper a t ur e s ude r cov e r c rop mulc hes ma y r e duc e yiel ds i n pep pers ,
and th at we e d c ont r o l mea su r e s in ad d i t i on t o c over cro ps alo ne
may be necessa r y.
Assi st an t Extens i on Specia list and Res e a r ch Ass i s t a nt,
respe ct i vel y, Depar tm ent o f Pl a nt a nd So i l Scien c e s , Un ive r s i ty of
Mass ac huset ts, Amher s t, MA 01003

108
SUBTERRANE AN CLOVER LI VI NG MULCH I N SOHMER SQUASH'
H . waters and R.D. Ilnicki
ABS TRA CT
A second s e a s on of data were col lected for a field study
involvi ng t he use of sub terranea n (s ub) clove r (~
s ub te r raneum L. 'Mt. Barke r' ) as a livin g mulc h for weed cont r ol
i n su mmer squ a s h (~ l2m2Q L. 'se nator' ) . Re su l ts of t he
fir st year of t he study ( 1989) indica ted t hat wh i l e s ubc lov er
con tro lled s ummer annua l weed s as we l l as the conven tiona l
he r b i c i de treatment , it migh t be too compe titive with squash in the
early part of the season . Atte mpts were made i n 1990 to a l leviate
some of the compet it i ve effects of subclover, s o that an acc eptable
squash cr op could be pr odu ced wi t h limited h erbicide inputs .
Tre at ments us e d in 19 89 and a ga i n in 1990 inc l ude d weed - f r e e
(us i ng bensulide and ch lo r ambe n pr e eme r genc e) an d unweeded checks
(both tilled and with no clover pr es en t ) and a f ull s t a nd of mowe d
clover . The remaining treatment s i n 1990 cons i sted of a full stand
of unmowed subclo ver, a nd two t r e at ments designed to reduce in -row
compet it ion from sub c l over with squ ash while ma i nt a i n i ng the weed ­
supp ressing mulch bet we e n rows : unmowe d subclover with 55 em
s tr ips ei ther killed with glypho sate or tilled, an d treated wit h
ben s uli de a nd c h l or ambe n . Squas h wa s hand - s e e ded on J une 5 i nto
rows 1. 8 m apa r t marke d wit h a no-ti ll corn pl anter . Preemergence
her bi ci de s wer e applie d the following day . Sub clove r was alive at
squash pl anting , a nd r e mained s o f or about thr e e weeks .
As in 1989 , su mmer annu al wee d control pr ovided by s Ubc l ov e r
was co mparable to the herbicide - tre at ed check. Unmowed sub clover
resulted in slig htl y l ower weed bi omass t han mowed clover . Full
s tands of bo th mowed a nd unmowed clo ver reduce d squash st a nd,
r etarded e arly s e a so n gr owt h , a nd delaye d harvest , result in g in
lower y i e l ds than t he herbi cide -t r eated che ck (th e highest - yi e lding
trea tment) , over the 25-day ha rve st perio d. Mowed c lo ver wa s
s lightly less c ompetit i ve wi t h sq ua s h in th e e a r l y week s of the
se aso n th an unmowe d c l ov e r , but there wa s no signif ica nt di f f ere nce
be tween f i na l yield s obtained in th e t wo tre atments . Squash p lants
g row n in al l of the su bclover tr eat me nt s pr od uced grea ter
qua nt i ti e s o f f r uit than t he unt r e a t e d ch eck. Among th e subc love r
t r ea tm e nts, yi eld was sig nificant ly improve d when c lover was
removed from t he ro ws, compared to full s ta nd s , whether k illed wit h
glyphos ate or till ed .
2
INJ Agric. Exp . Stn. Pub l i c a ti on No. J - 152 74-1- 90.
2Gr a duat e Asst. a nd Re s . Prof. of Weed sci., r espectively , Dept .
of crop science, Rut gers Uni v . , New Bruns wi c k, NJ 08 90 3.

109
Use o f Subterr anea n Clove r a s a Li vi ng Mul ch i n Some Ve ge ta bles I
R. D. Il nic ki, H. Wa t e r s , and A. Enac he 2
ABSTRACT
We have sh own that s ubterrane an cl over (Trifo l ium s u bt e r raneum) or
subclover can be us e d as a l i Vi ng mul ch for ~n trol i n s ev e ra l
agrono mic c ro ps an d we con du ct ed s t ud i e s t h is pa st year to determ in e
wheth er sub clover can be us ed in veg eta ble s .
Ca bba ge (Brassica ~ ca pita ta) an d t omat o (Lyco pers ico n
~ ) t ransp lan t s were s et and s na p be ans (~ vu l garis) wer e
planted in ea r ly spring on beds pr ev i ou sl y s eeded to su bcl ov e r th e s ummer
bef ore . Treatments included mowed and urunowed subclover with or wit hou t
he rbicides applied in a band ov e r marked ro ws prior to trans planti ng or
pla n tin g . Conven tionally-t illed plots wit h herb i c id es se rve d as ch e ck s .
In c a bba ge , mowed and unmowed sub clo ver produce d excellen t con trol of
l ambs qua r t e rs ( Chenop odium albtuD L. ) and pu rslane ( Por t u la ca ~ L.)
with or without h e r bic i de s . Yield was h i ghe s t in mowed sub c lo ver without
herbi cides. Yi el ds we r e l ow whe r e su bc lo ve r wa s not mowed wi th no
improvement f r om he rb i c i de s . Yields were lowest where glyp ho sa te was
used .
Mowed or unmowed s ubc Iov e r wi t h o r wi t hout herbi cide s pro duc ed
excellen t cont ro l of pu rsla ne an d f all pe n tc we (Pa n i curn d i ch o t omifl or um
Michx.) i n tomatoes which was comparaba le to th e conven tion a lly tilled ­
her bici de ch eck . Yield was h i ghe s t where su bcl over was unmowed wit hou t
h er bicide . Mowing , with or wit hou t her bi cide , r esul t ed in l ower yie l ds .
Yie lds wer e lowes t where glyp hosate was use d on both mowed and unmowe d
areas.
Sub clo ver, with and with out ban ded he rbicides, effect ed exce llent
control of pu rslane an d fall pa n ic urn i n s na pbe ans and e qua l t o t he
co nvention a lly t illed herb icide c heck. Glyp hosat e in a band over the row
h ad no detrimental effect as i t did in c a bba ge and tomat oes .
From these s t ud i e s we conclu de th at s ubc love r li vin g mul ch ca n be
used for weed cont rol i n ca bba ge, tomatoe s, and snap be ans .
lNew Jer se y Agri c . Rxp . Station Publication No . J - 15274- 2 -90 .
2Re s. Pr o f . Weed Sc ience , Gradua te St ude n t, an d Re s . Ass oc . , r e sp ect iv el y .
Cr op Sci. Dept., Rutgers University, New Jerse y.

110
s ub ter r ane an Clo ver a nd Vetc h Mulc hes f or
Zucch in i Squash a nd Swe et Cor n
C. E. Beste and J . R. Tea sdal e ll
ABSTRAC T
Subterr anean clove r (Trifolium subterraneum L . 'Mt . Barker I )
a nd h a i r y ve t c h

III
EFFECT S OF EARLY -S UMMER MANAGEMENT OF FALL -P LANTED COVER CROPS ON
WEED CONTROL IN BROCCOLI
F . X. Mangan, S . J . Herber t an d G. V. Lit chfie ld '
Field researc h was initiated in 1990 at the University of Massachusetts Research Farm in South
Deerfield to study the effects of a fall-planted cover crop combination for reduction of nitroge n
and herbicide inputs in broccoli (Brassica oteracea var . italicay. There were three cover crop
treatments planted in the fall of 1989: Winter Rye (Seca/e cerea/e) planted in combination with
Hairy vetch (Vida viI/osa) , winter rye alone, and no cover crop. In the spring of 1990 cover
crop co mbinations were either mowed at the surface with the above-ground biomass left on top
of the soil or the cover crops were mowed then incorporated into the soil. Each cover crop and
tillage treatment was combined factorially with 0 and 112 kg/ha nitrogen and the absence or
presence of herbicide. The herbicide DCPA was employed for conventional tillage and no cover
crop treatments, and sethoxydim was used for the no-till vetch-rye and rye alone treatments.
Weed pressure in this field was moderate. The mowed rye-vetch cover crop no-till treatments
with and without the use of sethoxydirn provided good weed control and yielded comparable to
tilled treatments with herbicide. The mowed rye no-till treatment also gave good weed control,
but the yields were less than the treatments with the legume. The addition of sethoxydim
provided excellent control of rye plants that had begun to regrow. Nitrogen added from the
inorganic (fertilizer) or organic (legume cover crop) source increased the size of the weeds
compared to treatments that did not receive nitrogen. Harvest maturity was delayed for the notill
treatments compared to conventionally tilled treatments. It is speculated that lower soil
temperatures influencing growth and nitrogen mineralization in the no-till treatments were
responsible for this phenomenon.
I Research Assistant, Professor and Technical Assistant, Dept. of Plant and Soil Sciences,
Bowditch Hall, University of Massachusetts, Amherst, Mass. 01003

112
FENOXAPR OP AND BENTAZON TANK HI XES IN TURF 1
RICHARD D. ILN ICKI AND ADRIAN J . ENACHE 2
ABST RACT
Fen o xa pr op I a postemer g ence h e rb i ci d e f or t h e contro l of
cr ab gra s ses (~ s PP . ), can not be u s e d sa fely on new ly ­
se eded turf species . In a p r elimi nary s t ud y we ha v e shown t h a t
f e nox a p r op ph y t ot ox ic it y can be all eviat e d b y tan k mixes wi t h
benta zon . We c o nt i nue d thi s r e searc h in 19 90, on a diff erent site,
to determine whe ther this co mbi nati on would alleviat e th e
phy to tox ic e ffect of f e noxa p rop on new ly-se eded tu r f gr a s s es o n
d iffe ren t soil and climatic condit ions .
Thre e pere nn ia l tu r fgras s e s , Ke ntucky b lu e g ras s (.fQ.g pr at e n s i s
L.), tall fescu e (F e stu c a arun d inac e a Sc h r eb . ) , an d per en nia l
ryegrass (Lalium per e o ne L.) wer e see d e d Apr il 26, 19 90. Tr e a t ment s
were a p p l ie d Ju ne 22 (PO I ) and Ju ly 10 (P02) u sing a cO 2 - p ropel led
backpac k sprayer. Fenoxa prop was applied alone (0.07, 0 . 10, 0. 13,
0 .20 kg ai ha- 1), or with su r factan t a t 0. 25\: , and in combina tion
wi th bentazon (0.56, 0.84 kg ai ha- t ) . Sta nd, vigor, and color of
t urf gr a sses as well as contr ol of crabgrass were recorded .
Fe n oxa p ro p a l one injur ed Kentucky blu egra s s and t all fe s c ue
an d onl y s l igh t ly perennia l ryeg r ass r e g a r dl e s s when a pp l i ed .
Addit ions of surfactan t did not red uc e inj ury t o any of t h e
tu r fg ra sses . Combinations of fe noxaprop plus bent azon, with or
wi t hou t su r f ac t a n t , decreased the in j u r y effected by f enoxaprop
al one. Cont rol of crabgrass by fen oxaprop a lone was ef f e ct ive i n
all three tur f s p ec ies b ut gr e ater with the high er rat e s and
g e ne r a l l y , gr e a t er wit h the ea r l y a pp lica tio n. Add i t io n s o f
su rfac tant and/or ben tazon to fenoxaprop did no t imp rove
s igni fica ntly crabgrass cont rol.
Fr om t h i s t wo - y e a r s t ud y we c onc l ud ed th at fenoxap rop ca n be
s a fe ly us e d o n n e wl y -s e ed ed turfgr a s se s whe n t a nk - mixe d wit h
bent a zon .
' New Je r se y Agric . Exp. Stn. Publication No. J -15173 -2 -90 .
2Re s . Pr of . We e d Science and Res . As soc . , res p ec tiv e ly , Crop
Scien ce Dept., Rutg e r s Un i v ersi t y , New J ersey .

113
MULTI PLE APPL I CAT I ONS OF LOW RATES OF FENOXAPROP I N RYEGRAS S 1
R.G . PROSTAK AND R. D. I LNI CKI 2
AB STRACT
Due t o a l a c k o f eff e cti ve lab eled paste mer gen ce herbicid es
fo r crabgrass ( Di gi ta ria san gu i na l is L. ) co nt r o l a poss ib l e
so l ution migh t be t o e xp a nd t he ti me s fe noxap r op can be sa f e l y
app lied. Low rates a nd va rio us sc hedu l e s of fe no xap ro p in ry e grass
wer e evalua ted in 1990 at the Ad elph ia Re s earch Ce nte r, Ad e lphia ,
New Jersey. The objectives of the s t Udy we re t o (i) to decr e ase the
phy to toxic ef fect o f f e noxa pr op when a pp l i ed ear l i e r in t he se a son
t han recomm en ded by using mUl t i p le seque nt i a l l ow rat e s a nd (i 1)
to det e rm i ne th e effect of mUl ti pl e l ow r ates on c ra bgra ss c ontro l.
Al l treatm en t s were ap plie d in 26 0 1 of wat er ha "' a t 210 kP a
t o pere nnia l ry e g r a s s (Lol i um per en ne L. 'Palm e r ') using a CO 2 ­
pro pel led ba c kpac k sprayer . The e tiudy c ons is t e d of th r e e
replications i n a comple te ly random ized b lo ck design . Trea tments
in cl uded t wo r a t e s of f e noxa pr op (0.034 an d 0.045 kg ai ha'
l
)
applied ei ther alone early in t he seaso n or sequentia lly thr oughout
the season. Treatmen ts were applied May 31 (PO,), June 26 (P0 2),
JU ly 18 (P0 3) and August 24, 1990 (PO,,). Turf color a nd in j ury were
rated and c rabgrass con t rol was e va l ua t ed fo ur t imes dur in g the
expe rimen ta l pe riod.
NO co l or d i ff e r ence s wer e obs erv ed wi t h a ny of t he t r e a t me nt s
rega rd less o f th e t i me of appl icatio n. Turf i nj ur y was obs erved
on l y wi th the f irst a ppl icat ion o f 0 .034 kg ai ha · 1 ( POl). The ot her
treatments, bot h aft e r the f irst a pp lication a nd SUbsequent
app lications, r e s u l t e d in no t ur f i nj ury . App licatio ns of 0.034 and
0.045 kg ai ha" provided crabg rass con t r o l in ear ly season but
control was poor in late season. The t r e at me nt of 0 .045 kg ai ha "'
applied at (PO,), (POl)' and (PCJ) r e su lt e d in seaso n l on g c rab g rass
co ntrol. The r e ma i ni ng t r e at ment s resu l ted in no si gni fic an t
di f ferences be tween t hem.
Thi s prel i min ary stu dy i ndic ated th a t by using mult ip l e
se qu entia l low ra tes we ca n e xp and th e t i me of f en oxapr op
app l ica tion before and af ter t hat r e c ommende d by the manufac ture r
wi tho ut caus ing turf injury a nd s ti l l obt a i n good cra bgrass
con trol .
' New J er s e y Agric . Exp. Stn . Pub l icatio n No. J - 15 173 - 3-90 .
2under grad ua t e St ude nt an d Re s . Pr o f e s sor of wee d Sc ien c e , crop
Sc i e nce Depa r tmen t, Rut ge rs Uni ve r sit y , New Br uns wi c k , NJ , 08 90 3 .

Crab gras s Control
114
In Golf Cou rse Fairwa y Tu rf.
F .S. Ross i and J. e . Neal I
Abstr act
High inten sity tu rfgra ss m an agem ent practi ced on golf cou rse
fa irway tu rf re quir es cons ist ent an d effective crabg ra ss (Dig lta ri a
spp .) contr ol. Typ ica lly. this is ach ieved wi th pr eem ergent herbi cid es ,
h owever , fai lu re of th es e h erbicides is well known due to vari able
environmental conditio ns and misapp lica tion . We eva lua ted the
efficacy of seve ra l post em ergent herb icides for cr abgrass contr ol in
fa irway tur f. A field study was condu cted wi th 3 a pplica tion s of
feno xa prop appli ed at 14 day int erval s at 0.03, 0.0 4 . 0.06 kg ai/ h a in
300 Lili a and 0.04 kg at yha in 997 Lili a . one appli cation of dtthlopyr at
0.28 or 0.5 6 kg ai/ ha and a t 0. 56 kg al t h a in com bin atio n wi th
fenoxa prop at 0. 04 kg ai /h a, an d 3 app li cati ons of MSMA app li ed at 14
day int erval s at 1.12 kg ai/ ha with and witho u t a safene r. Ini tial
applicati ons were ma de whe n cra bgras s wa s in th e 3 leaf st age.
Fenoxapro p alone at 0.06 kg ai/h a and at 0.0 4 in combin ation wi th
dt tht opyr at 0.56 kg ai/h a provided exceptional (>95%) se ason long
contr ol. Fenox apro p at 0.0 4 kg ai/h a applied in 300 or 997 L/h a
pr ovided exce llen t contr ol (>90%). Previou s resear ch has sho wn
redu ced phyt ot oxicity to puttin g green turf from high volum e
applicatio ns of fenoxapr op a t 0.04 kg ai/ ha. Dttht opyr at 0.28 or 0. 56
kg ai/ha provid ed acce ptab le con tro l (>85%) from one a pp lica tion .
Fenoxaprop at 0.03 an d MSMAa t 1.12 kg ai/h a withou t the safener
required 3 a pplica tions to provide accep ta ble con tr ol. However the
safener. applied with MSMA. significantly redu ced efficacy. Thi s stud y
indi ca tes ava ilable options for excellen t cra bgra ss con trol in fairway
tu rf in clude. fen oxaprop alon e a t 0.06 . 0.04 kg ai/ ha a t 300 and 99 7
Lyha . or at 0.04 kg ai/ha in combinatio n wit h dtth topyr at 0.5 6 kg
a t/ba.
l / Graduate Research Ass ist ant and Assoc iate Pro fessor, Corn ell
Untverst ty. Ith aca . NY

115
CRABGRASS CONTROL IN BLUEGRASS WIlli
DIlliIOPYR
S. W. Bingham, WJ . Chism, and R.L Shaver'
ABSTRA CT
The objectives of this resear ch were 1) to evaluate dith iopyr for pre- and postemergence
Jarge crabgrass [~~(L ) Scop.] and smooth crabgrass (~~
(Schreb. ex Schweig.) Schreb. ex Muhl] contro l and 2) to evaluate different formulations of
dithiopyr for crabgr ass control and effects on Kentucky bluegrass [f2il ~ (L) cv.
Plush] growth and quality. The preemergence tests were applied in ea rly April and
postemergence test were applied in June or July.
The test sites were located at VPI&SU Turfgrass Research Center on Kentucky
bluegrass which was established in the Fall of 1987. This excellent turfgrass was mowed at
3.2 em, vertical mowed, aerified and overseeded with crabgrass seed at 375 gJ looo m' to
promote crabgrass eme rgence and growth. The mowing height was raised to 3.8 em in July.
The growth stage for one postemergence test was 3·true leaf to I-tiller with a few at 3­
tiller stage. The second postemergence experi ment was treated at 1- to 3-tiller stage with
a few 5-tiller plants.
The emulsifiable concentrate formulations (EC) of dithiopyr at 0.28 kg/h a or above
gave excellent ear ly preemergence control of crabgrass . Using dithiopyr (EC) rates below
0.42 kg/he, sequential applications were required to maintain residual crabgrass control into
October. However, sequential dithiopyr (EC) treatm ents at 0.14 kg/h a provided excellent
crabgrass contro l into October. The three granular formulations (G) of dithl cpyr evaluat ed
were MON 15178 (0.05%), MON 15181 (0.10%), and MON 15152 (0.25%). The rates of
these formulatio ns of dithiopyr (G) for excellent crabgrass contr ol through October was 0. 14
kg/ ha for MON 15178, 0.21 kg/ ha for MON 15181 and 0.28 kg/ ha for MON 15152. Below
these rates, sequential applications of the gran ular formulations were necessary for
crabgrass control at the above rates. In these studies, three times as much dithiopyr in an
EC formulation was needed for excellent crabgrass contro l as compa red to a 0.05%
granu lar formulation.
In the early postemergenc e test dithiopyr (EC) was slow to give adequate control;
however, late in the seaso n, crabgrass control was good. In the mid-postmergence test,
dithiopyr (EC) was very slow to provide excellent crabgrass control. Consistent
posteme rgence crabgrass contro l required a 0.84 kg/ ha rate of dithiopyr EC. Th e quality
of the Kentucky bluegrass was excellent and there was no apparen t injury to the bluegrass.
'Prof., Research Assoc. & Lab Spec., Dept. of Plant Path., Phy., & Weed Sci., Virgin ia
Polytech. lnst. and State Univ., Blacksburg. VA. 2406 1-0331

116
NEW TOOLS FOR SELECfIVE CONTROL OF CRABGRASS IN COOL-SEASON
TURFGRASS
P. C. Bhowmik and B. M. O'Too le l
ABSTRACf
Field experimen ts were conducted on an established perennial ryegrass

117
SELE CTE D CRABGRASS CONTROL
EVALUAT I ONS FOR MARYLAND IN 1990
P . H . De rnoeden and J. M. Krouse"
ABSTRA CT
Thre e pree mergen ce a nd two postemergence pl us preemerg e nce her b i c i d e ta nkmix
s tudies conducted in 19 90 ar e Bummarize d belo w. Her bic i d es were app li ed at
the r ates and date s shown in Tab l es 1 and 2 or as noted in 50 gpa a t 3 6 psi.
Test si t e s treated with preemerg ence he r b i ci des we re i r r i g a t e d o r r a i n o c c u r red
wi t h i n 48 hr of a p p l ication. Pl o ts were 5 b y 5 ft in si ze and wer e arranged in
a r ando mized co mp le te b lo c k wit h f o ur r e p l ic a ti on s. Percen t o f p l o t a rea co ver ed
by smoo th crabgras
on a a t o 100\
s [Digitari
s cale .
a i sc ha emum (S cre b . ) Muhl. J wa s d et e rm i ne d v i s u a lly
Dat a wer e s ub je cted to ana lysi s of varia nc e an d
significantl y different means we r e separated at P '" 0.05 b y Du n c a n' s mul t ip le
range test .
Pr e emer g en c . Stu die s
In st ud y I , most he rbi cides p rovi d e d excellent (>90 \) s moot h c rabgrass
con t r o l (T a bl e 1). Howe ver , pend i met halin (3 .0 lb /A) and DCPA provided goo d
c o nt r o l (85 -9 0\) i bensuli de ( 12 I b /A) and etho fumesate provided fai r cont ro l (70 ­
80\ ); and be nsulide ( 10 l b /A) p rovided poor control «60\ ) .
St ud y II wa s cond uc ted in a mature stand . of Flyer c reeping red f escue
(~ r ubra L . ssp. rubra) . Herbicides were a pp l i ed ini tially on 2 Apr and
sequential s o n 15 May 1990. Smooth crabgrass co ver i n un t r e a t e d p lo ts a ver ag e d
61\ o n I sept and all treat ments (oxadiazon 2G at 3.0 and 4 . 0 l b / A; pend ime thalin
60DG a t 1.5 + 1.5 a nd 3 .0 lb /A; p r o d i ami ne 65 0G a t 0 .50 and 0.65 l b /A ; d i th i opy r
lEC at 0 .38 and 0 . 50 I b / A; OCPA a t 10.5 + 5 .2 lb / A; an d bene fin + tr ifl u ralin 2G
at 2 .0 + 1.0 l b/ A) pr ov i d e d >97\ c o nt ro l (data not sh own ) . Oxadia zon , DCPA, a nd
b enef in + t riflu ra l i n r e d uc ed F ly er cove r (b a r e gro u nd r a ng ing 13 -1 8\ o f pl ot
a r ea) s ign ificant ly whe n compa red t o u ntr e at e d p lo ts (b a r eg ro u nd '" 4 \) .
Stud y I II compared granula r f o rmu l at i o ns o f oxa diazo n a nd d i t h i op y r . All
treatments we re appl ied on 26 Mar 1990 , and smooth crabgrass co ver i n unt r eated
plots a ver aged 35\ on 31 Aug 1990 (data not s hown ). Treatment s p rovidi ng >91\
control were as fol lo ws : o x ad i a zo n 2G at 3.0 and 4 .0 lb /A; RP EXP 036218 2G at
3 .0 and 4 .0 Ib /A i MON 151 78 0 . 0 5G at 0 .125 l b /A; MON 15181 O. lOG at 0 .187 and
0 . 2 50 lb /A ; and MON 1515 2 0.2 5G a t 0.38 and 0 .50 lb /A . RP EXP 03621C 2G at 3.0
and 4 .0 l b /A and MON 151 78 0 . 0 5G at 0.0 92 lb /A pro vided 83 to 86'\ control.
Po s i:e lll.er g e n c e Stu d i es
In St udy IV (Tab le 2) , herbicid es were applied 21 Jun e 1990 when smoot h
crabg ras s wa s in t he 4-le af to 4-tiller stage . Exce ll ent postemergence a nd
su bsequen t p r ee mergence c ontrol (>90 \) was provided by dit hiopyr 1EC + MSMA6L
( 0 .25 + 0.5, 0 . 38 + 0.5, and 0 .38 + l. 0 lb /A ) , a nd dithiopyr lE C + fenoxap ro p 1EC
(0.25 + 0 .09 a nd 0 .25 + 0. 18 lb/A ). Di t h i op yr + f eno xa prop , e s p eci a ll y 0 . 2 5 +
0.18 lb/A rat e, disco lored Kenbl ue Kent uck y b lue g r a s s si g n i f ic ant l y, an d the
d isco lo ra tion persis ted for abou t 30 days . Good con t rol ( 8 7%) was provi d ed b y
di t hiopyr alone at 0.5 lb/A an d d it hiopyr + HSMA (0. 25 + 1.0 lb / A) . All ot her
treatments ga ve comme rcially unacc eptabl e co nt rol.
In St ud y V, herbi ci des wer e app lied 11 Ma y 1990 whe n smooth cr abg r a ss was
in the 1 to 3 l e a f stage (mo stl y 2 l eaf and g row i ng be l ow the per en n i a l ry eg rass
canopy) . Untreated plots had an a ve rage of 8 1\ cr a bg ra s s c ov e r on 31 Aug (data
not sho wn ) . Excel l ent po ste merge nc e and subsequent preemergenc e control (91 -99'\)
wa s prov ide d by DCPA 6F + MSMA6L (7.5 + 2. 0 lb / A and 7 .5 + 1. 5 + (1. 5 l b /A MSMA
applied sequentiall y o n 24 May»; prod iamine 6 SDG + qu inclorac 50W ( 0 .5 + 0 .7 5
lb /A); pr odiamine 65DG + fe no xaprop lEC (0.5 + 0.12 lb /A); an d d i t h i op y r (0 . 5
lb /A). Goo d con t r o l (8 5'\) was pro vided by d.ithiopyr at 0 .38 lb /A an d fair
control (78 '\ ) was pr o v id ed by pendimethali n 60DG + fenoxaprop lEC (1. 5 + 0 . 12
lb /A) •
' IAssoc. Pr o f . and Res. Asst., respecti vel y; Dept . of Agronomy , Univ. o f
Mary la nd, Colleg e Park, MO 207 42 .

118
Tab l e 1. Pre emerge nce smooth crabgrass co nt ro l i n Pal mer
peren n i a l r ye g r a sB ( La l i um ~ L .), s i lve r Sp r in g
MD, 19 9 0 .
Smoot h cr abgr as s
He r b i c i d e s-
Rate
( Ib a i /A )
o xa d t aec n 2G
Oxad i a zo n 2G
3. 0
4. 0
Pendime t h a li n 600 G
1.5 + 1.5
Pe ndi meth a.lin 6 0DG
3.0
Pro diamin e 65DG
0 .50
Prodiami n e 65DG
0.65
Dith iopyr lEe
0.38
Dithiopyr rec
0.50
Dithiopyr O.25G
0.25
Dithiopyr O.25G
0.38
Benefln 2 . 5G
2. 0 " 2 . 0
Benef ln + trifl u r a li n 2 .5 G 2 . 0 + 1. 0
Be nsu l i d e 4 EC
Ben s ul i d e 4EC
10. 0
12 . 0
Et ho fumesate 1. SEC
1.5 + 1.0
DCPA 61'
10 . 5 + 5. 2
Untr eated
Cov e r
Cont ro l
-- ~ ; ;*-;;- - - (') --;; --- -

119
DITH IOPY R FORMULAT ION S AND TANK- MI X COMBI NATIONS FOR
POSTEMERGENCE CONTROL OF CRABGRASS IN COOL-SEASON TURF
K. E. Ka c k l ey , D. C. Riego and J. M. Hi99ins'
AB STRACT
The post emergence acti vity o f MON 15100 ( d i t hi opy r ) formul atio ns fo r
cr a bgr a s s (Di gi t a ri a spp . ) co ntrol was e v a l ua t e d o ve r the last t h r e e ye ar s i n
s ma l l r eplicat e d plo ts . MON 1510 0 1 EC for mulations pr o v i de d e x c e ll e nt
po s t e me r ge n c e con trol of cr a bgr a s s pr i or to till e r fo r mat ion . Pe rf o r ma nc e
after the tiller stage of crabg ras s was not a s effective . However, ta nk - mix
co mbi n a t io n s of MON 151 0 0 1 EC form u lations with MSMAor fenox aprop hav e
pro vi ded excellent contro l of cr abgrass i n the o ne to th re e ti ller stag e .
Gra nula r formu lations o f MON 15 100 o n clay o r fe r til i zer ha v e a ls o p r o vi d e d
postemergence crabgrass con t rol. The v a rious dithiopyr fo rmulation s have
e x h i bi t e d safet y t o maj o r cool-season turf s pe c i e s such as Ken tucky bluegra ss
(fm! pratensis L.), perennial ryegr ass (Lo l i um oe renne L.), ta l l fesc ue
(~ arundinacea Schreb.) an d bentg rass (Agro stis p a l u s t r i s L. ).
' pr o du c t Deve lopme nt Represe ntatives a nd Prod uct Manag e r, I nd u s t r i a l ,
Green s a nd Residen tia l, Mons a nto Comp a ny, c /o 8404 49th Av enue ,
Colleg e Park, MD 20740 .

120
GROUND IVY AND HEALALL CONTROL IN TURF
J. C. Neal and A. F . s enesac'
Ground ivy (Glechoma hederacea L. ) and h e a l a l l (Pr unella
vulgaris L. ) are creeping perennia l weeds which common ly infes t
cool -season turf and are difficult t o con tro l with current ly
ava i lab le h e r b i c i d e s . Greenhouse and f ield tests were conducted
to eval uate two herbicide strateg ies for control ling t hese
species. Isox aben at 0 .6, 1. 1, and 2.2 kg/ha, and quinc lo rac
(BAS 5 14) at 0 .4, 0.6 , and 0. 8 kg/ha were eval uated a lone and in
comb inat ion with other synthetic auxin herbicides. In ge nera l ,
i s oxa be n was more effective in fie ld tests tha n in greenhouse
tests; whereas, synthetic auxins such as 2,4-0 and t ri c l opy r,
were more effective at lower rates in the greenhouse than in the
fie ld. In the greenhouse , isoxaben at 2.2 kg/ ha provided only
35% and 50% control of ground ivy and healall , respectively.
However, in the field, up to 99% ground ivy and 85% hea lal l
control was obtained. The l oc a l use-rates of 2 , 4-D + triclopy r
amine or c lopyralid + t r i c l op yr amine, provided only 10 t o 20%
he a l all contro l, but when mixed wit h 1 .1 kg/ha of isoxaben, 80%
to 85% c ont r o l was obtained. Quin c lorac eff icacy in field a nd
greenhouse tests were similar for ground iv y; but, for hea la ll ,
gree nho use results were superior . In fie ld t e st s , quinclorac
applied a lone at 0 .8 kg/ ha co ntrolled heala ll; but, the speed of
contro l was improved by tank mixi ng with 2,4-0. Ground ivy was
not con tro lled by quinclorac applied a lone, but was contro lled by
the tank mix with 2 ,4 -0 . From t hese tests, two viab le strategies
for impr oved control of ground ivy an d h e a l a l l in cool -season
tu rf are: quinclorac + 2,4-0 at 0.8 + 1 kg/ha, or i s oxa b e n +
synthetic auxin herbicides such as 2,4-0 + triclopyr or
clopyra l id + triclopyr. Further research is needed to optim ize
t he t ank mix ratios .
lAssociate Professor , Dep . Flor icu ltu re and Or namental
Hort iculture, Cornell Univ ., Itha ca, NY; and Weed Science
Extension Specialist, Cornell Univ., Long Island Hort ic ultural
Research Lab , Ri verhe ad, NY.

121
RESIDUAL PHYTOTOXICIT Y OF HEXAZINONE, l MAZAPYR, TE BUTHI URON, AND
TRICLQPYR ON SELECTED CROPS
c . Be n j amin Co f fman an d J. Ra y Fr an k t
ABSTRACT
Hexa z in one , ima zap yr, t eb uthiuron, a nd t ri cl opyr are
ge ner all y used for p r e a nd pos t eme r g e nc e c on t ro l o f perenni al
weed s on non -c rop land , r a n ge , a nd pastur e. F i e l d ex p e rim e nts
were esta blished i n 1988 a t Beltsv i l l e, Marylan d , to ev a l u ate the
r es id ual activity of th e s e h e rbi cide s o n s e lected c r op s ov e r a
two yea r per iod . Th e exp e r i menta l a rea was clea n c ul t iva t e d a nd
t rea ted wi th methy l br omid e p rior to the es t ab l i s hme n t of th e
research p l o ts. Plots were 3 by 4 m i n a ra ndom i zed b l oc k d e s i g n.
Herbicide treat ments we re r ep l icat ed th ree ti mes. Hexa z inone an d
teb ut hiuron were applied a t 2.2 , 4 . 5 , a nd 6 .7 kg na" , Imaz a p yr
wa s applied a t 2.2 , 4 . 5, and 9.0 kg ha - 1. Tri clo pyr wa s applie d
at 3 .4, 6.7, a nd 1 0 . 1 kg ha-' . Cr ops wer e s own o r pl ant e d i n
30 cm rows one day afte r tr e at me nt ( OAT), an d on e, t hr e e , s ix,
a nd 12 weeks after tre atment ( WAT ) in 1 9 8 8 . All p l ots we re
irriga ted to s u p p l ement ra i nfa l l an d p r ovi de a t le a st 2 c m wate r
per we ek . Vi s ua l e stimat es o f p l a nt re s p o n s es ( a to 1 0 0 ) we re
ma de a t s e lec ted int erva ls th roughout the growi ng sea s on. Te s t
s pec i e s i n cl Uded whea t ( Tri ticu m a e sti vum L. ), k id n e y be a n (
Pha s eo l u s vul ga ris L. ) , co rn ( Zea DlSY§. L . ) , squash ( cucurbit a
llim.Q L. ) , ok ra [ Abelmoschus es c ule nt u s ( L. ) Moench . ], banana
( Musa acu mina t a Co lla ), and pot ato ( ~ t ub e rosu m L . ).
Bana na s we r e tr an s pl an t s a nd pot atoes we re s own a s t ubers; al l
ot he r spe cies were see ded. In 1 9 8 9 t h e exper imen tal p lo t s were
replanted in June and Aug ust . Irriga ti o n and data co l lec t ion
were a s in 1988 . Banana was ex cl uded i n 1 9 89.
In 1 9 8 8 , c or n sow n one OAT t ole r ated t e b ut h iu ro n a t 2. 2 kg
na"! thr ough t h e e nd o f th e g r owi ng se ason, bu t di d no t tol e r at e
th e h i gh er do ses . Squas h a nd ok r a t o l e r a t e d i maza p yr a t a ll
rate s when sown on e OAT , and on e an d three WAT. The r e wa s no
t o l e r a nc e to h e xa zin on e by any s p e cie s . Cor n to l er a te d tri c l op y r
at 3 .4 kg h a - 1 whe n sow n thre e , si x and 1 2 WAT.
In 19 8 9 , pota t o tol er at ed ima zap y r at 2 . 2 kg n a " wh e reas
ki dn e y bea n an d squash t ol e r at ed tr iclopy r a t 3.4 kg h a "! in t he
June plan ting . I n the Aug us t p lan ting I corn and p ot at o t o l e r a t e d
i ma zap yr whereas squash and potato we re t ol er a nt of r esid ual
t r i c l op y r . There were no ot he r her b icid e to le rances observed i n
eit h er ye a r .
, Rese a r ch Agron omi st a nd Wee d Sc i enti st, r es p ec t ive ly , USDA,
ARS,Belt s vi ll e and Fr eder i ck MD.

122
OAT AND SOYBEAN YIELDS IN CROWNVETCHAND OTHER COVER CROPS
N. L. Hartwig !
ABSTRACT
Crownvetch ~ zanaL.) for this study was seeded on April 20, 1976. A number
of research studies rela ted to the use of cover crops for agronomic crop produ ction have been done
in this area since. In 1985 a study was set up to look at a number of different cover crops for a
fO UT year crop rot ation of com-com-oats-winter wheat/soybeans with three levels of nitrogen
applied to com when it appeared in the rotation. The trial was large enough so all crop s in the
rotation wererepresented each year. Flatpea, another perennial legume. was introducedinto the
trial from 1985 to 1987. Other cover crops included hairy vetch and winter rye which were seeded
yearly in those plot s to be planted to com or winter wheat but not to oats or soybeans. Oat yields
are presented for the period of 1987 to '90 and soybean yields for the period 1987 to '89. In each
case the year of extreme drought in 1988 is included. Yields in 1988 are a chance observation of
the influence of crownvetch and other cove r crops on oat or soybean yields in a very dry year,
It was expected that the presence of a crownvetch living mulch would have a detrimenta l
effect on oat and soybean growth and yield but oat yields were the same or better when planted. into
crownvetch regardles s of the amount of sidedressed nitrogen on the com prior to oats in the
rotation. This would indica te that even in an extremely dry year. crownvetch producing up to
about 500 Ib/A of dry matter did not result in increased competition for moi sture. In 1990. when
no nitrogen was applied to the oats. oat yields were significantly greater than most of the other
cover crop s. Flatpea didn 't have a detrimental effect on oat yields until the last year when it
became so vigorous it overtopped the oats by harve st in most plots and significantly suppressed
yields relative to the crownvetch.
Soybean yields were also not significantly affected by the cover crop in any of the years
1987 through '89. In 1988, soybean growth was suppresse d due to drought and as a result the
soybeans were not nearly as competitive as they would have been in a normal year, thus allowing a
lot of recovery growth of erow nvetch and flatpea, Soybeans yields appeared to be slightly reduced
as a result.
It would appear that both no-till oats and soybeans can be grown in a living mulch of
crownvetch without any loss in potential yield as long as the crown vetch is sufficiently
suppressed. Flatpea could perhaps also be used if a more potent herbicide program or tillage were
used to suppres s it.
lNTRODUcn ON
Research on the use of crownve tch (Coronilla varia L. 'Penn gift') as a living mulch for
agronomic crop production was started at Penn State in 1975 (1). Initial researc h from 1975 to
1980 determin ed how to manipulate crownvetch in no-till com ~~ L.) . Starting in 1981,
oats (Avena sativa L. ) was introduc ed into the rotation and crownvetch was allowed to recover one
year in four for hay to see if crow nvetch could be maintained without losing it. From 1985 to
1987 a study was set up to look at a number of differe nt cover crops with a four year crop rotatio n
of corn-corn-oats-winter wheat (Triticum aestivum L.)lsoybeans (Glycine !.!lllAL.) with three
levels of nitrogen applied to corn when it appeared in the rotation. The trial was large enough so
all crops in the rotation were represe nted each year. Flatpea~ sylvestris L. 'Lathco'),
another perennial legume, was introduced into the trial from 1985 to 1987. Other cover crops

123
included hairy vetch (Y&ia~ L.) and winter rye~~ L.) which we re seeded yearly
in those plots to be planted to com or win ter wheat but not to oats or soy beans. It was determined
and reponed mat com grown in crownvetch out-yielded com without crownvetch even in 1988
when Pennsylvan ia had its driest Jun e and July in 100 years (2,3). The research data presented in
this papercovers oat and soybean yields with or without the perennial crownvetch or flarpeacover
crops and following com whic h also had the winter annuals winter rye or hairyvetc h cover crop s.
MATERIALS AND MElHODS
Th e crow nvetch for thi s study was seeded on April 20, 1976 on a Murrill silt loam soil
(Typ ic H apludult) containing abo ut 16% sand . 67% silt. 14% clay and 2.5% organi c matt er. Th e
area was limed to a pH of 7.0 befo re seeding andit has been limed since to maintain a pH of about
7.0 . A number of researc h studies related to the use of cover crop s for agron omi c crop producti on
have beendone in this area since.
Cover crops were plant ed in block s 18.3 by 22.86 m. Each block was subdivided in
twelve 4.6 by 6.7 m plot s. Each year of the four year rotation was assign ed a strip of three plots .
The trial was rep licated 3 times.
Corn in the rotation was sidedre ssed with 0 , 77 , and 154 kg ha-t of nitrogen as UAN in a
band between each com row. No-till oars w hich followed com in the rotati on received a blanket
topdre ssing of36, 80. 73 and 0 kg ha-! nitroge n in 1987. '88. '89 and '90 respectiv ely. W inter
wheat followed oats in the rotation and was harve sted for silage in late Ma yo r ear ly June.
Soybean s we re then no-tilled into the whea t stubble in early June and rece ived no fertilize r.
D ue to recurring problem s with dand elio n~~ Webe r in Wiggers) and
quackgr ass~~ (L.) Beauv.), es pec ially in the no cover trea tme nts, glypbosa re!
[N-(phosp hono me thyI)glycin el and 2.4-D [(2,4-dic hlorop heno xy)acetic acid ] low vo latile ester
(LVE)@ 1.1 + 0.55 kg ha- l were applied Ma y 7. 1987 ; glyp hosate @ 1.5 kg ha -l was app lied
alone Apri l 21, 1989; and 2,4-D LVE @0 .55 kgha -! wasapplieda loneinOcto ber 16, 1989
before seeding oats no-till on 5/11/8 7; 3/29/88; 4/17/ 89 and 4/10/90. Dand elio n is norm ally not a
problem in a good living mulc h gro und cover but the abo ve treatmen ts were applied to all plots
going to oats regardless of the sensitiv ity of the grou nd cover to avoid tre atmen t variati ons tha t
co uldn' t be accounted for Statisticall y. Althou gh crow nveteh and flarpe a are both very sensitive to
glypbosa te and espec ially 2.4-0, applicat ions mad e before dandeli on bloom in the spring or after
several hard frosts in the fall will not result in the loss of these perennial living mul ches.
U sual ly add itional weed contro l and/or living mulch suppress ion is neces sary after the oats
has emerged since glyphosate and 2.4-0 have little or no soil residual activit y. No additi onal
treatment was needed. in 1987 but in 1988 a prem ix of brom oxynil (3.5-dib rom0-4­
hydrox yben zonitri le) + MCP A [(4-e hIoro-2 -me thylphenoxy)ace tic acid] @0 .55k gha - l each was
applied Jun e 3 in l 15 1/ha of liquid nitrogen to suppress dand elion. Due to the ex treme ly dry
weather followin g this trea tme nt it did little good. MCPA@0 .275kg/ha- 1 was applied 6/19189
wh en oa rs was in the boot stage. crownve rch 25 to 35 cm and Cana da thistle (O n i um arvense (L.)
Scop.) 45 to 60 em. Th is treatment was too little too late to do an effecti ve job of suppres sing the
cro wnvetch or Canada thi stle . O n May 25. 1990. MCPA @ 0.55 kg/h a~l was appli ed to oats,
cro wn veteh and Ilarpea 10 to IS cm tal l with excellen t suppress ion of the cro wnvetch. Th e flarpea
wa s tempo rarily supp ressed but by harvest time the recovery grow th had almost buried the oats in
some plots.
1 Ranger, Monsanto Agricultural Products Co., 51.Louis, MO

124
Soybeans were drilled in 25 cm rows with a no-till drill on 6/2/87. 6/6188and 6112/89at a
seeding rate of 100 kglha, In 1987, metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2­
methoxy-l -methylethyl)acetamideJ+ bentazon [3-(I -methylethyl)-(I H)-2,l ,3-benzothi. diazin­
4(3H)-one 2,2-dioxidel at 0.55 + 1.1kg/ha-1+ emulsifiable crop oil at 2.34 1/ha-1 was applied
June 11 for redr oot pigweed~~ L.) and annual grass control followed by
imazethapyr [(±)-2-[4,5-dihydro-4-methyl-4-(I-methylethyl)-5-oxo-l H-imidazol-2-yll-5-ethyl-3­
pyridinecarboxylic acid] at 0.1375 kg/ha-! on June 24 to clean up the weeds missed by the first
treatment. In 1988 and 1989, imazethapyr + metolachlor at 0.06875 + 1.65 kg/ha-! was applied
preemergence for annual weed control.
All treatments were applied with a tractor mounted small plot sprayer with 800 15 extended
range flat fan nozzles at IF:!kPa and 187 1/ha of water.
Both the oats and soybeans were harvested with a small plot combine. The harvested area
was 2.44 by 6.7 m out of the middle of each plot. Yields were analyzed using the SAS statistical
package as a split-split-split plot design.
RESULTS AND DISCUSSION
Oat yields for the period 1987 to 1990 were good in aUyears except 1988 when it was
extremely dry in July and August when the oats was filling. There were no nitrogen carryover
effects from nitrogen applied to com except in 1988 (Table 1). Due to the extreme drought, the
high nitrogen level of 154 kglha did significantly increase yield over the 77 kglha rate.
Table I: Influence of nitrogen rates applied to com the previous two years on oat yields when
averaged over cover crops. (n=21)
Nitrogen
Cover
Rate
a
o
77
154
Sigmficance Level (P)
LSD (P=0.05)
a Driest June and July in 100years.
1987 1988'
57
65
63
0.169
8.8
Only in 1990 was there a significant cover crop effect on oat yields when averaged over
nitrogen levels applied to the com previously (Table 2). In the first three years of the study, 36 to
80 kg/ha of nitrogen was applied each year which was apparently enough to mask any nitrogen
influenced yield differences among the cover crops. In 1990 no nitrogen was applied to the oats
and as a result there was a significant yield reduction, very likely due 10 lack of nitrogen, for oats
following com overseeded with hairy vetch where there was apparently no nitrogen carryover and
where no cover crop had been planted (Table 2). Oat yields were also significantly reduced where
Ilatpea was present as a living mulch because flatpea was not sufficiently suppressed by the
herbicide program in 1990. Flatpea was growing out the top of the oats at harvest time in many
plots. Crownvetch was suppressed very nicely in all years (data not included) by the herbicide
programs and oats yielded the most when planted into a crownvetch living mulch due to the
contribution of some nitrogen and perhaps other factors as yet unidentified.

125
Table 2: Influence of the cover em on oat ields when avera eelover nitro en rates. (0=9
rtrogen
Cover Crop
Rale
kii/ha
None
Winter Ryeb
Crownveteh
Hairy Vetch b
Flatpea
Crownvetc h + Hairy Yetchb
~;R~:: r.e~~n~)
1987

126
I CIA5676:
WEEDCONTROL FOR FI ELD CORNI N THE NORTHEAST
s . W. Cosky, S. Dennis and M. P. Whale n 1
ABSTRACT
the ef~~~~~ v~x:e~~im~;t:C;:~:7~?n1~ c~~~t~~1119i8n8g' ::::5
a~~ ~~~~dt oc~;:l(~~:
!!@Y§ L. ) 1n the North east. I CI A,5676 was app l ied a lone and in t ankm1x
combinat i ons wit h at razine 1n convent i ona l fie ld corn. Al l st udi es wer-e
conduct ed utilizin g ran domized complete bl ock design s and with thre e or
fo ur re pl i cati ons .
Applica ti on ra t e s of ICIA5676 were 50 ;1 type depend en t. Gene r all y ,
I CIA5676 was app lied at rate s fr om 0.75 l b a1/A f or course so ils wit h 3x organ i c mat ter.
Tankrnix a ppl ic atio ns were applie d wit h at ra z tne at 1. 0 t o 1. 5 lb a i/ A.
Seaso n l ong cont rol (>90X) of t mpo r ta nt gr ass weed speci es i nc l Udi ng
giant fo xtai l (Set ar i a faberi Hermm. ), l arge cra bgr ass [Oi git ar ia
sang uina lis (l. }$cop .] and fall panic um ( Pani cum di chotomiflorum Mi chx . )
have been obse rv ed fr om app l i cati ons of ICIA5676 al one . Common
lambsquarter s (Chenopodiu m UJllm!l. ) contro l i s gener a ll y obse r ved at >85%
in earl y rati ngs « 35 days after t r eatment (DAT), but may be le ss at
l ater obser vat i on dates ( >35 OAT) .
Crop t oleran ce to I CIA5676 has been excellent. Visual injur y
ratin gs « 35 OAT) estima t in g red ucti on i n veget ative growt h of co r n are
gene ra l ly < 1 0 ~ and a re comparab le to ot her acet ani lid e he r bici des . Such
symptomolog y is not apparen t at lat e r obs er vation dat es .
These st udi es indic ate th at ICIA5676 may be used succ ess f ully in
weed contr ol prog rams fo r t he cont rol of impor t ant grass and broad le aved
weed spe cie s with exce llen t c rop t ol e ra nce .
II CI Americ as Inc ., Agri cult ura l Prod ucts Group . Wilm in gton, DE
19897 .
2ICIA5676 is a formulate d combinat i on of acet ochl or and th e co rn
sa f ene r dic hl ormid (R25788) contai nin g 6. 4 l b ai / ga l and 1. 08 lb a i}gal ,
r ...c>n.a ... t i v", l v

127
rcrx 5676 IN OJRN
H. P. Wilso n and T. E. Hines 1
Corn (Zea ~ L.) herb icides fal l into s ix chemical clas ses with
chloroacetamides be ing the most comrcnty used fo r preemer qence gras s
control. Acetochlor is a chloroace tamide t hat has been eva l uated as a
corn herbicide. '!hese studies were ronducted with acet ochlo r under the
codes SC-5676 and ICIA-5676 between the years 1985 and 1990. The bo
coded products generally included dichlormid as a he rbi c ide antido te .
Initially, errphasis was placed on studies in conven tional co rn [ IPioneer
3378 1 (R)] with only a l imited mmce r of t reatme nts i ncl uded in no-ti ll
co rn . I n 1989 and 1990, separ ate adja cent st udie s conpa red acetoeh l or
with alachlor in conventiona l and no-t i ll co rn . en the Coas t al Plain
soils which served as the sites for these stud ies , annual grass con tro l
was frequently sufficient fran 1. 0 lb/A acetochlor and consisten tly high
fran 1.25 Ib/A in conventiona l corn. Control of SIOOOthpigweed (Artaranthus
hybridus L. ) , COIlIYO n l anbsqu a rt e r s (Chenopodium album L) , and COITIl'O n
ragweed (Arrbrosia ar temis i f olia L.) was hi gher fr an acetochl or than ala ­
chlor and metol ach l o r . Acetoch l or ra t es r equ ir ed f o r cont rol of ann ual
grasses in no- ti ll corn were a min inum of 1. 5 lb / A or 20% nore than in
ronventional corn. carbinations of acetochlo r with at ra zine have poten ­
tial for control of numerous broadleaf weeds and geasses in ronvent ional
and no-till rom . In the limited corrparisons of ace tochlor with aceto ­
chloe + dich lonnid , dichlonnid pro tected corn fr om ac etoc hl oe i nj ury. In
1990, some eed uct io ns in com gr owth (5 t o 12%) f rom 1 t o 2 lb / A acet o­
chlor + dichlormid were ev ident 7 weeks af t er pl ant ing conv ent io nal com
but yields were not affected; oo-till com has not responded to acet o­
chlor.
lp rofessor and Agri. Res. SCi. , Eas te m Shor e Agr i c. Exp . St n . , Va.
Polytech. Inst. and st ate Univ., pa in te r, VA 23420 .

128
PREEMERGENCE ACTIVITY OF ICIA-5676 IN CONTROLLING ANNUAL GRASSES
IN FIELD CORN
P. C. Bhowmik, B. M. O'Toole ' , and S. Dennis/
ABSTRACT
Field experiments were conducted to evaluate the preemergence activity of ICIA-5676 in
controlling annualgrasses in fieldcom. All treatmentswereappliedpreemergence on May 12 and
25, 1989 and on May 11 and 15, 1990, respectively, in minimum-till (one disking) and in
conventional-till (moldboard plow followed by disking) system. Treatments were applied with a
CO 2 -backpack sprayer at 150 kPa to deliver 187 Uha. The experimental design was a randomized
complete block with three replications. Plots were 2.3 by 3.0 m. Major weed species were large
crabgrass ~~(L .) Scop.] , yellow foxtail ~~ (Weigel) F.T.
Hubb.), common lambsquarters (Chenopodium a!l!l!!!lL.), and redroot pigweed (Amaranthus
~ L.) in both years. Com injury, percent weedcontrol, and com yields were used for
theevaluation.
In 1989 conventional-till corn, ICIA-5676 at 0.84 to 1.68 kg/ha gave excellent control of
large crabgrass, yellow foxtail, fall panicum ~ dichQtomiflorum Michx .), common
lambsquarter s and common ragweed five weeks after treatment (WAT). At 9 WAT, the same
treatments gave significantly less control (78-88%) oflar ge crabgrass than did metolachlor at I. 68
and 2.2 kg/ha and alachlor at 2.2 kg/ha (93-98% control). Irrespective of the rate, ICIA-5676
gave excellentcontrol of yellow foxtail. In 1990, all treatmentsof ICIA-5675 in combinationwith
atrazineat1.35 kg/hagaveexcellentseason-long controlofyeUowfoxtail, commonlambsquarters,
and redroot pigweed 14 WAT except large crabgrass control (less than 80%).
In 1989 minimum-till corn, ICIA-5676 (0.84 to 1.84 kg/hal controlled large crabgrass
and yellow foxtail 7 WAT as effectively as treatments of alachlor (2.2 kg/hal and rnetolachlor
(1.84 to 2.2 kg/hal . Alachlor applied preemergence at 1.56 kg/ha contro lled yellow foxtail but
gave only 86%controlofl arge crabgrass at thesame rate. Only metolachlortreatmentsat 1.84
and 2.2 kg/ha provided 79 to 84% large crabgrass control 12 WAT. All ICIA-5676 treatments
gave only 50% control of large crabgrass 12 WAT. Similar results were obtained in 1990.
In summary , ICIA-5676 applied preemergenceat 0.84 to l.l kg/ha effectively controlled
largecrabgras, yellow foxtail, fall panicum , common lambsqu arters, and redrootpigw eed in
both years under both conventional- and minimum-till systems. In general , the ICIA-5676
appearedto be less effective in annualgrass control underminimum-till system comparedto
conventional-till system.
IAssociate Professor and Research Technician, Department of Plant and Soil Sciences,
University of Massachusetts, Amherst, MA 0 1003.
')...... ~ ----=--- ,__ 101l,, .. 1l. .......... M T

129
Can ada Thistle Control in Corn
S. Glenn, L . Heime r, a nd N. Ande.r aon -'
ABSTRACT
Canada thistle (~ ~ L . ) (CIRSA) control i n corn
(Z"g,g I!@Y.§. L. ' Pi on e e r 3352') was studied in Was hingt on Cou nty,
Maryland . Th e stu dy area was planted on May 2 , 1990 . All p lots ,
except untreated contro l plo ts, were trea ted wi th 2 .2 kgj ha
atrazine and 2.2 kq jha metolachl or at plan t i ng . Paraqua t a t 0.6
kg/ha + 0 .5 (vjv) X-7 7 wa s also app lied preem ergence t o a ll p lots
that wer e to be t r eat ed wi t h post e mer gence herbicides . Pre ­
emergence appl ic at i ons ' (e -on high CIRSA) of 1.7 and 2 . 2 kg j h a
glyphosate pr oduced 78 and 8 7% CIRSA control 4 week s af ter
trea tme nt (WAT); ho wever, by 13 WAT CIRSA con t ro l was 52 an d 62%.
Tank mixtures of 0 . 6 kg /ha 2,4-D wi t h glyphosate did not improve
CI RSA c on trol compared to applications of gl yphosa te ap p l ied alone .
Preemerg en ce applications o f triclopyr + 2,4 -D ( 0 . 1 + 0.3, 0. 3 +
0.6, and 0.4 + 0.8 kg/hal and at razi ne + Oicamba (L1 + 0 .5 k gjha)
were not ef fective in controlling CIRS A. Ear ly pos teme rgen ce
applications (a u- en CIRSA) of 2 .2 kg /ha at ra z ine + 1% cr op o i l were
also not eff e ctive in c on t r o l l i n g CIRSA . La te postemerge nce ( LP )
applicati ons (au-en CIRSA) of 0.6 kg/ha 2,4 - 0 , 0.3 kg/ ha Oi camba ,
and 0. 6 + 0. 3 kq/ha 2,4 -0 + Oicamba produced 47 , 5 3 , and 80 %
control of CIRSA, respe ctively, 8 WAT. CIRSA co n tro l wi th LP
app lications of 0 .03 and 0.05 kg/ha nicosulfu ron + 1% c ro p o il was
53 and 63 %, 8 WAT. Tank mix tures of 0 .6 kgjha 2 ,4-D wi th 0.0 3 and
0. 05 kg /ha n i c o s u l f u r on produced 75 and 85% CIRSA con tro l .
Chlopyrolid appl ied LP a t 0 .2 and 0.3 kg/ha + 0 .25% X-77 produced
83 an d 92 % CI RSA control . Corn yields i n c r e a s e d 40 t o 60% when
CIRSA was effectively controlled compared to unt r eated co nt ro ls .
!L As sociate Prof . , Grad. Res. Asst. , and Aqric . Techn ., unive rsi ty
of Maryland , College Park, MD 20742.

130
Perenn i al Weed Cont rol with Nico sulfuron Combination s
N. Anderson and S . Glenn l l
ABSTRACT
Experiments were conducted in Washington Count y , Mar y l a nd to
stu dy the cont rol of hemp dogbane (~ can nabi oum L . ) (APOCA)
a n d wild blackberry (~ allegheniensis L. ) (RU BAL) i n no -ti l l age
c or n cZ§m~ L. ' Pi one e r 335 2 ') . Al l p lo ts were tr e ated wi t h 0 .6
kg jha pa raq ua t, 2.2 kg/ha meto lach lo r , 2.2 kg/ha a tr az in e , an d 0 .5 %
(v/ v ) X-77 . poet. emer'q en c e appli c at ion s we re made when corn was a t
t h e 4- to 5- le af s t ag e a nd APOCA an d RUBAL were 2 5- t o au - em high .
APOCA and RUBAL con trol wi t h ap p l i c at i on s of 0.6 k g / h a 2, 4- 0 was
63 a nd 45 % and with 0.3 kg /ha Dicamba was 55 and 60 % 6 weeks a f t er
treatment ( WAT ). Nicosulf uron ap plied at 0.03, 0.05 , and 0 .07
kg /ha plus 1% crop oil produced 85, 85, and 73 % control of APOCA
and 72, 70, an d 80 % control of RUBAL, respectively, 6 WAT . Ta nk
mixtures of 0.6 kg /ha 2,4 -0 + 0.03 a nd 0 .07 n icos u lfu ron i ncrea sed
APOCA c on tr ol (1 00%) co mpare d t o th e co nt rol ob ta i ne d wi t h e i t he r
he rbici de ap p l ied a l one . Tank mix t u res of 0.6 kg /h a 2,4 - 0 + 0.0 3
a nd 0 . 05 kg / ha n icos u lf uron also in c r e a sed RUBAL c ontr ol ( 85 an d
82 %) compared t o th at obtai ned with e it h e r h erb i ci de app l ied a lo ne .
Combin i ng 0.3 kg / ha Oicamba with n i c os u l f ur on was not a s e f f e cti v e
in con t rolling APOCA and RUBAL as the 2,4 -0 nicosulfu ron t a n k
mi xture s. Stud ies were conduc ted t o e va lu a t e joh n song rass [SQr.9.b.Ym
halepe nse (L.) Pe rs .] (SORH) con t rol wi th nico sulfu ro n appl ied
a lo ne a nd i n t ank mixt u res wit h 2 , 4-D a nd Dica mba. Combina t i ons
o f 2,4 - 0 an d Dic amba r educ ed SORRA c ont rol c ompa r e d t o th at
obt a ined with n ic o su l fu r on a pp lied a l on e 4 WAT. Howeve r , by 9 WAT,
2,4 -0 had no e f f e c t on SORRA con tro l wi th nicos ulf uron . Tank
mixtu res of 0.3 kg /ha Oicamba + 0 .0 3 and 0.05 kg /ha nicosulf uro n
contin ued t o antagonize SORRA co nt rol 9 WAT compa r ed to t hat
obtained with nicosu lfuron applied a l on e .
ill Agr i . Te chn. a nd Assoc. prof . , Unive rs ity of Mary land,
C o] ] AOA Park . MO 20742 .

131
THE EFFECTS OF ROWWIDTH, NI TROGEN
AND HERBI CI DES ON \ffiEAT YIELD
R. L. RITTERl/
ABSTRACT
Field stud ies conducte d in Maryland since 1985 examine d t he effect s of row
wi d t h , nitr ogen application , and herbici des on wheat (~ ~ L.)
yi el d .
Studies conducted from 1985 to 1987 exami ne d a variety of herbic id e
prog ram s on wheat pl anted in eit her 20 em or 10 em r ow spac i ngs . Weed con t r ol
rating s made l a t e in t he gro wi ng se ason pr i or t o wheat ha rv e st a verage d 70 X f or
the 20 em row spaci ng, wh ile t h e 10 e m row sp aci ng a v era ged 82 %. The s e v i s ua l
r at ings wer e for winter ann ual broa dl e af wee ds. prima ril y co mmon ch i ckwee d
(~ ~ L . ) Wheat y i el ds , als o a ve ra ged for th e 3· ye a r t i me period,
wer e 5,44 3 kg/h a f or t he 20 em r ow sp a c in g a nd 5 ,914 kgjha for the 10 em r ow
s pa cing . Thu s , bet te r weed c on t ro l and h i gher y ie l ds wer e obt a i ne d with the
wheat pla n t ed in na r row er ro ws .
Studies were t hen i n i ti a t ed i n 198 8 t o exam i n e whe at pl an t ed in 10 cm rows
co mpar ed t o wheat planted i n 15 cm r ows . Coupl ed wi th th e s e st ud i es we r e fi ve
differ en t he rbici de prog r ams and t wo dif fe ren t ni t r ogen a ppl ica tio n re gim e s .
Here , a single nitrogen app lica tion of 90 kg/ha applied ea rl y April was c ompar ed
to a sp li t app lication of 67 kg/ha. a pp lie d ea rly Mar ch pl us an add iti ona l 6 7
kg/ha applied earl y April. Wheat y i e l d data ave rage d over the 2 yea rs f ou nd no
diffe rences between the row spacings. Here , whe at y i el d s were 4,5 83 kg/ha f or
the 15 era row spacin g and 4, 650 kg/ha f or the 10 em r ow s pacing. Wheat yields
f or th e nitrogen treatmen ts va ried considerably. The s i ng l e nitrog en tr eatme nt
average d 4 .328 kg/ha for the z -yeer stud y , while t he s plit applica tion yi e lded
4 , 850 kg/ha .
From 1989 to 1990 , a nother se ries of f i el d stud ies c ompar ed n t tr ogen r a t e s
(67,90 and 11 2 kgjha) app li ed al on e , wit h t hife ns ul f u ro n, or wit h t h if en sul f u ron
pl u s surfa ct ant. These appl i cat i on s we r e made ea r l y Ma r ch and compare d t o late
Mar ch app lic a t i on s. Wheat yield da t a aver aged ov e r t he 2 -year stu dy f ound a
pos i t iv e ef fect f r om t he her bi cid e tre a t ment s whe n appl i ed ea rly Mar ch. On th e
other ha nd, whe a t y ie l d s de cre a s ed, par ticul a rly with th e t h if en sul f u r on plu s
s ur fa c t an t plu s n it rog en tr ea t ment, wh en a ppl ie d late March.
lIAssoc. Pr of . , Ag r l c . Ex p. St n . . Agron. Dept. , Unlv. of MD. ,
College Pa r k , MD 20 74 2 .

132
TERBACIL FOR CONTROL OF HENBIT AND COMMONCHICKWEED IN
ESTABLISHED AND SEEDLING ALFALFA
D.O . Ga n s ke l a nd E.5 . Hagood 2
Field t ria l s were establi shed i n 1988-9 0 in Wes t Vi r g i n i a , Virginia , a n d
Haryl a n d t o ev aluate terba cil at r e du c e d rates fo r the cont rol of common
chickw ee d CStc Ha r l a med ia L. ) and henbi t. ( Lami um ampl exic aule L.) i n
seed l i ng and esta b li sh e d al f alfa .
He r b ic ide trea tments were appl i ed i n wa t e r to 6 X 12 or 6 X 25 fo o t plots
usin g fl at fan s p ray tip s mount e d on a c omp r e s s e d air plot spra y er ca li br a t e d
t o de l ive r a se t v o l ume of wate r .
Four ra t e s; 0.20, 0. 27 , 0.40, and 0.60 Lb s ai/a, of ter bacU herbicide
were appli ed at two timin g s , l ate fall and l a t e winter.
Al l treatments o f terbacil a p p lied at bo th timin g s co n t r o lle d h e nbi t . A
r a te o f 0 .27 Los a i/ a was neces s ar y t o co ntr o l common c h ick we e d in the fa l l
a n d a r a t e of 0.40 lbs ai /a was nee ded to obt a i n c ontro l i n l ate wi nter. In
ge ne r a l , a s th e rate of t erba cil increased the co ntro l of h en bit and common
ch ickw e e d in cr e as ed irr es p e c t i ve of timing. See d ling a lfalfa injur y
incr e a s e d a s the rate o f terb a c i l incr eased; however , all rates had
acce p t ab l e cro p injur y ra tin g s of less than 18%. There were s i mi l a r crop
injury r a t i n g s f rom f all a pp li cat i on s vers u s late wi n te r applica tion s wh e n
compa r ing equa l r a t e s of terbac i l .
IDev e l op ment Repres ent a ti ve , Agricultural Produc ts De p a r t me n t ,
E. l . d u Pon t de Ne mou r s a nd Comp a ny , Win cheste r, VA 22601 .
l ASsoc La t e Profe ss or, Depart me nt of Plant Path o lo gy , Phy s i o log y an d
u e e d Sci ence , Vi:g~~ ~ a Poly tec h nic Institute a nd St a t e Un ive rs i t y,

133
Control of Canada Thistle [Cirsium arvense (L.) Seop.]
on Highway Rights-o f-Way
- Or .
Why I'll never be out of a job in weed control.
W.J. Chism, S. W. Bingham , an d R.L. Shaver'
ABSTRACf
Canada thistle is an herbaceous. perennialweed increasingly being found on highway
rights-of-way in Virginia. It's prolific seed production and extensive rhizomes make it an
excellent invading species in disturbedsites. Spring herbicide treatments were chosen to
selectively control Ca nada thistle (Qiliwn = L.) Scop.) in tall fescue (f2l!~
L.) and trailing crownvet ch (~ Yl!ril!L.).
TALL FESC UE
Test plots at Staunton, VA comparedApril versus May treatments for Canada thistle
control. The best control of Canada thistle and turf qualitywere provided by triclopyr +
clopyra lid (0.63 + 0.21 & 0.94 + 0.32) and clopyralid (0.28 & 0.42 kg/hal. An ilizene
produced veryrapid growthreduction in Canada thistle initially (90%) but did not provide
adequate control after 2 months at this site. Treatment time did not influence Canada
thistle control.
Test plots at w ytheville, VA compared Aprilversus May treatmentsfor Canada thistle
control. The best control of Canada thistle and turf qualityat this site were provided by
2,4-D (2.8 kg/ hal, triclopyr (2.24 kg/hal , trlclopyr + etopyralid (0.63 + 0.21 & 0.94 + 0.32)
and etopyrali d (0.28 & 0.42 kg/ hal . Anilizene provided moderat e, but not adequate growth
reduction over the course of the experiment. April versus Mayapplication timingsdid nOI
appear to influence weed control.
CROWNVETCH
An experiment was conducted at Bland, VA to test the ability of anilizene to control
Canada thistle in trailing crown vetch. Anilizene has provided inconsistent control of
Canada thistle over the past three years. Control of Canada thistle was not adequate at this
site.
CANADA THISTLE BIOlYPE S
Several authors have described four distinct biotypes of Canadathistle foundin the U.S.
and Canada. Upon examination we determined that our test sites over the past three years
have different biotypes present in them.
Anilizene is thought to act as an inhibitor of
photosystem n. Our work with an SF-lO fluorometer indicates that our biotypes have a
differential response to atrazine. However, the same work indicatesthat anilizene does not
influencewhole leaf fluorescence and did not inhibit PS n. Therefore, the inconsistencies
we are experiencing in controlling Canada thistle may be due to biotype differences in
herbicide sensitivity.
'Research Assoc. Prof . & Lab Spe c., Dept. of Plant Path ., Phy., & Weed Sci., Virginia
Polytech. Inst, and State Univ., Blacksburg, VA. 2406 1-0331

134
GIANT FOXTA IL CONTR OL WITH HERB ICIDES APPLIE D TO SOIL WITH AND
WITH OUT SURF ACE RESID UE
Arthur E. Gover. Larry J. Kuhns.and Gregory T. Lyman 1
ABSTRACT
As panof a cooperative project with the Pennsylvania Department of Transportation, 13 herbicide
combinationswere appliedto an area known to have high giant foxtail ~!llbm. Hemn .) pressure as
well as an accu mulation of surface plant residue. The herbicides includ ed broad spectrum, root abso rbed
herbicides, as well as low-solubility herbicides that work.primarily at the soil surface on gcnninating seeds
and seedlings. TIlCSe herbicides were applied to plots with and without surface residue to determine if the
residue would reducelhe activity of the herbicides. Combinationsof these two types of herbicidesareoften
used under guiderails for lOWvegetation control with theassumption that the low-solubility materials
provide longer activity near the soil surface than the more soil-mobile broad spectrum herbicides.
The herbicides applied were imazapyr, sulfcmeturon methyl. brcmacil. tcbuthiuron. two rates of
diuron. oryzal in.pcndimcthalin, simazinc. isoxaben. metolachlor, oxyfluorfen. and glyphosat e.
Glyphosatewas added with each herbicide and applied alone to thecheck plots to eliminate winter annual
weeds present at application. The applicationrates arclisted in Table I. TIle treatments were applied April
6, 1990 to an area that had been in a no-till rotation of com-oats-fallow for almost 20 years. The application
equipment was a C0 2 powered hand-held sprayer. applying 1741/ha at 2m kPa with Spraying Systems
8004fiat fan nozzles. The experimentaldesign was a randomized complete block with a split-block
treatment arrangement and three replications. with 1.5 by 9.1m herbicide treatment plots. 4.6 by 19.8 m
residue plots. and 1.5 by4.6 m herbicide by residue sub-plots. Surface residue was removed from the roresidue
plots with a tractor mounted York rake. Visual ratings of percent giant foxtail cover were taken
June 29 and October 9. 12 and 26 weeks after treatment (WAT), respectively. An application of 0.56 kg
ai/ha0(2,4- D was made July 6 to remove broadleaf weeds from the experimental area.
When the data was subjected to analysis of variance. the effect of residue wasfound to be
nonsignificant for the June 29 rating (p=O.42),and nearly significant for the October 9 rating (p=0.09).
'Theinteraction between herbicide and residue treatment effects was not significant June 29 (p--o.18), but
was highly significant October 9 (p=O.OCXm.Giant foxtail cover ratings were lower for all herbicides
when applied to bare soil (fab le 1). lmazapyr, isoxabcn, and cxyfluorfen showed the greatest difference in
giant foxtail cover between the two surface conditions. with a 32, 50. and33 percent difference,
respectively, between bare soil and residue plots. Giant foxtail cover in plots treated with sulJometuron
methyl , the high rate of diurcn. and pendimethalin were very similar between the two surface conditions.
Herbicide treatment effects. averaged over soil surface conditions, were highly significant, andall
treatments had significantly less giant foxtail cover than the glyphosate-onlycheck, which wasrated at 62
and 87 pcrcent 12 and 26 WAT, respectively. Sulfometuron methyl, the high rate of diuron, pendimethalin.
bromacil, rebuthiuron, andoryzalin providedexcellent giant foxtail control. The 26 WAT cover ratings for
these treatments ranged between 2 and 13 percent. The low rate of diuron, simazire, metclachlor, and
imazapyr plotshad less than 10perccntgiant foxtail cover when rated 12 WAT, but at 26 WAT these
treatments ranged between 22 and 41 percent giant foxtail cover. Iscxaben andoxyfluorfen did not provide
acceptablecontrol of giant foxtai l,as both were rated at 31percent cover 12 WAT; and47 and 58 percent,
respectively,26 WAT.
Under the conditions of lhis study, the broad spectrum herbicides bromacil, dluron. sulfometuron
methyl. and tebuthiuron provided season long control of giant foxtail andwould nor needto becombined
with low solubility herbicides such as oryzalin and pendimethalin. Oryzalin andpendimethalin could be
combined with broad spectrum herbicides that have little or no residualactivity to control existing vegetation
as well as weeds such as giant foxtail, andreduce the possibility of off-site movement which can occur
with the broad spectrum residual herbicides used in this study. Their use would be limited though, by their
reduced spectrum of control.
ISr. Research Technologist, ProfessorofOmame ntal Horticulture. :mrlPm ip ('l A"ciC'ta nt -r-s, .. o..~~~ ,. 1..__ :_

135
TABLE 1: Percentgian t foxtailcover present in treatments appliedApril 6, 1990, and rated June
29 and October 9, 12 and26 weeks after treatme nt. Values for 12 WATand themeanfor 26 WAT
arethemeanof six observations, andthebaresoil and residuevalue for 26 WAT arethe meanof
threeobservations.
GiantFoxtailCOver
26WAT
Treatment ApplicationRate 12WAT mean baresoil residue
(kg.Oh.) (%) (%) (%) (%)
1. imazapyr + glyphosa te 0.84 + 0.56 41 25 57
2. sulfomeruronmethyl + glyphosate 0.21 + 0.56 0
3. bromacil+ glyphosate 4.48 + 0.56 2 16
4. tebuthiuron+ glyphosare 3.58 + 0.56 15
5. diuron + glyphosate 5.60 + 0.56 22 12 32
6. diuron + glyphosate 11.2 + 0.56 0 4
7. oryza lin + glyphosa te 3.36 + 0.56 13 19
8. pendimethalin+ glyphosate 4.48 + 0.56 0 2
9. simazine + glyphosate 4.48 + 0.56 32 25 38
10. isoxaben + glyphosate 1.12 + 0.56 31 47 22 72
II. metolachlor + glyphosate 4.48 + 0.56 32 23 40
12. oxyfluorfen + glyphosate 0.90 + 0.56 31 58 42 75
13. glyphosate 0.56 62 87 85 88
Significance Level (P) 0.000 1 0.0001 0.0007 1 Coefficientof V ariation (%) 97 47 29
l.s.d. ( P~0.05) 12 16 14
11The significancelevel of the interactionbetweenresidue and herbicidetreatmenteffects.

136
MEYER ZOYSI AGRASS REGROWTH AS INF LUENCED BY HERBI CI DES
P . H . Dernoed en 11
ABSTRACT
Est abl i s hme nt of Meye r zoys i a gras s (Zo ys i a iaponic a St e ud .) from veg e t a t ive
plu g s gene ral ly r equ i r e s a minim um o f thr e e g r owi ng eee ec n e r wher e as, e st a b l i s h­
men t f r om sprigs r e qui re s about two gr owi ng se a sons . The o b j e c tive of this s tu d y
was to de t erm ine if esta blishm e nt fr om regro wt h o f h arve s t ed Bod c oul d be
ha s t en e d b y herb ici de s t hat r ed u c e weed compet iti on.
Meye r zo ysiag ra s s wa s es t a b l is he d f r om pl ugs at Si l ve r spri ng, HD i n 19 8 3,
a nd the mat ure st and was har vested in Aug 19 88 . On 10 Apr 198 9, th e area was
li ght ly roto tilled a nd t he si t e was se pa r a te d int o two ar e a s. Ar e a I was han d
ra ked to remove al l l o o s e ne d plant debris; wher eas , Area I I was not raked and s od
rib bons and deb ris were all owe d t o r ema i n i n p l a c e . Both are a s were rolled , and
herb i cide s wer e app lied over p rim ari ly ba reg round in Area I an d ba regrou nd plus
plan t debris in Ar ea II. Plots were 5 by 10 ft a nd a r rang e d in a random ized
compl ete block with either four (Area II) or fi ve (Area I ) rep l ication s per
tre a tment. The he rbicides (di thiopyr at 0.5 Ib /A; pendim etha lin a t 3 .0 I b / Ai
prodiamine at 0.65 Ib /A i DCPA a t 10 .5 lb /A ; oxadi azon at 3.0 lb / A; fenoxapr op at
0.3 5 l b / A and qui nc lo ra c at 1. 5 I b/A) we r e app lied at xec ommende d times in 50 gpa
:it;:g e~S~ ~om ~~;~c~~~a~p;::edt:~k l~~x~~ NW/l~~O 2 f~t~~A 2;fJU~~S 1 ~:~, :~~f ~ ~t ~~~ ;
13 Jun e, and 10 Ju ly 1990. Plot a r e a cov e r e d b y weeds or zoysiag r a s s was
det er mi ne d visua lly on a 0 to 100\ scale . All d ata were sub jected t o ana lysis
o f v a r i ance an d sig nifica nt ly d i ff e r e nt mea ns wer e separ a t e d at P = 0.05 by
Du nc a n 's mul t i p l e r a ng e t e s t .
19 89 Re s u l t s
Carpetweed (~ v e r t i c i l l a t a L.) . an d smooth c r ab g rass (Digit a ria
i sc ha e mum ( Sc hr e b.j Muhl . ) wer e the p rim ary weed compet i to rs . In Area I ,
c ar pe t wee d was eff ecti vely cont rolled by al l p r eeme rgence he rb i c ides , bu t no t by
fenox ap rop o r quinclorac. Crabgr ass was reduced significant ly b y a l l treatm e n t s .
Exce pt for pendime th alin a nd p rodiami ne (22 -23\ zoysi a cov e r), most her b i cid es
(24 - 34\ zo y s i a c o ver ) enhanced t he c ompe t i t i v e ne s s of Me y e r s i g n i f i c a nt l y , when
comp a r ed to untreated pl ot s (13\ zoysia cover) .
I n Area II, o nl y pendim e t h ali n. p rodiamine and oxadi azon had provided
effe ctive preemergence carpetweed control; wher eas, al l herbic id e s had p r-ov Lde.d
exc e l l ent crabgr ass control. By 13 s e pt it was e v i de n t t h a t al l h er bi ci d e s (5B ­
69\ zoys i a c o v er ), e x c e p t qui nc l o rac (4B\ zo y s i a cove r), wer e a s s o c i a t e d with a
s igni ficant i nc r e a s e i n Meye r c o ver wh e n c ompar ed t o u ntrea t ed p lo t s ( 3 1\ zo y s i a
co ver ) . Th is i ncreas e i n zoy siagras s c ov er was a ttri b ut e d to t he r e d uct ion of
c r a bg r a ss c ompe t i t io n accord e d b y t he her bic ides.
199 0 Resu lt s
He rbicide r at e s were r e d uce d in 199 0 an d all p re e mergence herb i c i d e s
provid ed excellent c r a bg r a s s c on t ro l in Area I . Fe nox a pr op a nd quinclo r a c h ad
re duced cr ab g r a ss, but t he leve l of c o nt r o l was only 73\ . Her bic i de us e in Ar ea
I was a s s oc i a t e d wi th signific a ntly grea te r zoy siagrass co ve r r a t i ng s (92 - 97 \)
when co mp a.re d to un treated plots (BB\ c over) o n 9 Oct 19 90.
I n Area II , all herbi cide s prov ided exc e llent crabgrass co ntrol beca use
zo y s i a g r a s s c o ver was v e ry h igh in s p r i ng 1990 a nd weed compe t i tion was the r efor e
not a s se ve re as it was in Ar e a I . Zoysiagr a s s co ver was sig n i f i c a n t l y highe r
(98 -100\ cover) in her bicide -t r e at ed p lo ts t ha n untreated pl ot s (95\ cov e r) o n
9 Oct 19 90.
Re s ult s o f t h i s stu dy s howe d t ha t herb i c id e use sig ni f i c a nt ly red u c e d wee d
co mp e t i t io n a nd a s si s t ed in s pe e d i ng zoy siagrass gr owth. None of t he herbi c ides
was p hyto t oxi c , a nd none wa s a ss oc iated wi t h a r e d u ction in t he g rowth or

137
ras
EFFECf OF APPLICAnON TIMING ON 11ffi ACTIVITY OF PLANT o a owra
REGULATORS APPLIED TO TALL FESCUE
Arthur E. Gover. Thomas Lwarschke,
and Greg ory T. Lyman"
ABSTRACf
Previous research at Penn State2Jhas suggested that different plant growth regulators (POR's)
have different periods of peakactivity between the breaking of dormanc y and seedhead emergence
on unmow n tall fescue~ arundina cea Schreb.). This study wasinitiated as part of a
cooperative research project with the Pennsylvania Department of Transportation to determine if
different plant grow th regulator combi nations demonstrated differe nt activity peaks within the premow
application window.
MATERIALSAND METHODS
The study site was seeded in the spring of 1987 to a blend of' Cimmaro n', 'Bonanza ', and
'Olympic' turf type tall fescues. Prior to 1990. the area received 60 kg of fertilizer nitrogen/he
annually. and was maintained at a height of 9 em. The experimental design was randomized
complete block with a split-plot treatment arrangement with three replications. Each 5.5 by 4.6 m
application timing whole plot was divided into six 0.9 by 4.6 PGR treat ment sub-plots. The
application times were April 23, April 27, May 2, May 8, and May 14, 1990. The PGR treatment s
were mefluidide (N 2,4-dirnethyl- S-([lrifluorornethyl) sulfonyl] amino] phenyl] acetamide) at 420
g ai/ha; chlorsu lfuron (2-chloro -N -[[4-methoxy-6-methyl-I,3,S-lriazin-2-yl) amino] carbony l]
benzenesulfonamide) at 26.2 g ai/ha; mefluidide plus chlorsulfuron at 210 plus 13.1 g ailha; a
commercial premix of imazethapyr and imazapyr31( (±)-2-[4,5-dihydro-4-methyl-4-( I­
methylethy l)-S-oxo-IH -imidazo l-2-yl]-S-ethyl-3-pyridi necarbo xylic acid and (±)-2- [4 ,S-dihyctro­
4-methyl-4-(l- rne'h ylethyl)-S-oxo- IH -imidazol-2-ylj -3-pyridi necarboxylic acid), at 98.4 and 3.8
g ai/ha; mefluidide plus the premix of imazethapyr and imazapyr at 140 plus 49.1 plus 1.9 g ai/ha,
respectively; and an untreated check. The treatments were applied with a CO2powered hand held
sprayer delivering 16111haat 207 kPa using Spray ing Systems 8002 flat fan nozzles. All PGR
treatments included dicamba (3,6-dichloro-2-methoxybenzoic acid) at 0.56 kg ailha and a spray
adjuvantv at 0.25 % v/v. Initial visual ratings of turf color and turf quality were taken May 15 for
the April 23 applications; May 29 for the April 27, May 2, and May 8 applications; and June 5 for
the May 14 application. All plots were visually rated for percent seedhead suppression, turf color,
and turf qual ity July 2 Seedhead suppressio n ratings were based on the untreated check within
each application time whole plot Turf colo r and qual ity were rated on a 0 to 9 scale, with 9 being
ideal, 0 dead turf, and 5 acceptable. When the data was subjected to analysis of variance, the
interaction between application time and PGR treatments was highly significant for all dependent
variables.
RESULTS AND DISCUSSION
Initial color ratings for mefluidide at 420 g ai/ha were acceptable and consistent for all
applications. Turf quality ratings decreased for later applications as the turf grew taller with a more
uneven canopy compared to other treatments. ~h.e:ad..'\IPJ.m:~.'i.'i i.m" 4ta1 j JlF-t" Ja..~ r..Ill)"'" ",rot!"
goodto excellem for appli cations made April 23 and 27. then decreasedsignific antly for the M ay 2
1/ St. Researtb i ecbno\ogisl, Prof essor of iurfgrass Science, and Projec t Assistant. 1be Pennsylvania State
University.
11Gover, A.E.• TL. Watschke, G.T. Lyman. 1990. Effect of Application Timin g on Embark and Esco rt
Combinations. Roadside vegeiauon Management Researc h Report - Fourth Year Report, Report NPA 90-4620
+ 85.08. Availab le from National Technical Informatio n Service. Springfie ld. VA.
31Event, American Cyanimid Company , Wayne . Nl .
41Cidckick Il, lLB Inc.• Vero Beach, A..

138
application. Turf color and quality ratin gs taken July 2 followed the same trend as the seedhead
suppress ion ratings . The color decline appeared to be due to the begin ning of leaf senescenc e, and
the quality decli ne was due to increas ing prese nce of seed heads and an uneven canopy. and less
favorable color ratings.
Chlorsulfuro n at 26.2 g ai/ha showed an improved initial color rating betwee n the Apr il 23 and
27 applica tion dates, then no change with subsequent applications. The initial quality ratings were
more varied, thou gh accep table , and did not show any overa ll trend . Seedhea d suppression was
nor accep table for the April 23 and 27, and May 2 applications, but improve d to accepta ble levels
for the May 8 and 14 app licatio ns. Whe n rated July 2, turf color and quality were con sistent and
acceptab le for all application dates . The combina tion of mefluidi de and chlorsu lfuron , prod uced
barely accepta ble initial color ratings for the April 23 and 27 applica tions. Turf color ratings
improved with the later applications, but this comb ination consistently rece ived the lowest initial
turf color ratings . Initial turf quality relative to the other treatments changed from worst rated for
April 23 to best rated for May 14, despite a change of on ly 6.3 to 7.0. July 2 ratings of seed head
suppression, turf color, and turf quality were good to excelle nt for all application dates.
The commerc ial premix of imazethapyr and imazapyr showed initial turf color and turf quality
ratings between 6.3 and 7.0 for all application dates. Seedhead suppress ion was good to excellen t
for all appl ication date s, as was turf color and turf quality when rated July 2. Add ing mefluidide to
the premix of imazethapyr and imazapyr prod uced initial turf color rati ngs that were cons istently
lower , though acceptab le, than the premix alo ne. Initial turf quality differences betwee n the two
treatme nts were not apparen t. Meflu idide plus the prem ix consistently prov ided excellent seedhead
suppression, and was amo ng the highest for Jul y 2 color and quality ra tings .
The untreated chec k received the highest initial turf color ratings for each application date. The
initial turf quality rating fell dramatically to unaccepta ble levels after the Apri l 23 applicatio n due to
the uneven appearanc e resulting from unchecked growt h. Seedhead pressu re was different
betwee n the check plots, but was alway s rated 0 perce nt suppressio n. July 2 ratings of turf color
were barely accepta ble as leaf senescence was occurring , and turf quality was unacceptable due to
the prese nce of seed head s and uneven canop y growt h.
Under the conditio ns of this study, mefl uidide showe d greater activity on tall fesc ue in earlier
applications. Whe n combi ned with a reduced rate of chlorsu lfuron, early app lications caused more
discoloration , but seedhead suppression was improved. Similar results were found when
mefl uidide was combi ned with a com merc ial premix of imazethapyr and imazap yr, though
improveme nts in seed head suppress ion were not as pronounced as with chlorsu lfuron.

139
TABLE 1: Visualratingsof rurf color, turf Quality, andpercentseedhead suppression forPGR
treatments appliedat five differentdates to tall fescue. Turfcolor and turfquality ratings wereon a
oto 9 scale, with0 indicatingdead turf, and9 being ideal.Seedhead suppression was rated based
on the untreatedcheck foreach applicationdate. Eachvalueis themeanof three observations.
3-4 WAT July 2 1990
Application Tun Turf Sdhd . Turf Turf
Dale Products
Rate
Co lor Quality
Sfo-~f ~u~) . (0-9) (6=9)
?o'!9)
4/23 mefluidide 420 7.0 7.3 90 7.0 7.3
4/23 chlorsulfuron 26.2 5.7 6.7 67 7.0 6.7
4/23 mefluidide + chlorsulfuron 210 + 13.1 5.0 6.3 93 7.0 7.7
4/23 imazethapyr + imazapyrt/ 98 + 3.8 6.3 7.0 83 7.0 7.0
4/23 mefluidide+ imazethapyr+ imazpyr 140+4 9+ 1.9 5.3 6.7 93 7.0 7.0
4/23 untreated check 8.0 7.3 0 5.0 4.3
4/27 mefluidide 420 6.7 5.7 85 6.3 7.0
4/27 chlorsul furon 26.2 6.3 6.3 48 7.0 7.0
4(27 mefluidide + chlorsulfuron 210 + 13.1 5.3 6.3 92 7.0 7.7
4/27 imazetha pyr + imazapyr 98 + 3.8 6.3 6.7 92 6.7 7.3
4/27 mefluidi de + imazethapyr + imazpyr 140 +4 9 +1. 9 5.7 6.7 92 6.7 7.3
4/27 untreated check 8.0 4.7 0 5.0 4.0
5/2 rre fluidide 420 7.0 5.3 8 5.0 4.0
5/2 chlorsulfuron 26.2 6.3 6.7 65 7.0 6.3
5/2 mefluidide+ chlorsulfuron 210 + 13.1 6.0 6.7 83 7.0 7.0
5/2 imazethapyr+ imazapyr 98 + 3.8 6.3 6.7 87 6.7 6.7
5/2 mefluidide + imaze thapyr + imazpyr 140 + 49 + 1.9 6.0 7.0 95 7.3 7.7
5/2 untreatedcheck 8.0 4.7 0 5.0 4.0
5/8 mefluidide 420 7.3 5.3 13 5.0 4.7
5/8 chlorsulfuron 26.2 6.3 5.7 80 7.0 6.7
5/8 mefluidide + chlorsulfuron 210 + 13.1 6.3 6.3 90 7.7 7.3
5/8 imazethapyr+ imazapyr 98 + 3.8 7.0 6.3 83 6.3 6.3
5/8 mefluidide+ imazeth apyr + imazpyr 140 + 49 + 1.9 6.7 6.7 90 7.0 7.3
5/8 untreatedcheck 8.0 4.3 0 5.0 4.0
5/14 me fluidide 420 6.7 4.7 55 5.7 5.3
5/14 chlorsulfuron 26.2 6.3 6.3 83 7.0 6.7
5/14 mefluidide + chlorsulfuron 210 + 13.1 6.0 7.0 95 7.3 7.0
5/14 imazethapyr + imazap yr 98 + 3.8 6.3 6.7 97 7.0 7.7
5/14 mefluidide+ imazethapyr+ imazpyr 140 +49+ 1.9 6.0 6.3 93 7.0 7.0
5/!4 untreated check 7.7 4.0 0 5.0 4.0
Signi fican ce Level (P)
cv. (%)
0.042 0.00 1 0.001 0.001 0.001
5 10 13 6 8
LSD (P=0.05) 0.6 1.0 14 0.6 0.8
1/A commercial premix , Event, American Cyanim id Company, Wayne, NJ

140
eGA 163935 ALONE AND IN COMBINATION
WITH OTHER GROWTH REGULATORS IN TALL FESCUE 1
2
ADRIAN J . ENACHE and RICHARD D. ILNICKI
ABSTRACT
The experimenta l turf growth regu lator, eGA 163935, was
evaluated in two studies at the Adelphia Research Center, Free ho ld,
N.J. The objectives of this research were to determine if th e r e
were differences in turf growth regulation and t urf response (i)
when eGA 163935 was applied alone and in combination with three
other growth regulators, and (ii) when sequential applications of
eGA 163935 were used .
All treatments were applied to tall fescue (Festuca
arundinacea Schreb.). For the first study, treatments were applied
at turf green -up (April 12, 1990) and included eGA 163935 at two
rates (0 .6 and 0 .8 kg ai ha" l), mefluidide, maleic hydrazide, and
primisu lforon alone and in combinations with CGA 163935. Treatments
for the second study were applied April 12 and May 23, 1990 and
included CGA 163935 at four rates (0 .2, 0 .4, 0 .6 , and 0 .8 kg a i
ha "} applied alone at turf green-up and followed by a second
application of various CGA 163935 rates. Each study consisted of
three replicates in a randomized block design. Turf color and
injury were rated and number of seedheads counted periodicaly in
each study. In the second study turf height and fresh weig ht of
clippings were recorded also .
No injury to the turf was observed at two weeks after
treatment (WAT) with CGA 163935 applied alone . Combinations with
high rates of mefluidide and primisulfuron caused temporary turf
injury. All CGA 163935 applications, either single or split,
significantly reduced turf height compared to unmowed check;
however , no differences between the mowed check and all treatments
resulted. Sequential application of CGA 163935 at 0 .4 and 0.8 kg
ai ha· 1 seemed to be the most effective in reducing t he t u r f height .
CGA 163935 applied a l on e reduced the number of seedheads compared
to unmowed check; no reductions were observed compared to mowed
check . Hig her rates of CGA 163935 with mefluidide and primisulfuron
were more effective than lower rates wh i l e the combinations with
maleic hydrazide wer e more effective at lower ra tes . Single
application of CGA 163935 did not reduce fresh weight of clipp ings.
Sequential application reduced fresh weight at 10 WAT. At 14 WAT,
fresh weights of all, single or sequential, applications of CGA
163935 were lower than the unmoved check a nd simi lar to that of the
12 times mowed check .
This indicat ed that either single or sequential applications
of CGA 1639 35 wer e capab le to replace 10 to 12 turf mowings during
a season .
, New Jersey Agric . EXp. Stn. Publication No. J-15 173 - 1-90.
2 P""c: l'tc:c.n('" ",nn P""c: Pl"'nf" W""""n~,..i ,...pl=:np("!t"ivplv _ (',...on ~,.. i.

141
RESPONSE OF SEVERAL TURF GRASSES TO CGA-I63935 .
D. B. Vitolo, R. Brooks. S. W. Pruss and P. J. Porpiglia 1
ABSTRACT
inh i bit i~:C-~J:;~S~f=;:~~~~~ti~:~ ~;~~~j~~ead~:~ for vegetative
Effective use rate s ofCG A-163935 vary from 200 to 1000 g:.:fha. Factors which
~~U~~~:t[~~eoitd~~rr~ :i~8:iti~~ : (fs~i~~~~nh~~b~e~n~r~~d~h iC~;~~~~~~PP roxi _
mately 50% growth inhibit ion for four weeks.
CGA-163935 was evaluated in 1990 for cool-season turfgrass inhibition in field tri als
~r1=~ ~::~~Y~~~Jf~~~~ &gr~~:fes~erf~~t),~~e:i~ded
ryegrass (YiliJlm==L ). and Kentucky bluegrass (flla IlIllill!SisL) .
CGA -163935 at 1000 g aifha applied to tall fescue reduced clipping fresh weights by
50% over a six week period. An 800 g ai/ ha rate reduced the number of mowings by 50%
over a seven week period. This single 800 g ai/h a application provided mowing reductions
comparable to two applicat ions of either 400, 600, or 800J ai/ ha apElied 30 days apart.
~:i~h:tf~di~~~~1 R:~a;~~~~~f~~~tz
:~~:S ~~d:C:d\~~:e7~
eight week peri od following two applications of 800 g aifi;a applied at 30 day intervals.
Augu s t~~e~~:(St~~~~~~h~~o~-[\t~:'r ~~~~b~hi~~~~t(r:~lfu ~nn~iatum
Fluegge), and Bermudagrass (~~ [L ] Pers.}for general turfgrass inhibition
and as an edging compound.
Single applications of CGA-163935 at 800 g ai/ha reduced the numbe r of mowings
of St. Augustinegrass, bahiagrass, and bermudagrass 66%, 57%, and 33%, respectively, for
a period of seven weeks.
Turfgr ass toler ance to CGA-163935 has been excellent. Th ree successive years
of 3000 g ai/ ha per year, applied in 1000 g ai/ ha increme nts during the growing season,
have shown no adverse effects on tall fescue. Three successive years of 4000 ~ ai/ ha ap-
C~h~~~~~gi~ /l;~n~ r~ih~ t~;;li:d~~:80n: ~~h~rs~c~~f:~~~~h~~~\lFo: ~~~~~e~~e
effects on Kentucky bluegrass or common Bermudagrass for one and two years, respectively.

142
SUMMARYOF THE BAS 514 00 H EUP
PROGRAMRESULTS ON NORTHEASTERN TURF
Ric har d R. Eva ns l , Greg Roman , Willia m Sc iarappa
ABSTRACT
BASF Corporation c ondu c t e d an EUP program in 199 0 wi t h BAS
5 14 00 H for the control of gras s and broadleaf weeds in turf.
The national program a l l owed the usage on 107 hectares of turf i n
a l l a r e a s of the Unit ed state s . In the Nor t h e a s t, app lic ations
were made in Maryl and, Delaware , Virginia, Pennsylvani a, New York ,
New Jer sey and Ohio . Over 40 trials were condu cted on golf
cour s e s , commercial turf , and s por t s turf at 0.2 to 1.6 hectares
p er site . Applic ation rates r anged from 1 .7 to 2.2 5 kg /hectare
app l i ed postem er genc e i n 24 t o 220 l ite rs of water per he ctare.
The turf spe ci e s pr e s ent at each site were usuall y 2- and 3-way
mix t ure s of p erenni al ryegrass (Lolium perenne L . ), Ken t u c ky
bl u e grass (Po a p r at e ns is L .), t all fescue (Fe stu c a a ru nd ina c e a
Sc h re b. ) and f i n e fes c u e (Fes t uca s p eci e s ) or be rmud a gra ss
(cyno d on da ctyl on Pe rs . ) or b ent grass (Ag r o s t i s p a lu str i s Huds.) .
App l ica t i on d at e s r a ng ed fro m June 5 to Aug u s t 15 f or the initi a l
app lica t i on with subsequ en t a pp lica ti ons, if n e ed ed, mad e
app rox im a t e ly 30 da y s la t e r . Use rs indi c at e d th eir e val ua t io n of
t h e co nt r o l of ea ch wee d b y c he c ki ng th e ap pr op r i at e box l abel l e d
exce l l e nt , g ood, fair or po or .
Injur y t o tu r f was ve r y lo w to non e . Goo d to exc e l l en t
con t ro l of s mooth c r ab grass (Dig it ari a i s chae mum Sc hr e b . e x
Sc hwe i g. ) , large c ra bg rass (p igit ari a s anguin ali s L .) , y ellow
f ox t a i l (Setari a gl au c a L.), d an d elion (Tara xa cum o f f ic i na l e
Web er), veroni c a spec ies , bu ckhorn plantain (Pl antago la nceol at a
L .) a n d white clo v er (Trifolium r ep ens L .) was obtained at the
rate s used . Some wee ds not controll e d we r e br oadl ea f pla ntai n
(Pl antago major L .), pr o s t r a t e kn ot we ed (P ol ygon um a y ic u la r e L .),
mou seea r chick wee d (Ce r a stium vulg atu m L.), goosegra s s (E l eu s ine
i ndica L .) and n i mb lew i l l (Muhl enb erg i a schr e ber i J . F . Gme l . ).
1BASF Corp or ati on , P . O. Box 13528 , Resea r ch Tr ian gl e Pa r k, NC
27709 - 3528

NUMBER OF LOCATIONS THAT RANKED THE CONTROL OF TURF
WEEDS WITH BAS 514 00 H
NUMBER OF LOCATIONS
RATE
Kglha DIGSPN SETSPN TRFRE u VERSPN TAROF" PLALAo°
--
E' G' F" P' E G F P E G F P E G F P E G F P EGFP
0.84· 15 1 2 1 4 1 1 1 12 2 1 1 3 1 - - 3 5 3 3 3 2 1 1
1.12 13 3 1 - 1 14 2 1 2 3 1 2 3 2 3 1
OXAST" •
E"GFP
- 3
PLAMA ' O
E"GFP
2 2
TOTAL 28 4 3 1 4 1 2 1 26 4 2 1 5 4 1 - 5 8 5 3 6 3 1 2
LOCATIONS
- 7 3 -27
*INFORMATION IS GROUPEO FOR DIGITARIA SPECIES (DIGSP), SETARIA SPECIES (SETSP) AND VERONICA SPECIES (YERSP)
...
w
• E _ EXCELLENT CONTROL
G • GOOD CONTROL
F . FAIR CONTROL
P • POOR CONTROL
•• WSSACO DES

144
BAS 5 14 H - APPROACHES TO S ELECT IV I TY AND EFFICACY
IN BENTGRA SS AND BLUEGRASS
Wi l l ia m J. sc t .are ppe -
ABST RACT
Fi e l d st u d i e s were conduc t ed in 19 9 0 wit h BAS 514 H (BAS F ­
quinc hloracj p ropo sed) i n order to improve e f ficacy against
bucxhoxnynar-rowkeef plan tain (Plantago lanceolata L . ] i n Kent uc k y
b lue g r ass (Pa a pra te nsis L.] turf a nd t o improve se lec t iv i ty in
Pe nncros s cre eping be nt g rass [Ag r os ti s pa l ustri s Huds . ] tur f wh i l e
co nt r o l l i ng h airy cr ab gras s (Di g i tar i a s anguina lis L. ] .
Contro l o f b uc kh orn plan tain i n b lue gr a s s with a s in g le
postemergence app licatio n of BAS 514 H at .38,.5 ,.75 o r 1 . a Ib s
ai /a pl US su r f a c t a nt (BAS 090 02 5 at 1 qtja] du r ing ea r ly Ju ne,
mid Ju l y or late Se pt ember ranged from ca. 30 t o 60 \:. seq uenti a l
a pp l ic a t ion s at l ow rat e s 30 da ys af t e r t he fi r s t s pr a y
s i gn i f i ca nt l y impro ved cont r o l at the mi d -summ e r peri od . s equential
a pp l i c a t io ns of BAS 514 H I 0 . 75 + .25 Ib s a i/ a , . 5 +. 5 l bs a i/a or
. 375 +.375 Ibs ai/ a] ach i eved ove r 90% con t r ol. No inj ur y occ ur r e d
at any t r eat me nt r at e to Kentuc ky bluegr a ss .
Contro l of ti llered hai ry crabg r ass i n bentg ra ss was r e l ated
to ra t e of BAS 514 H an d t he mowing he i ght . Lower cu t cra bgrass was
con t rol le d mor e ea s ily an d high er rat e s provided bett er e f fi c ac y .
At . 38 lb s ai/ a, cont r ol r an ged fr om 70% [3/ 16 in ch cut ] to 52% [1
to 2 in ch cu t] . At .5 an d. 75 lb s ai/ a , co nt r o l ra nge d from 59% to
78% an d fr om 83% t o 93%, r e s pec t i vely . Sequen tial ap p l i cat ion s of
.5 l bs a i/a increased control at all ra tes and mowi ng heights t o
over 90%.
Be ntg r as s t ol e r a nc e t o BAS 514 H sh owe d a n i ntegr a t ed
r e l at ion sh ip o f r a te , mowing heigh t, and th e u se of a c he l a ted i r on
so urce c oup l e d with a l ow bur n , t i me d releas e, liquid nitrogen
fertili ze r . Shor te r mowi ng he i ght s a nd hi gher r at es decreas e d tur f
quality. At 7 days afte r trea tment , the unt rea te d bent gr a s s t ur f
was r at e d as 8 on a color /quality scale o f 1 to 10 . Quality of
ben tg rass t reated wi th BAS 514 H at .75 lbs ai/a a ver a ged 5.83 i n
the 3/16 inch put t ing green cu t, 6.50 in t he 5/16 i nch co l lar c ut,
7.17 in the .5 inch fairway c ut and 7.33 in t he 1 t o 2 in ch r oug h
c ut. At .5 a nd . 38 lb s ai/ a , qual i ty i mpr ov e d an d was rated
r e sp ecti vely a t 6 .33 a nd 6 .33 in the gr e en, 7. 33 and 8.0 in t he
colla r, 7.83 and 8 . a in t he fai rway a nd 7.33 and 7 .5 in the r ough .
The incl usion of t he iron chela te/ low burn fer t i l i ze r in to the .75
lb ai/a r a t e of BAS 514 H improved t ur f quality dr ama t i c a l l y t o
7 .17, 7.50, 7.67 and 7.67 at the inc reasing mowin g hei ght s.
Simi la r tr e nds were recorded 20 a nd 42 days a ft er i ni t ial
t r e atm e nt s. Si ngl e or se que nt ia l appl ica t i on s of BAS 514 H late in
t he sea son at .5 lbs ai/a + BAS 090 02 S s ur f a c ta nt , iron chelate
and l iquid N fer t i l izer sh owe d ex c e pti onal s a f e ty at a l l he i ght s .
1\ Field Development, AgriCUltural Chemicals, BASF , Nep tune , NJ 07753

145
Abstract
TURP GRAB B ROOT L ENGTH, STRENGTH , AIm HASS RESPONSE TO QUINCLORAC.
R. D. s terling, D. R. ca r l s on , D. E. Dougherty .
Qui ncl o rac (BAS 514 ) is a n e xpe r imen tal h er bici d e bei ng
developed b y BASF for ea r ly posteme r gence c r abgra s s a nd br oa d l e a f
weed control in t u r f . Many dinitroanilin e s u s ed for pr e eme rg e n c e
crabgrass control in turf have delet erious effec t s on roo t growth.
Thre e sepa rate approaches were used to determ i ne whe the r qu i n cl or a c
inh ibited r o ot le ngt h , s t re ngt h , an d mass as comp a r e d to the
commercia l s tandard pe nd irne t ha li n.
A petri dish a ssay wi t h pre germ in a te d co r n was us ed to det er mi ne
if quinclo rac inh ibited r oot growth. Si lic a san d was t reat e d with
30 mis of dilute h e r b i c i d e so lution. Th e so lut ion co nc e ntrations
of quinclorac were appl ied at 2.0, 1.0, and 0 .5 ppm. Pe ndime t halin
was app lied at 3. a and 1. 5 ppm . Treatme nt s were r e p l ica t e d t hr e e
time s . Af ter twenty four hou r s , quin c l or ac inh ibited r oot gro wt h
14%, 3%, a nd 0% at 2.0 , 1. 0 , a nd 0 . 5 ppm , resp e ctive l y. Th e
pend imetha li n t reat e d s e ed l i ng s exh i b i te d 81 % inhibition at 3.0 pp m
and 58% at 1.5 ppm . Cor n see dl i ngs t r e at ed wi th p e ndi methalin h a d
swollen meristems, while the q u incl orac roo ts ap p eared normal.
To det ermine he rbicide aff ec ts on r o ot mass , for ty -two 0 .45
lite r pots were filled wit h a s a nd y l oa m s o i l a nd wate r e d t o field
capacity. Th e ba re soi l was spr a y e d wi th qu in clorac a t 2 .0, 1. 0 ,
a nd 0. 5 kg/ha, a nd wi t h p endimeth alin at 3 .0 a nd 1. 5 kg/ha . Each
t r e at me nt con taine d s even r ep lic a t i ons . Af t e r the soi l was
trea ted, a mixed sod of "x e n b.Iue ' b lu e g ras s/ 'Rebe l ' t a ll fe sc u e was
placed on the soil sur face a nd al lo wed to grow fo r f our months.
After four months, the ro ot mass was cu t b e low th e sod. The r o ot s
were then washed, dried and weighed. Bot h compo u nd s aff e c ted
turf g rass r oo t mass. Treatments wit h quin c l or a c re s ulted in a 19 ,
17, an d 15% dec rease in r o ot ma s s at 2 . 0 , 1 .0, a nd 0 . 5 kg/ ha,
r e s pe c ti v ely , wh i l e p end imeth alin resu lted in a 36 % decr e ase in
root mass at 3.0 kg/ha a nd a 32% de c rease at 1. 5 kg / h a .
To de termine tu rfgrass r oot s t re ng th , a fi e l d st u dy was
conducted using a dyname te r which measu re s t h e f orce re qu ir e d to
pUll a 929 emil sod piec e f rom t h e ground. The s o il sur f a ce was
trea ted with qui nclor ac a t 2.0, 1. 0, and 0 .5 kg /h a a nd
pe ndi met h a l in a t 3 .0 a nd 1. 5 kg/ha . Met al gr at es were then p lac e d
o ver th e tre at e d area . A mi xe d sod o f ' Kenblue 1 blue grass /
' Re bel' ta l l fescue was p l a c ed over t h e gra t es and all owed to gr ow
from October to Decembe r. When th e sod was pu Lf ed , qu i n cl or a c
treatment resulted in a 4, 3 , and 0% decrea s e a t 2.0 , 1. 0 , and 0.5
kg/ha respectively , whi le pendimetha lin r educed r o ot s t reng th by
36% a t 3.0 kg/ha an d 18% at 1.0 kg/ha .
Quin c l or a c ca u sed l it tle or no inhibition o f roo t l e ng th ,
s t r en gth, or mass in th e mixed turf c omp a re d to pendimethalin .
Further s tudies wi ll be con ducte d t o dete r min e t h e e f f e ct of
quinclo rac on other tur f spec ies.