Vol. 16—1962 - NorthEastern Weed Science Society

197
scale tests on 2 cOlJllllercial plaz:rt1nSs on heavy soUsbowed some initial
burning but later recovery. ' ,
, Apeopy planting at the st~te University ASr1cJ1t~al. and Technical
InetHlJte, at Farlldngdale has. re~e1ved allnUal wint~ tr'eatments, of diuron. "'
up to .4 pounds p~r. acfe ands1illa.Z~ne' up to 10 pOU%1~W per acre for suc.cess1ve
4 ye~e. The treat~nts were 1lIelii:~. ~n a. planting ot:,~,ed varieti,es. . ,',.
Tolerance to .the chemicals e.p,d ~ed.oontrol at .the v~ous rates have been
good: 'Results on commercial pliUltinSs usually have'been successful. Alt/;ieugh
there have been some reportl3 of uneven weed control anainjury t'o peOniesL[L
where granular sime.zine or, ditii.iOrihad been used. The rates were in the range
of 2; to 3 pound~ of. f11\1%'on' or 3 to; 4 pounds a.ctual s;t.ine per acre. Usually
injury has been due to uneven a,1sM-;bution of gran~e., Some of the cro~, "
injury may be due to a variation in the tolerance of,a.few of the mapy
varieties to simazine or diuron. Where simazil;le had. been used for 3 ;Ye$:t'Jf
011peonies, and: d.a1' lilies a redUct1.\lln in vigor was~. '
Soil type ,is one, of the fe.ctorlil apparently respQns1b.le for some, of the
inj141'y when herbic-1des are used at high rates.' W1:tQaJ:IYchemical herbic~~
growers should determine how loW.a :rJate they can use, On their crops and, s;t;W ,
get adequate weed control. RecolllDe&dedrates for l:LBhter soils are usuaJ.;lq
considerably lower than for heavier soils. Herbicides are selective and
should:be tested on a few plants ora variety befor~ lllitge scale usage.
Herbicides must be used at a safe rate and be evenlY !~pplied. I
The usera",
frequently need help in selecting the proper herbio:l.ae,calculating dosages,
and selecting proper application< equipment to avoid diseppointing results
from the use of herbicides.
Although large scole tests b.a,v.~demonetre,ted ci,~!lZ'iy that herbicides ,can
be used safely on some crops for one season, some growers of perennials I1a;ve
noted A reduction of growth after two or three seasons use of the same
herbicide; This e,ge,in eliJPhasizes the value of using'l9Wer rates alternating
with other chemicals and/or cultivation. ,. ' .
LITERATURECITED
1. Ahrens, J. F. 1961. Chemical control. of weeds in nursery plantings.
Conn. Agr. Expt. Ste.. Bull. 638:41p.
2. Bing, A•. 1960,. A comparis0p,ofsome herbicides in flo'jl'ering and corm
yield of gladiolus variety Friendship. NEWcC'14:148-155. , '..
3. Bing, A. 1961. 1960 gladiolus weed control sUDlllia.ry. N.A. Glad.:Lol.us '
Council Bull. 65:71-74.
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