Vol. 51—1997 - NorthEastern Weed Science Society

27
PERFORMANCE OF PREEMERGENCE TREATMENTS OF EXP 31l30A IN
WEEDCONTROL IN CONVENTIONAL TR.LAGE CORN
IP. C. Bhowmik, R. G. Prostak and M. K. Swarcewicz 1
ABSTRACT
Two fie14experiments were conducted at the University of Massachusetts Research Station
in South Deerfield, Massachusetts to evaluate the effectiveness of EXP 31130A in controlling
annual grass and broadleaf weeds in conventional tillage corn (Z&a~ L.). EXP 31130A was
evaluated alone '*1.13, 1.5 and 1.88 oz ailA and in combination with acetochlor, atrazine, and
metolachlor. Treatments of atrazine, metolaehlor, and atrazine in combination with acetochlor,
alachlor and metolachlor were included to represent commercial standards. Plots were 7.5 by
20 ft. and replicated three times in a randomized complete block design. 'Max 747' corn was
planted on May 114,1996. Treatments were applied on May 15, 1996 using a COz-backpack
sprayer that :E£eli 'ered 20 gpa at 22 psi. Control of yellow foxtail [Setaria lutescens (Weigel)
Hubb.], largec grass £Pieitaria saneuinalis (L.) Scop.], common lambquarters (ChenQPOdium
album L.), i t pigweed (Amaranthus retroflexus L.), and common ragweed (Ambrosia
artemisiifolia L.j were estimated on a scale of 0 to 100% (0 = no control and 100% = complete
control) 2, 4, 8,1and 15 weeks after treatment (WAT).
were determined]
I
Corn injury, silage and grain yields
All trea~ents provided excellent corn safety. EXP 31130A alone and in combination with
acetochlor, atrazine, and metolachlor controlled large crabgrass, common lambquarters and
redroot pigweed jeffectively up to 15 WAT. All treatments, with the exception of metolachlor
at 2.0 Ib aiJA, resulted in excellent common ragweed control. EXP 31130A at 1.13, 1.5 and
1.88 ozlA controlledyellow foxtail 60, 53, and 63% 4 WAT, while the same treatments gave
only 38, 40, an~ 55% control 8 WAT. In the second experiment, the same rates of EXP
31130A provide ~ similar degree of yellow foxtail control. EXP 31130A alone gave poor yellow
foxtail control (~5% or less) 15 WAT, whereas EXP 31130A when combined with any of the
acetamide treat1ents provided season long control.
Silage ~elds from EXP 31130A treatments ranged from 7.5 to 17 tonIA and were
significantly less than all other treatments (23 to 30 toniA) with the exception of metolachlor at
2.01b aiJA. G~n yields from EXP 31130A (38 to 100 bu/A) were also less than all other
treatments (151 tp200 bul A), with the exception of metolachlor at 2.0 lb ailA. Yield reductions
from EXP 3113f-A treatments were due to poor yellow foxtail control. Both grain and silage
yields of corn :resulting from EXP 31130A combination treatments were comparable to
commercials~ treatmentandbandcultivation.
'Professor and ~hnician, Departmentof Plantand SoilSciences,Universityof Massachusetts,
Amherst, MA 0 Visiting Scientist, Academy of Agriculture in Szczecin, Poland.
1003;
1
!
I
i
I
I
I
i
I
i
I
1