Vol. 51—1997 - NorthEastern Weed Science Society

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EFFECT$ OF EXP 31130A AND FOE S043ON WEED CONTROL AND
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CORN YIELD
I S. Kushwaha and P. C. Bhowmik 1
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ABSTRACT
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Three fiei-' experiments were conducted at the Agronomy Research Farm, South
Deerfield to stud the effects of EXP 31130A and FOE 5043 on weed control and com (Z&a
manL.) in 199 .. EXP 31130A at 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 oz ailA and FOE 5034
0.25, 0.5, 0.75, ~.O, 1.25 and 1.5 Ib/A were examined separately in randomized complete
block design. TIle split plot design hadtwo growth stages of herbicide application (pRE and
POST at the 1- ~ 2-leaf stage of com) as mainplots, and treatment combinations of EXP
31130A at 1.0, Il 5 and 2.0 ozlA and FOE 5043 at 8, 12 and 16 ozlA and a premix
combination of a . e + metolachlor at 2.5 Ib/A as sub-plots. Treatments were replicated
three times in all experiments. Weed counts were taken 3, 6 and 9 weeks after treatment
(WAT) and w dry weights were determined 3, 6,9, and 12 WAT. Weed control was
estimated on a e of 0 to 100, where O=no control and 100=100% control, at 8, 9, 12,
and 15 WAT. S age and grain yields of com were determined.
EXPa::;~.at 0.5, 1.0, 1.5, 2.0, 2.5 and3.0 ozIA controlled largecrabgrass
[Di&itaria i' (L.) Scop.] and common lambsquarter (ChenQPOdiumlUminL.) over
95%. ThiS~ was i flected by the reduction of weed number and weed dry weights. The 3.0
ozlA rate of 31130A controlled yellow foxtail [Setaria lutescens (Weigel) Hubb.] only
over 70% 8 WA with reduced control later in the season. None of the EXP 31130A
treatments resuI~ in silage or grain yields comparable to that of the cultivated check (23.3
ton/A and 143.3/oulA).
In secondiexperiment,FOE 5034 at 0.5, 0.75, 1.0, 1.25 and 1.5 Ib/A gave over 95%
control of yello~ foxtail and large crabgrass. FOE 5043 at 0.75 to 1.5 Ib/A controlled
common lambsquarterover 85% throughout the entire season. All FOE 5043 treatments
except the 0.25 leI A resulted in com silage and grain yields comparable to that of the
cultivated check 126.7 ton/A and 167 bu/A).
In third experiment, all treatment combinations of EXP 31130A and FOE 5043,
regardless of theE'timing of application, resulted in over 95 % control of large crabgrass and
common lambsq r. All treatment combinations whether applied PRE or at the 1- to 2­
leaf stage contro l ed yellow foxtail over 80%. However, yellow foxtail control was reduced
later in the season.Atrazine + metolachlor combination treatment gave better yellow foxtail
control when applied at the 1- to 2-leaf stage compared to the PRE application. Regardless
of the timing of ~pplication, all treatment combinations resulted in com silage and grain
yields comparabi to that of the cultivated check (27.6 ton/A and 182.1 bu/A).
IGraduate ResecufchAssistant and Professor, Department of Plant and Soil Sciences,
University of Massachusetts, Amherst, MA 01003
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