Vol. 54—2000 - NorthEastern Weed Science Society

COMPARING 1MAZAPYR, lMAZETHAPYR, PENDlMETHALIN AND HALOSULFURON­
METHYL FOR CONTROLLING WEEDS IN 1M! CORN
D. M. Goodale l
ABSTRACT
Geneticallymanipulatedcom acresplantedannuallyarecontinuingto rise. In turn,this
expandsthegrowers'weedcontroloptionsbothin availableherbicidesandthe time of
applications.Thepurposeof thisstudywasto comparea traditionaltreatmentof pendimethalin
and halosulfuron-methyl to imazethapyr alone and premixed with imazapyr (Lightning). The
null hypothesisindicatedno significantdifferencein weed controlor yield betweenthe selected
herbicides.
The study was established as a randomized complete block design with 4 replications.
Mycogen 2285 was planted the second week in May into a 58 degree F soil and a planting of
34,000 seed per acre. A commercial field sprayer fitted with 8004 nozzles adjusted to 38 psi was
used to apply all treatments two days after planting except for the halosulfuron-methyl which
was applied10dayspost emergenceusingthe samesprayer.Theselected herbicideswere
applied at the labeled rates including imazetbapyr at 1.44 ozlA, premixed imazethapyr plus
imazapyr at 1.28 ozlA, and pendimethalin at 3.6 ptsJA and halosulfuron-methyl at 1.3 ozlA.
The resultsof the studyshowedno significantdifferencein weed controlor silage yield
betweenthetreatmentshencethe null hypothesiswas accepted. Basedon the resultsof the
study, a grower might well select from the threetreatments based on the cost of the products
and/orthe aestheticappearanceof the field. Imazethapyror imazethapyrplus imazapyr provided
comparatively less expensive yet observably betterweed control than the traditional
pendimethalin followed by halosulfuron-methyl applied early post.
1 Dean, Division of Agriculture and Natural Resources, SUNY Cobleskill, Cobleskill, NY
12043
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