TITLE:
Weed Control, Environmental Impact, and Net-Profit of Two-Pass Weed Management Strategies in Dicamba-Resistant Soybean (Glycine max) Using Conventional Tillage
AUTHORS:
Matthew G. Underwood, Nader Soltan, David C. Hooker, Darren E. Robinson, Joseph P. Vink, Clarence J. Swanton, Peter H. Sikkema
KEYWORDS:
Density, Environmental Impact, Injury, Profit Analysis, Tillage, Yield, Weed Control
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.8 No.13,
December
21,
2017
ABSTRACT: Traditional two-pass weed management strategies need
to be compared with new strategies in glyphosate/dicamba-resistant soybean.
Weed control, soybean yield, partial profitability and environmental impact
(EI) were evaluated in glyphosate/dicamba-resistant soybean using dicamba
applied alone or in a tank-mix with dimethenamid-P applied preemergence (PRE). Trials
were conducted at three locations during 2014 and 2015. Several PRE herbicides
provided excellent control of broadleaf and grass weeds. Dicamba provided > 91%
control of broadleaf weeds, and the addition of dimethenamid-P improved grass
control. All weed species at the trial locations were controlled > 94%
following a postemergence (POST) application of glyphosate. Weed interference
reduced soybean seed yield 33% where no herbicide was applied. A single POST
application of glyphosate had the lowest EI. Several treatments improved
early-season weed control and reduced early-season weed density and biomass
compared to glyphosate and had similar EI values. In this study, there was no
benefit to yield or partial profit by including a PRE herbicide for weed
management; however, the inclusion of multiple modes-of-action in a herbicide
program may reduce the selection for herbicide-resistant weeds.