Date of Award


Degree Name

Master of Science


Plant and Soil Science

First Advisor

Gage, Karla


Shifts toward herbicide resistant weed populations in row crop agriculture is a widespread epidemic. Sequential applications of EPSPS synthase-inhibitors, acetolactate synthase-inhibitors, and other herbicide site-of-action groups, have led to the selection and spread of herbicide-resistant weed biotypes (Powles, 2008; Tranel and Wright, 2002). New soybean systems with resistance to auxin herbicides, along with proprietary herbicide formulations, have been developed to control these herbicide-resistant weeds in soybean production. These new technologies will be compared in both conventional- and no-till with technologies which have been available for several years, in the aspects of weed control, yield, and economic return on investment (EROI). In both 2016 and 2017, when using preemergence (PRE) followed by postemergence (POST) herbicide programs, there were few differences in weed control between the six soybean systems. Adequate grain yield was provided by all soybean systems when proper herbicide programs were used. EROI was the highest when optimum yields were achieved, regardless of treatment cost.




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