Degree Name

Master of Science

Department or Program

Agribusiness Economics


Sanders, Dwight R.


With the widespread epidemic of herbicide resistance in weeds, and relatively low cash market prices, the economic sustainability of weed management programs in soybeans is of critical importance. Growers in Southern Illinois and across the Midwest face a wide variety of competitive weeds, with some populations expressing resistance to multiple herbicides, which can make it difficult and costly to select an effective herbicide program. Over-reliance on broad-spectrum herbicides such as glyphosate has helped to create this shift in herbicide resistant weeds. Utilizing data collected in southern Illinois during the 2016 and 2017 growing seasons by Matt Geiger, we will test the economic sustainability of various herbicide programs common in Southern Illinois. A regression model was used to assign yield benefits or reductions to six different soybean systems and their respective herbicide programs. Economic return on investment was greatest when using preemergence (PRE) followed by postemergence (POST) herbicide programs across all soybean systems. Treatment costs were comparable for all soybean systems, implying that weed control and yield was most important.