Degree Type

Creative Component

Semester of Graduation

Spring 2020



First Major Professor

Dr. Robert Hartzler


Master of Science (MS)




With the development of 2,4-D in the 1940s, farmers were able to selectively kill broadleaves in corn (Zea mays). 2,4-D was an effective and powerful tool that allowed farmers to reduce the time spent cultivating cornfields. The development of herbicides allowed farms to increase in size due to the reduction in the time spent interrow-cultivating. Monsanto’s introduction of glyphosate-resistant (Roundup Ready) soybean (Glycine max) in 1996 continued the expansion of farm size. Glyphosate-resistant crops allowed farmers to adopt a “spray and forget” weed management program that was widely adopted. The simplified weed management programs were successful until glyphosate-resistant weeds evolved.

Although glyphosate was not the first herbicide that weeds developed herbicide resistance, the loss of glyphosate effectiveness created a sense of urgency for farmers. Farmers began to rethink their herbicide management to stay ahead of the challenges herbicide-resistant weed populations create. To combat resistant weed populations, farmers and professionals typically include additional herbicides in their weed management programs. This increases the likelihood of herbicide incompatibility, antagonism, and crop damage. A comprehensive understanding of herbicide mode of actions, site of actions, and potential crop damage is needed to make proper chemical recommendations and reduce the likelihood of crop damage.

Copyright Owner

Friedrich, Justin

File Format

Word, PP