Date of Award


Honors Thesis Number



Plant and Soil Science

Faculty Advisor

Kapusta, George A.


Accent and Beacon, both recently labeled postemergent corn herbicides, were applied at ' simulated' drift rates to soybeans at the V3 and R1 development stages. Drift rates were simulated by applying 10 to 50% of the respective labeled rate for each herbicide. Injury was more evident at the V3 stage than at the R1 stage for both herbicides. Injury caused by Beacon was significantly greater than with Accent for both applications, and appears to be a considerable threat for high-risk drift situations when applied near soybeans. Each herbicide exhibited specific, characteristic symptoms of injury that clearly coincided with increases in rate. Yields ranged from 30 to 53 bushels per acre; however, they did not exhibit the extent or variation of damage that was evident in the early injury levels. This was due to considerable recovery of the soybeans toward the end of the season, especially with the Beacon treatments that had initially sustained the most injury.