This project will quantify the weed control and economic benefit of using a layered residual herbicide with narrow row spacing in two weed management systems. Trials will be conducted 3 locations in central and eastern Kansas.

a. Compare weed control and soybean yield in 30- and 15-inch row spacing
b. Compare weed control and soybean yield with and without over-the-top residual herbicide
c. Evaluate the interaction of row spacing and overlapping residual herbicide use

Update:
Trials were successfully established at all three locations. Preliminary results were shared with farmers at the Ottawa and Scandia field days. The project has been submitted for presentation at the North Central Weed Science Society annual meeting in December.

View uploaded report

Update:
Project results have been presented at field days in Ottawa and Scandia, KS. The graduate student managing the project is currently preparing his thesis and the manuscript for publication in a peer-reviewed journal.

Including Dual Magnum in the postemergence herbicide application did not result in a statistically significant increase in visual estimates of weed control at any location, even when there were differences in soybean populations. However, it is important to remember that a small difference in estimated control of weeds like waterhemp and Palmer amaranth can result in greater weed populations in future years. Furthermore, weed escapes increase the likelihood of herbicide resistance, especially in weeds with a lot of genetic diversity, like waterhemp and Palmer amaranth. Results of partial budget analyses varied with location, with few discernable trends.