August 2024 Edition

Agriculture & Natural Resources
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Farmers in Simpson County and many grain producing counties in Western Kentucky have struggled with the control of Italian Ryegrass.  Italian Ryegrass has been confirmed to have glyphosate resistance in Simpson County and has shown signs of resistance to other chemistries.  In order to help producers combat this issue, the Simpson County Extension Service and UK Extension Weed Specialists looked at control options for Italian Ryegrass in winter wheat during the 2023-2024 growing season.  Identical trials took place on a farm in Northeastern Simpson County with a recent history of ryegrass issues as well as at the Princeton Research and Education Center (UKREC). 

Situations that were encountered with on-farm research is that the densities of ryegrass in the field was inconsistent across the plot area which is typical.  This likely resulted in not seeing statistical differences between treatments in Simpson County, but we think the numerical values can still be of benefit to producers, especially when comparing them to what was found at the UKREC.

After analyzing the data, we concluded the following.  Anthem Flex performed the best and was equivalent whether we put it all on at planting or split it.  Fierce EZ needed to all go out prior to planting to maximize control.  The split Fierce EZ did not hold up, likely due to the limitations of the labeling for rates.  If Fierce is split you must have metribuzin in the POST application.  Based on trial results, it appears that Axial Bold had little effect on the ryegrass in Simpson County at this location.

This is only one year of data, so it is a small sample size in that regard.  We plan to continue this research to help strengthen and expand upon the results that were observed during these trials.  We want to share this data to help producers in making herbicide decisions on winter  wheat this growing season.  If you would like to see more details about dates, rates and control, feel free to reach out the Simpson County Extension Service by calling (270) 586-4484.