How many of you had an issue with glyphosate-resistant Italian ryegrass this spring? Did you expect clethodim to solve the problem and then found it did not? Did you apply paraquat and were not satisfied? Many farmers, consultants, and dealers commented to me since late January that the Italian ryegrass problem has exploded in Louisiana. Honestly, this is not surprising because we have not been addressing this pest properly. Mississippi has had this issue for longer than Louisiana has. Mississippi State University weed scientists determined a good strategy to manage glyphosate-resistant Italian ryegrass five or six years ago. LSU AgCenter weed scientists adopted their strategies and began disseminating that plan. It starts with tillage or a residual herbicide application in the fall, which has not been adopted by many producers in Louisiana. This article will not go into detail about Mississippi State University’s glyphosate-resistant Italian ryegrass management plan in this article, BUT it will be covered at length later this year.
I am writing this article because I would like for Louisiana farmers, consultants, dealers, and ag lenders to notice that glyphosate-resistant Italian ryegrass is still present in corn, cotton, and soybean fields on May 1st. It may be brown following herbicide applications, but it is still competing with crops as you can see in the photo (Figure 1).
Do not take glyphosate-resistant Italian ryegrass lightly. Remember what crop fields look like in the spring so that you will be motivated to implement good management strategies in the future. More to come later. If you have questions, please contact your LSU AgCenter parish agent. Feel free to contact me at 318-308-7225. Have a great day.