Resistant Italian Ryegrass Cropping Up in Winter Whea

As if dealing with resistant Palmer pigweed in the summer isn’t challenging enough, Dr. Wes Everman, NC State Extension Week Specialist says there’s now a resistant winter weed; Italian winter ryegrass:

“We are facing a broad problem with resistance across the state with every class of post emergence herbicide available. Our ACCA inhibitors as well as our ALS inhibitors.”

Everman says there are a couple of herbicides that have proven effective, but if only used in the right situation and conditions:

“Right now we are really relying on pre-emergence products or spike stage. For Pre-emergence we have valor or a new product that has valor and pyroxasulfone in it that can be applied up to 7 days before planting in a no till. We got good suppression of the rye grass but on light soils where we haven’t had rainfall before planting, we can see injury on the wheat. We have to be careful having the right soil type.”

There are products that can be applied post-emergence, says Everman, but again, the conditions have to be just so:

“Products for the spike stage can be applied once the wheat has emerged. But the problem is we don’t control any of the emerged rye grass.”

So, here we are at the end of January, winter wheat has been emerged for some weeks now. Everman has this recommendation for resistant ryegrass in taller wheat:

“Unfortunately we do not have options, if you have multiple resistance, we just have to hope the crop is competitive and can still make the yield. If there is a high population of ryegrass it might be best to cut that part for hay.”