Ryegrass proving to be herbicide-resistant
ALEXANDRIA, La. (AP) — LSU AgCenter scientists say Italian ryegrass found in Louisiana has developed resistance to herbicide.
Daniel Stephenson said seed from fields in Tensas Parish was used to grow the plant and confirm its resistance to glyphosate.
Italian ryegrass is widespread in northeast Louisiana and has been found in St. Landry Parish to the southwest, Stephenson said.
The weed can rob a corn plant of 75 percent of its yield. It also poses a problem for cotton and soybeans because clumps of dead Italian ryegrass can interfere with planting and seedling growth.
A fall application of the alternative herbicide Dual Magnum is the best way to control it, Stephenson says, but the usual treatment of glyphosate and 2,4-D won’t kill it. Dual Magnum also suppresses the weed henbit, he said.