Managing Glyphosate-Resistant Italian Ryegrass

By Jim Steadman|October 14, 2016

Problems with glyphosate-resistant (GR) Italian ryegrass escalated during 2016 in Mississippi. In fact, Jason Bond, Mississippi State Extension weed scientist, declared this year the worst to date for this weed.

“The reasons why can be debated,” says Bond. “But the fact is GR Italian ryegrass has spread at an alarming rate across Mississippi, especially considering Italian ryegrass seed are not spread by wind.”

In an MSCrops blog post, Bond notes that weather across the Mississippi Delta over the past 5 to 6 weeks has allowed for extensive field preparations for 2017 behind corn, soybean, rice, and cotton in some cases. The lack of rainfall during September and early October also prevented excessive weed germination following harvest.

The best chance, says Bond, for reliable GR Italian ryegrass control is with residual herbicides applied in the fall. In his post, Bond offers several management suggestions for 2016-17.