Comparison of Fall Residual Herbicides Targeting Italian Ryegrass

Glyphosate-resistant (GR) Italian ryegrass (Lolium perenne ssp. multiflorium) was first documented in field crops in Washington County, Mississippi, in 2005.  Thirteen counties in Mississippi now contain populations of GR Italian ryegrass.  Fields with GR Italian ryegrass not controlled at burndown will have significant plant residue at planting.  Residue will impede planting practices, contribute to competition between crop seedlings and established GR Italian ryegrass, and hinder herbicide programs due to inadequate coverage.  Research at the Delta Research and Extension Center in Stoneville, MS, has demonstrated that residual herbicides applied in the fall offer the best opportunity for controlling GR Italian ryegrass.