Don’t forget to control your annual ryegrass this spring
Consider weather and proper tillage for effective annual ryegrass control.
Annual ryegrass (Lolium multiflorum) has become a popular cover crop in Michigan and the Upper Midwest. Annual ryegrass is often mistaken for cereal rye. Annual ryegrass is a grass seed while cereal rye is a grain more similar to wheat. Annual ryegrass is a very competitive winter annual. It is a bunch grass that should be killed and controlled in the spring. When using herbicides, the best results have been achieved when used before annual ryegrass reaches the joint stage. Most studies suggest killing annual ryegrass between 6 to 9 inches.
Weather can play a role in effective annual ryegrass control. When using a translocating herbicide such as glyphosate, warm conditions will enhance control. Daytime temperatures should be in the 50s or 60s and night time temperatures in the 40s. One night in the 30s will not drastically reduce performance. Cloudy and wet conditions will slow glyphosate activity. If annual ryegrass greens up, an additional application may be necessary.
Cool weather can affect glyphosate applications. Under cool temperatures – 30°F to 40°F nighttime temperatures – allow the dew to dry before applying glyphosate; under these conditions you may need to apply a second burndown application.
Tillage is also an effective control of annual ryegrass. It is still recommended that you control annual ryegrass with tillage early when it is between 6 to 9 inches tall. Farmers should wait about two weeks before planting a new crop after killing annual ryegrass with tillage.