Authors: Travis Legleiter, Bill Johnson, Bryan Young; Purdue University Extension
Annual ryegrass has become a popular cover crop in many Midwest states. It can be a favorable cover crop as it establishes quickly, is able to survive winters and have high biomass potential. It is also valued as it is able to sequester and release nitrogen. All that said, it is also considered a weed. And has become a major pest in the South. It can be tough to control and has shown resistance to several sites of action including ACCase inhibitors, ALS inhibitors, glyphosate and glufosinate.
Purdue University extension recommends in the Purdue Weed Science paper "Successful Annual Ryegrass Termination with Herbicides," that only experienced cover crop growers grow annual ryegrass. And they give tips on proper herbicides, application timing and
Rates to help successfully terminate a ryegrass crop. Through their research trials, annual ryegrass termination has typically occurred between April 15 and May 1.