The use of annual ryegrass (Lolium multiflorum L.) as a winter cover crop by Midwest corn and soybean farmers has opened a market for Oregon ryegrass seed growers.

The advantage of annual ryegrass (ARG) over other cover crops is its ability to grow on poorly drained
soil under no-till farming systems (Hart et al., 2011). In addition, ARG is generally not hard to kill in the spring after it fulfills its function as a cover crop in the fall and winter, provided recommended management practices are followed (Plumer et al., 2016).

One of the main challenges of using ARG as a cover crop in the Midwest is selecting appropriate varieties that tolerate low temperatures (approximately 5–10°C;41–50°F) and produce good stand establishment in a cold environment. Although ARG is a cool-season grass, some varieties have better cold tolerance than others, depending on the genetic makeup of each variety.