Exploring the Possibility of Multi-Year Perennial Ryegrass Seed Production in Minnesota.

Perennial ryegrass (Lolium perenne) seed production is an important component of the agricultural economy in northern Minnesota, encompassing over 40,000 acres in Roseau and Lake of the Woods Counties. In this region, perennial ryegrass is grown as a winter annual crop. Severe winter conditions are typically the precursor to severe yield reductions going from the first to the second year of seed production making multi-year seed production unprofitable. Consequently, this system does not achieve the environmental benefits intrinsic to perennial agriculture. Using current winter hardy perennial ryegrass germplasm, we tested several alternative management strategies to boost second year yield.  Management treatments were applied post first year harvest and were designed to reduce residue and increase winter survival.  Residue management treatments included fall field burning and mechanical residue removal and were tested with fall applications of five different plant growth regulators (PGR) in a split plot design.  Plant growth regulators included ethephon, indole-3-butyric acid/kinetin mixture, mefluidide and prohexidione calcium.  Two years of data were collected from on-farm research plots in Roseau County during the 2014 and 2015 growing seasons.  Response variables included winter survival, seed yield, seed test weight, height, lodging, harvest index and volunteer seedling emergence.  In year 1, there was a significant effect of residue management for both winter survival and seed yield at both locations with a significant effect of location. No significant effects were observed with any PGR treatment. Results suggest that fall field burning and mechanical residue removal would both increase the success of a second year perennial ryegrass seed crop.