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 30,000 acres in Roseau and Lake of the Woods Counties. In this region, perennial ryegrass is grown as a winter annual crop. Harsh 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 and economical benefits intrinsic to perennial agriculture. Using current commercial winter-hardy perennial ryegrass germplasm, we tested several alternative management strategies to boost second year yield.  Management treatments were applied first year post-harvest and were designed to reduce residue and thereby increase winter survival.  Residue management treatments included fall field burning, mechanical residue removal and an untreated control.  Additionally, following residue management, fall applications of four different plant growth regulators (PGR) and an untreated control were applied to the sward.  Plant growth regulators included ethephon, indole-3-butyric acid/kinetin mixture, mefluidide and prohexidione calcium.  The experimental design was a randomized block with four reps in a split plot treatment arrangement.  Three years of data were collected from on-farm research plots in Roseau County Minnesota during the 2014, 2015 and 2016 growing seasons.  Response variables included winter survival, spring greenup, mature plant height, lodging, seed yield, seed test weight, harvest index and volunteer seedling emergence.  Thus far, two trial years of data have been collected and analyzed.  In both years there was a significant effect of residue management on seed yield and winter survival.  Both residue management treatments consistently increased seed yield compared to the control.  There was no effect of PGR on either response variable.  Volunteer emergence was observed across treatments, which is a cause for concern with respect to seed purity and stand density.  Results of year three will be discussed.