Exploring alternative management options for multiyear perennial ryegrass seed production in Northern Minnesota

Perennial ryegrass (Lolium perenne L.) is grown as a biennial when produced for seed in Minnesota; however, producers desire multiyear seed production. One approach to achieving multiyear seed production could be through improved management practices. In particular, plant growth regulators (PGRs) and fall residue management could help overcome several obstacles hindering multiyear seed production in northern climates. We assessed the impact of fall residue management practices and various PGRs after first-year harvest on winter survival and second-year seed yield of perennial ryegrass grown in northern Minnesota. The experiment was conducted for three trial years from 2013 to 2016 in second-year perennial ryegrass seed production swards. Three fall residue management treatments and five fall-applied PGR treatments were evaluated in a split-plot design. Fall-applied PGRs had no effect on second- year seed yield and minimal effects on winter survival. Managing residue by open-burning consistently resulted in significantly higher second-year seed yields than in the no residue removal control (1064 vs. 680 kg ha^-1, respectively). Open-burning and baling and mowing residue resulted in similar seed yields in 2 out of 3 yr, and both increased yields compared with no residue removal. Winter survival was only moderately affected by residue management, was highly dependent on year, and had an impact on mean seed yields across treatments. This indicates that winter survival and fall residue management are both important in maintaining multiyear seed yield in Minnesota.