Spring wheat canopy effects on light dynamics and yield of intercropped fine fescues

Turfgrass stakeholder surveys have indicated fine fescue (Festuca spp.) seed will become in higher demand, but fine fescue seed production in the United States, especially in Oregon, has not increased. Northern Minnesota is conducive for cool-season turfgrass seed production and has existing infrastructure to produce turfgrass seed. There is an exciting opportunity for Northern Minnesotan farmers to increase revenue by producing fine fescue seed; however, fine fescues require a growing season for establishment prior to seed production, and an economic crop during the first growing season is needed. Most fine fescues are considered shade tolerant and should establish under spring wheat (Triticum aestivum L.), which is the current cropping system used for perennial ryegrass (Lolium perenne L.) seed production in Minnesota. Experiments were established in Roseau (2018 and 2019) and St. Paul (2018) in which several cultivars of Chewings, hard and strong creeping red fescue were interseeded with spring wheat. Our objectives were to examine stand and seed production of these three fine fescue taxa in comparison with perennial ryegrass. All three taxa were negatively affected by wheat, possibly from excessive shade from the wheat canopy. The fine fescue culm index (number of culms relative to whole-plant biomass) grown in wheat was lower, indicating that vernalization was negatively impacted, resulting in seed yield reduction. Our results demonstrate that the currently used perennial ryegrass–spring wheat cropping system is not optimized for fine fescue seed production, especially hard fescue, and more research is needed to improve this cropping system in Northern Minnesota.