Post‐Harvest Residue Management of Creeping Red and Chewings Fescue Seed Crops

Legislative actions in the Pacific Northwest have greatly restricted the total area of grass seed crops that can be burned each year. Grass seed growers are searching for alternatives to postharvest residue burning. In on‐farm experiments in western Oregon, we compared four postharvest residue management methods for effects on seed yield of creeping red fescue (Festuca rubra L. subsp. rubra cv. Cindy) and Chewings fescue (Festuca rubra L. subsp. commutata Gaudin cv. Center). Treatments were (i) straw residue removed and stubble flail‐chopped (flail‐chop), (ii) straw residue removed and stubble close‐clipped and vacuum‐swept (close‐clip), (iii) straw residue removed and stubble propane‐burned (propane‐burn), and (iv) residue and stubble open‐burned with full straw load (open‐burn). Seed yield components were also measured, to identify the component through which treatments affected yield. Treatment effects on seed yield of both crops interacted with years. Averaged across years, creeping red fescue seed yield was 993, 903, 804, and 620 kg ha−1 for open‐burn, propane‐burn, close‐clip, and flail‐chop treatments, respectively. The greatest treatment effect was on number of panicles, and consequently on number of floret sites and seeds produced per unit area. The number of spikelets per panicle, florets per spikelet, and seeds produced per panicle were unaffected. Open‐burn also resulted in the fewest weed seeds and the highest purity of the harvested seed. Treatments affected Chewings fescue seed yield in only one year, when seed yield was 750, 680, 477, and 553 kg ha−1 for open‐burn, propaneburn, close‐clip, and flail‐chop treatments, respectively. Treatments did not affect the number of panicles or seeds produced per unit area in Chewings fescue, the number of weed seeds, or the purity of the harvested seed. We concluded that mechanical removal of postharvest residue in Chewings fescue can maintain seed yield and seed quality similar to open‐burn. In contrast, open‐burn is required to achieve maximum seed yield and seed quality in creeping red fescue.