Effect of Seeding Date, Seeding Rate, and Seed Treatments on Saltgrass Seed Germination and Establishment

Inland saltgrass [Distichlis spicata var. stricta (L.) Greene), native to the western United States, has potential for use as a turfgrass and a revegetation species on saline sites. This study was conducted (i) to evaluate the effect of seeding date, seeding rate, and seed treatments on saltgrass establishment; and (ii) to determine the required accumulative growing degree days (GDD) for saltgrass to establish adequate cover (>= 80%) after seeding. Seeding dates were 15 May, 15 June, and 15 July in 2006. Machine scarification and stratification broke saltgrass seed dormancy equally well. Saltgrass seeded in May established adequate coverage (>= 80%) in September even using the lowest seeding rate (74 kg ha(-1)). For plots seeded in June, only the higher seeding rates (123 and 170 kg ha(-1)) established adequate coverage (>= 80%) by the end of growing season. For plots seeded in July, however, even the highest seeding rate failed to establish adequate coverage in September. The accumulated GDD to achieve adequate coverage was 1748, 1663, and 1435 for 74, 123, and 172 kg ha(-1) seeding rates, respectively.