Priming Effects on Field Germination and Initial Growth of Kentucky Bluegrass

摘要

Kentucky bluegrass (Poa pratensis L.) is a popular yet slowly establishing turf species. Not only does it require a long period of time to emerge from the soil, but bluegrass seedings have a low field survival percentage. In addition, erosion and environmental stresses make establishment of this species more difficult. The purpose of this study was to develop and refine the seed priming (osmoconditioning) of Kentucky bluegrass and to determine whether bluegrass germination and seedling growth could be improved under both laboratory and field conditions. The practical applications would include improvements in erosion control, seed production, and general turfgrass establishment. Solution concentration, duration of treatment, light requirement, and dry-back time were variables evaluated in this study. Seed tested, in all experiments, was "Baron" Kentucky bluegrass. Osmotic treatment solutions of NaCl and polyethylene glycol (PEG8000) were used to control moisture content, allowing the essential germination processes to occur up to the point of radicle emergence, but no further. A combination of low osmotic potential and long priming periods, light during priming and a short dry-back time enhanced the beneficial priming effect on Kentucky bluegrass. Germination index, a measure of germination rate, could be increased fourfold by priming the seeds before planting.