Salinity and Trinexapac-Ethyl Effects on Seed Reserve Utilization and Seedling Growth of Two Lolium perenne Cultivars

Plant growth regulators are frequently applied for warm-season turf just before over-seeding to increase the turf performance, and its competitive ability. In situation that the turfs are irrigated with saline water, the time of TE application on turf is critical. Seeds of two perennial ryegrass cultivars were adjusted to different salinity levels (0, 2000, 4000 and 6000 mg.L-1 NaCl) and TE (0, 50 and 100 g . ha(-1)) levels which individually performed in agar and soil to detect their effects on germination and initial growth. Seed germination percentage, germination rate, weight of mobilized seed reserve and seed reserve depletion percentage were significantly affected by TE, and salinity with an exception of seed reserve utilization efficiency in the first experiment. TE inhibited germination percentage more severely in higher concentration. The results showed that TE had no significant effect on chlorophyll concentration, height, electrolyte leakage, root length, the fresh and dry weight of seedling, but salinity significantly decreased all of them. It postulated that TE application before over-seeding had deleterious effects on over-seeded grass germination; however, because it had no effects on initial growth of turf, it can be used in this stage.