Influence of Different Pre-Sowing Treatments on Seed Dormancy Breakdown, Germination and Vigour of Red Clover and Italian Ryegrass

A two-year study was conducted using seed of six cultivars of Trifolium pratense (red clover) and three cultivars of Lolium multiflorum (Italian iyegrass), to test the effect of different treatments including exposure to 50% H2SO4 for 10, 30, 60, 90 min; to 80 degrees C temperature for 10, 30, 60, 90 min; gibberellic acid (GA(3)) at 250, 500, 1000 and 1500 mg L-1; and potassium nitrate (KNO3) at 0.1, 0.2, 0.35 and 0.5%. Germination, dormancy and vigour of both red clover and ryegrass were assessed. In case of T. pratense seed, there was a significant (p <= 0.05 or p <= 0.01) interaction between all the cultivars and treatments. A significant (p <= 0.05) interaction was also observed between the L. multiflorum cultivars and H2SO4 including temperature treatments. However, no significant interactions were noted between the GA(3) or KNO3 treatment, germination and vigour. The results showed that by selecting the optimal treatment (H2SO4 30' or H2SO4 60'T. pretense and GA(3) 1000 mg L-1 L. multiflorum) for a particular cultivar it is possible to significantly improve germination and vigour, and thus ensure technologically more effective and economical establishment of a grass-legume mixture of L. multiflorum and T. pratense. (C) 2018 Friends Science Publishers