EFFECTS OF SEED SIZE AND EMERGENCE TIME ON SUBSEQUENT GROWTH OF PERENNIAL RYEGRASS

Abstract

SUMMARYThe seed weight of individual perennial ryegrass seeds was measured prior to recording their date of emergence and subsequent growth in experimental populations raised in the glasshouse and sown at different initial densities. Seed size did not correlate with time to emergence although lighter individuals had a slightly lower probability of emergence. Seed size had no statistically significant effect on subsequent tillering up to 27 weeks, or on the dry wt attained by this time.The time from sowing to emergence was significantly related to subsequent tillering of the grass plants for a number of weeks in populations sown at different densities. After some 20 weeks the effect of emergence time became non‐significant. This coincided with the onset of tiller mortality in the population. Even after 27 weeks individual emergence time was inversely related to dry wt but was not related to mean tiller weight.