Influence of genotype, seed size, and seedling density on the winter herbage production of subterranean clover (Trifolium subterraneum L.) lines and cultivars

摘要

Abstract An important factor often limiting stocking rates in cool-temperate environments is winter growth. Field trials were carried out to test the hypothesis that if the effect of seedling density and seed size is accounted for, then significant differences in winter production between cultivars and lines of subterranean clover can be detected. Winter production of second-year swards was measured on 11 lines of Trifolium subterraneum variety subterraneum and four crossbreds variety yanninicum from the National Subterranean Clover Improvement Programme (NSCIP), together with 15 commercial cultivars. Three sites were sown in autumn 1987 at Cressy (Midlands), Bridport (North East Coast), and Swansea (East Coast) in Tasmania. On average, the most productive line in winter was CPI 89820D, with a clover dry matter (DM) production of 964 kg/ha. The commercial cultivars Karridale and Enfield averaged 876 and 818 kg DM/ ha. Seedling density accounted for 45, 69, and 73% of the variation in winter production at ...