EFFECTS OF SEED PHOSPHORUS CONCENTRATION ON THE EMERGENCE AND GROWTH OF SUBTERRANEAN CLOVER (TRIFOLIUM-SUBTERRANEUM)

Subterranean clover seed (Trifolium subterraneum cv. Dalkeith) with ph osphorus concentrations of 0.75% (high P seed) and 0.48% (low P seed) and of uniform size (2.0-2.4 mm diameter) was used to measure the effe ct of seed P concentrations on seedling emergence and growth. Seedling emergence numbers were 35% greater for the high P seed, and this effe ct was independent of external P supply. High P seed also emerged more quickly than low P seed. Leaf emergence was faster and shoot dry weig ht was greater for seedlings grown from high compared with low P seed, but only when external P supply was deficient for plant growth. Phosp horus concentrations in the shoots of two-week old seedlings were 32-5 1% higher for high P seed, although by four weeks plants grown from hi gh and low P seed had similar concentrations of P in their shoots. We suggest that establishing pastures using high P seed would improve bot h early and late season pasture production.