Relationships among rate and duration of flowering and seed yield components in subterranean clover (Trifolium subterraneum)

Abstract

Time of flowering, duration of flowering, rate of inflorescence production per unit area, viability of seeds harvested 20 and 30 days after anthesis, and seed yield and its components were measured on 24 subterranean clover strains grown as irrigated swards.

Seed yield was unrelated to time or duration of flowering, but positively correlated with rate of inflorescence production, total inflorescence, burr and seed numbers, number of seeds per burr, and seed size. Rate of inflorescence production was the main determinant of total inflorescence numbers per unit area and an important determinant of total burr and seed numbers per unit area. It was negatively related to flowering duration, and weakly so to seed size.

Seed size was unrelated to strain maturity. Seeds of small-seeded and fast-flowering strains on average attained viability faster than those of large-seeded and slow-flowering strains. Number of seeds per burr increased slightly with lateness of flowering, but was unrelated to seed size or flowering rate.

It is concluded that rapid flowering and high seed number per burr should be useful primary selection criteria in selecting subterranean clovers for seed yield and general adaptation in southern Australia.