Persistence of seed produced from single seed crops of subterranean clover on sandy soils near Esperance, Western Australia

Abstract

The number and weight of seeds per unit area, and weight per seed were measured for single seed crops of 6 subterranean clover cultivars grown as dense single strain swards on sandy soil near Esperance, W.A. In the sowing year, weight and number of seeds and weight per seed varied with cultivar and year of sowing. In the regeneration years, weight of seed decreased by about 60% between the first and the second year (range 50-75%, depending on cultivar and year of sowing), by a further 27% between years 2 and 3 (range 20-3g%), and a further 3.2% between years 3 and 4 (range 1.7-5.0%). The relative decrease in numbers of seed per unit area, to year 4, followed almost identical trends. Individual seed weight was constant for each cultivar sown in the same year, with the exception of 1 experiment sown in 1982 when seed collected in the next 2 regeneration years was 1.1-1.4 times as heavy as seed produced in the sowing year. In the sowing year, seed collected about 1 week after the clover had dried off contained less than 4% moisture (dry weight basis) and most of the seed were impermeable (hardseeded).