Seed Production in Radiata Pine Seed Orchards in Australia

Abstract

SUMMARY Seed production records of six radiata pine orchards in south eastern Australia are presented and examined. Yields commence at about age 5 years and increase to about 20 kg/ha at age 10–12 years, though crops vary and some are much heavier. There is evidence that yields will continue to rise as the orchards become older, but it is likely that difficulties of harvesting from large trees will limit rotations to about 20 years. Differences in yield between orchards are notable, and appear to be due primarily to locality effects. Factors affecting yield include environmental influences (moisture, nutrition and temperature), genetic variation, and cultural treatments (spacing, thinning, pruning and type of vegetative propagule).