EFFECT OF SEED MATURITY ON GROWTH AND QUALITY OF GREWIA OPTIVA DRUMMOND SEEDLINGS

摘要

Seed germination, growth and quality of Grewia optiva Drummond seedlings were studied in relation to stage of fruit harvest and diameter of mother trees. The seeds harvested on October 16 f rom medium sized trees (20-20 cm dbh) gave the best germination and subsequently the better quality seedlings. Normally, the seeds are collected after bulk of the crop 'ripe'. But date of maturation varies between trees within the same stand (Allen 1958) and between stands in the same year (Powells 1949). The seeds when harvested at optimum maturity gives greater vigour and, therefore, potential for establishment of new seedlings (Pollock and Roos 1972). Immature seeds are usually incapable of germination (Ching 1960 and Rediske and Nicholson, 1965) and even when germinate, are slow (Shearer 1977) and produce high proportion of abnormal seedlings (Krugman 1966).