The growth of the young coconut palm (Cocos nucifera L.). I. The role of the seed and of photosynthesis in seedling growth up to 17 months of age

Abstract

The growth of coconut seedlings and the changes occurring within the seed were studied over a period of 17 months from the germination of the coconuts.

Removal of the husk prior to germination made possible an estimate of the endosperm content of each seed and also permitted the exact date of germination to be observed. Seedlings were grown with a non-limiting supply of water and nutrients; 63 seedlings were harvested on each of 10 occasions to enable a growth analysis to be made.

A high initial relative growth rate, arising through contributions by the endosperm, fell at 4 months to a level which remained roughly constant to 17 months. By 4 months the haustorium had reached its full size, but thereafter the relative contribution from the endosperm via the haustorium was much diminished.

Between 4 and 15 months a gradual change over to full dependence on photosynthesis took place. By 17 months less than 10% of the endosperm remained in the nut.

The rate of leaf production was constant with time, but the leaf area increased almost exponentially. There was some indication of a positive relationship between net assimilation rate and solar radiation. Some conclusions are drawn concerning cultural methods with young coconuts.