The growth of the young coconut palm (Cocos nucifera L). II. The influence of nut size on seedling growth in three cultivars

Abstract

The growth of three coconut cultivars of the tall type from germination up to 17 months of age was compared by growth analysis. These cultivars differ considerably in mean nut size. Within each cultivar a comparison was also made between the growth of seedlings from small, medium, and large nuts. There were considerable differences between cultivars in seedling growth up to 2 months but these differences did not persist. Similarly differences due to nut size within cultivars were recorded at early harvests but had disappeared by 6 months. Thus neither genotype nor nut size had any sustained effect on the plant size. Consumption of endosperm depended on seed size: evidently a lower, compensating net assimilation rate occurred in plants with large nuts to give a similar total supply of assimilate. This suggests that the potential supply of assimilate was not limiting the growth rate. Large nuts transfer dry matter from the endosperm more rapidly than do smaller nuts; hence under unfavourable conditions for photosynthesis, larger nuts may produce larger seedlings. It is suggested that any seedling selection should be done in a favourable nursery environment so that emphasis is placed on differences in seedling vigour due to genetic variation.