Author : Ilagan, Millicent C.

Summary : An evaluation for the general adaptability of nine coconut genotypes commonly grown in three research stations of the Philippine Coconut Authority was conducted to determine the environmental factors that greatly influence the yield and range of adaptability of the coconut genotypes and to identify the widely adaptable coconut hybrids/cultivars from among the nine genotypes. Variuos statistical procedures were used, namely: simple correlation analysis, step-wise regression technique, and the beta response methodology which used the principal component analysis. Four environmental variables, namely: annual amount of rainfall, minimum temperature, percent silt, and percent clay were identified as the most important factors affecting yield variation and the range of adaptability of coconut. These variables were used in the deriving an environmental index which was in turn used in the identification of widely adaptable genotypes by the beta response method. The adaptability ranking of the different coconut genotypes revealed that the hybrids were more adaptable to varying environments than the local cultivars. In particular, two foreign hybrids, Yellow Malayan Dwarf x West African Tall (YMD x WAT) and the Equatorial Green Dwarf (GDE) x WAT ranked as the most adaptable genotypes. This confirmed the earlier claim of coconut scientists that these hybrids are suited to a wider range of environments. At the same time, our local hybrid, Catigan x Bagoshiro (CAT x BAO) showed promising potential which was comparable to the foreign ones. The higher general adaptability of the hybrids could be due not only to their physiological homeostasis and phenotypic plasticity but also to the heterogeneity and heterozygosity of their gene constitution. Based on the findings of this study, the choice of YMD x WAT and other foreign hybrids as planting materials for the initial implementation of the coconut replanting program proved to be justifiable. Likewise, CAT x BAO hybrid is worth considering for recommendation to our coconut farmers. Results also indicated that more coconut genotypes must be evaluated for their general adaptability considering the wide genetic variability of this crop. Furthermore, the need to identify promising genotypes for recommendation to coconut farmers should be given high priority by our government.