Shedding of buttons in coconut (Cocos nucifera): role of carbohydrate fractions and nitrogen content in leaf subtending the inflorescence

摘要

Flowering in coconut is a continuous process, and development and growth of inflorescence have been found to be intimately associated with the development and growth of the leaf (Patel, 10). Once the inflorescence (spadix) opens, it takes about 12 months for full maturity of buttons and harvesting of nuts. In coconut, fertilized flowers, up to 4 months of maturity are usually designated as buttons. Being a tree crop of identerminate growth habit, the partitioning of metabolites towards vegetative and reproductive growth is a continuous process and inter linked during the entire span of its life. Production of a large number of female flowers, good fruit setting and retention of nuts have an important role in improving the production potential of palms and shedding of buttons is the major setback in coconut production. Ramadasan and Mathew and Kasturi Bai and Ramadasan have reported the role of carbohydrate fractions in flowering of coconut, They observed that high carbohydrate reserve in the trunk as well as high carbohydrate: nitrogen ratio (C/N) are prerequisites for commencement of flowering. Kasturi Bai and Ramadasan (5) observed high relationship between soluble carbohydrate fractions and commencement of first flowering in juvenile palms. However, reports are not available on the role of carbohydrate fractions as well as nitrogen content in subtending leaf for the development of inflorescence growing in its axil. Therefore, carbohydrate fractions and nitrogen content in the leaf subtendinginflorescence at the time of opening of inflorescence and two months after opening as well as seasonal changes in carbohydrate fractions and nitrogen content in subtending leaf, in relation to female flower production and shedding of developing fruits were investigated.