Central Plantation Crops Research Institute, Kasaragod 671 124
The influence of carbohydrate fractions and nitrogen content in leaf, subtending inflorescence on female flower production and shedding was investigated in coconut. Twelve-year-old coconut palms of D × T combinations, i.e. Chowghat Orange Dwarf × West Coast Tall (COD × WCT), Malayan Yellow Dwarf (MYD) × WCT and Malayan Orange Dwarf (MOD) × WCT growing under non-irrigated conditions were used.
The observations were taken during rainy (June–August) as well as summer seasons (January-March). Significant reduction in carbohydrate fractions in leaf as well as female flower production was observed two months after opening of the inflorescence compared to initial stage. However, significant correlation was not observed between the parameters two months after opening of inflorescence and shedding of buttons. Seasonal changes were also significant for the parameters studied. During rainy season, a negative correlation between shedding of buttons and carbohydrate fractions as well as C:N ratio was observed. Whereas in summer season, only C:N ratio showed negative correlation with shedding of buttons. During both the seasons, shedding was highly correlated with number of female flowers production. Thus, coconut regulate the female flower production and shedding of buttons through the operation of a steady carbon-nitrogen metabolism which in turn is regulated by the environmental variables. However, genetical control on flower production and shedding of buttons cannot be ruled out.
