Studies on fruit set in coconut upon artificial pollination in various cross combinations

Abstract

Studies on fruit set in coconut have important implications in nut yield. A detailed study was carried out to determine the fruit set in coconut as influenced by variety, cross combination, climatic variables such as rainfall, temperature and relative humidity. Artificial pollination was carried out on selected parental palms of West Coast Tall (WCT), Chowghat Green Dwarf (CGD) and Chowghat Orange Dwarf (COD) in farmer’s plots over a period of five years commencing from 1996-2000. The various cross combinations tried among the three varieties, viz., WCT, CGD and COD were three selfing, two inter se and three crosses. The mean fruit set for the different cross combinations was 24.67%. The maximum fruit set (39.54%) was in COD (self) followed by WCT (self) and COD x WCT, and minimum in CGD x WCT (19.16%) indicating that COD variety as a female parent gave significantly higher fruit set compared to other varieties. Generally, the varieties WCT and CGD under selfing gave a higher fruit set (27.43 and 24.65%) when compared to inter se (21.63 and 21.22%). Fruit set was maximum (28.73%) during March and minimum (18.80%) during May but the year-to-year variation was not significant. The bimonthly average relative humidity (%), number of rainy days and rainfall (cm) had a significant negative correlation (-0.504, -0.428, -0.395, respectively) with fruit set. Studies also revealed that there was a significant reduction in fruit set to the tune of 35%, when climatic conditions are not favourable. The present investigations revealed that fruit set in coconut vary significantly due to genotype, cross combination and climatic variables.