Effect of harvesting time in seednut characters in coconut

Abstract

On the west coast of India, seednuts are being harvested during the summer months (February to May). The present investigation was mainly to know whether the nuts harvested through out the year can be used for seednut purpose in komadan. An attempt was also made to find out the effect of season on the floral characters in the two varieties. Study on the effect of season on the manifestation of the various floral characters revealed that, in both Komadan and WCT, during February to May there was higher production of bunches having proportionately more female flowers resulting in higher nut yields. The study on mother palm characters revealed that the Komadan variety exhibited superiority over WCT in number of spadices per palm per year, number of nuts per bunch and annual nut yield per palm. Correlation studies in mother palm characters revealed that the principal yield components in Komadan were number of nuts per bunch, number of bunches per season and percentage fruitset, while in WCT, high yields were the resultant effect of number of nuts per bunch, number of female flowers per spadix, number of bunches per season, total number of female flowers and number of spadices. It was also observed that in both varieties when the number of female flowers per spadix increases the retention percentage gets reduced. Most of the correlations between floral and yield traits studied were found to be homogeneous at different times of harvest in both varieties, with more homogeneity in Komadan. Study on the effect of harvesting time on seednut characters revealed that February to May (hot weather periods) is the best period for seednut collection in both WCT and Komadan. This is based on the fact that the important seednut characters like copra content per nut, kernel weight, size of nut, husked nut weight and seednut quality index were found to be at its maximum for nuts harvested during summer months in both WCT and Komadan. The Komadan variety was found to be significantly superior to WCT in four seednut characters viz., weight of kernel, copra content per nut, weight of embryo and volume of nut water. Varietal difference affected only a very limited number of correlations among seednut characters. Most of the inter correlations among seednut characters were found to be homogeneous at different times of harvest in both Komadan and WCT. In both Komadan and WCT, among the seednut characters, weight of kernel was found to be highly correlated with copra content. Oil content was not correlated with any of the seednut characters in Komadan. But in WCT, it was found to be negatively correlated with kernel weight. Among the 15 seednut characters studied, five characters viz., equatorial diameter, weight of unhusked nut, weight of husked nut, weight of kernel and oil content contributed 90 per cent of the total variation explained by the 15 seednut characters on copra content per nut, in both Komadan and WCT. In both Komadan and WCT, the very limited variability for oil content was explained by the 15 seednut characters studied. In Komadan, yield of nuts was negatively correlated with equatorial diameter of nut, weight of unhusked nut and weight of husked nut. But in WCT, yield of nuts was negatively correlated with almost all seednut characters. Based on seednut qualities, hot weather periods (February to May) were found to be the most suitable time for seednut collection in both Komadan and WCT.