Biennial tendency among coconut hybrids a stastical study

Abstract

The present study deals with the objective of estimating the magnitude of biennial tendency among coconut hybrids and WCT and to test for their significance. Non parametric and parametric approaches were tried for the study. The intensity of crop fluctuations was also estimated. The magnitude of biennial tendency was 100 per cent, 52.26 per cent and 84.34 per cent respectively for the WCT palms taken from RARS, Pilicode; RARS, Kumarakam and CRS, Balaramapuram. 100 per cent bienniality was observed for the WCT palms which were subjected to NPK manuring and for the hybrid varieties NCD, LO x GB and CC x GB palms. 97.59, 94.12, 80, 83.33, 80, 71.42, 66.67, 95.69, 88.89 and 25 per cent of the palms of WCT x CDG, WCT x GB, AO x GB, Java x GB, LS x GB, T x G, T x SS, T x D, T x GB and komadan exhibited biennial tendency. T x AD and T x LD palms showed only 14.29 per cent bienniality. Intensity of crop fluctuations was less than 50 per cent for almost all these varieties. The distribution of palms in the ‘on’and ‘off’ phase also established the existence of biennial tendency. The test of significance of biennial tendency established the existence of biennial tendency established the existence of biennial tendency among all the WCT and hybrid palms except for T x AD and T x LD. The time-trend was not found to be a significant characteristic for almost all the varieties. WCT palms which were subjected to fertilizer management during the period of the study and WCT x cdg palms were found to be influenced by both the time-trend and biennial tendency.