A GENETIC STUDY OF SOME EARLINESS RELATED CHARACTERS IN COTTON (GOSSYPIUM HIRSUTUM   L.)

Field experiment was conducted on cotton (Gossypium hirsutum L.) varieties and lines with differing maturity to determine plant growth factor contributed to early crop maturity. Earliness was measured in term of Flowering, boll setting, length of boll maturation and crop maturity. Genotypic correlations of earliness index with different morphological traits were studied. Analysis of genotypic correlations showed that earliness index is negatively correlated with all earliness related characters. The analysis of variance indicated the importance of additive gene action for all earliness related characters except days to 50% flowering. The genotypes NIAB-78 and KARISHMA was identified as super combiner for all traits related to earliness. Among nine crosses, KARISHMA x NIAB-78 and FH-634 x SL7-9 seemed good for all earliness related characters. It has been shown that greater earliness is one of the principal manifestations of heterosis in the cotton. A maximum of 31.25% of heterosis was obtained by cross of CIM-448 x NIAB-78 and 7.469 heterobeltiosis by KMA x N-78 for earliness index. These hybrids also showed negative heterosis for other earliness related characters