Genetic variability investigations on early maturity indicators and their inter-relationships in upland cotton (Gossypium hirsutum L.) cultivars

Abstract

Cotton breeding programs aim to develop early-maturing varieties that yield high. Towards this, a study was conducted at the Agricultural Research Station, Dharwad farm, during kharif 2021-22 comprising 20 genotypes. Thirteen early maturity-related traits, along with seed cotton yield were analyzed. The examination indicated significant disparities in the early maturity traits viz., days to first flower (DFF), days to first boll opening (DFB), per cent crop harvested at the first (PCH-1) and second pickings (PCH-2), Bartlett’s Index (BI), node number of the first fruiting branch (NNFFB), plant height (PH), earliness percentage (EP), mean maturity date (MMD) and production rate index (PRI). Some traits, including PCH-1, PCH-2 and PRI presented higher estimations of GCV and PCV, along with high heritability and genetic advance, making them reliable indicators for selection. Seed cotton yield showed a significant negative correlation with DFF, DFB and MMD. Conversely, it showed a significant positive correlation with the PRI, PCH-1, PCH-2 and BI. Furthermore, DFB and PRI exhibited highly significant direct positive effects, while DFF had a negative direct effect, followed by the FBP. Based on this study, the genotypes ESS-3, ESS-20, NNDC-30 and S-32 were identified as early-maturing compared to ESS-13, FLT-25 and URT-21. These genetically diverse genotypes can be valuable resources for forthcoming cotton breeding programs.

Keywords

• cotton
• early maturity
• seed cotton yield
• bartlett’s index