Improvising cotton (Gossypium hirsutum L.) genotypes for compact plant architecture traits suitable for mechanical harvesting

The study aimed to improve cotton genotypes by developing early maturity and compact plant architecture traits for suitability to high density planting and mechanical harvesting. Ten F1 populations from five cotton genotypes of Indian origin were developed using a half-diallel mating and evaluated in two seasons (kharif, 2022, and Summer, 2023). Results indicated significant genetic variation for all the studied traits, enabling selection and improvement. Combining ability effects interacted significantly with environments. The mean performance of genotypes differed significantly (p <= 0.05), with hybrids outperforming parental genotypes, exhibiting shorter stature and early maturity. The parents, TVH002, and C017 were the best combiners indicated in the hybrids, TVH002 x CO17, and TVH002 x Suraksha for compact plant architecture traits. Non-additive gene action prevailed, as specific combining ability (sca) variances surpassed general combining ability (gca) variances for most studied traits. Genetic components, ratios and heritability revealed that both additive and dominant genes governed the traits, with dominance having a greater influence. Compact architecture traits negatively correlated with seed cotton yield within the 75 to <120 cm height range, resulting in a more stable yield. These findings offer valuable insights for targeted breeding programs aiming to develop compact cultivars with enhanced traits for mechanization and high density cotton plating.