Heterosis studies for seed cotton yield and its components over environments in cotton

An investigation was carried out using ten lines and five testers in a line x tester mating design to estimate the nature and magnitude of heterosis for seed cotton yield and its components in cotton. The resulting 65 genotypes including parents along with a check hybrid (G-Cot.Hy-12) were evaluated in a Randomized Block Design with three replications under three dates of sowing (environments) i.e. E1 = Onset of monsoon, E2 = 20 days after 1st sowing and E3 =20 days after 2nd sowing. The pooled analysis of variance for the experimental design revealed significant differences among the genotypes, parents, hybrids and parents vs hybrids for all the characters. Remarkable levels of heterosis and heterobeltiosis were observed for seed cotton yield per plant and most of the characters studied. The heterobeltiosis and standard heterosis ranged from -37.93 to 44.44% and -44.99 to 81.98% in pooled analysis. The crosses GJHV 500 x GTHV 7/70, G. Cot 18 x GSHV 173, G. Cot 12 x GSHV 173 and GJHV 536 x GTHV 7/70 which manifested significant and desirable heterobeltiosis and standard heterosis for seed cotton yield per plant also recorded significant and positive heterosis for plant height, number of sympodia per plant, number of bolls per plant and boll weight.