Heterosis for yield and its components in Asiatic cotton hybrids based on GMS system under varied environments

Abstract

Efforts are now being made to explore heterosis in Asiatic cotton for further increase in productivity. A desi cotton hybrid LOH 11 has been released for general cultivation in North Zone. The use of male sterility system can reduce the cost of hybrid seed production considerably [1]. Therefore, in the present study, 30 GMS based hybrids were evaluated under varied environmental conditions to study the economic heterosis and to identify the suitable combination for commercial exploitation. Hybrids were developed between OS-5 GMS line and 30 male parents of Asiatic cotton selected from germplasm. Thus 30 genotypes alongwith OS-5 were sown during 1993-94 at two locations viz. Hisar and Sirsa with three level of spacing 67.5 x 45 cm., 67.5 x 60 cm. and 67.5 x 75 cm, at each location, thus creating six different environments (E1 to E6). Oata were recorded on five competitive plants randomly selected in each replication of each experiments on plant height, number of monopods, number of sympods, number of bolls/plant, boll weight, seed index, lint index and seed cotton yield. Economic heterosis was calculated for all the characters by taking greater value either at normal spacing or broad spacing of standard check OS-5 and its significance was tested as per method proposed by Wyanne et al. [2].