Growth and yield performance of cotton (Gossypium hirsutum) expressing Bacillus thuringiensis var. Kurstaki as influenced by polyethylene mulching and planting techniques

Abstract

Field experiment was conducted during 2006–08 winter (August – February) cropping season to study the growth and yield performance of cotton expressing the Bacillus thuringiensis (Bt) and non-Bt genotypes of ‘RCH 20’ due to mulching and planting techniques. Three methods of planting, viz single row, triangular and double row (paired row) were compared. Irrespective of the genotypes, double row planting with 22 222 cotton plants/ha yielded significantly higher seed cotton yield (4 181) than other methods of planting. However, in terms of seed cotton equivalent yield, triangular planting with 11 111 plants of cotton and the equal number of intercrop radish (Raphanus sativus L.) was at par with double row planting of cotton. Among the genotypes, Bt cotton ‘RCH 20’ yielded significantly higher yield (4 328) than its non-Bt counterpart. Polymulching benefited both-Bt and non Bt cotton, while the benefit was more for Bt cotton with 56.4% higher yield as against 34.2% enhanced yield for non-Bt cotton. The available soil moisture in 0– 45 cm soil depth recorded during periodic soil sampling was higher (24.9%) under polymulching as compared to lower (19.8%) available soil moisture under conventional method. The enhanced soil temperature of 3.9–4.0°C recorded under polymulching in the 0–15 cm soil depth was favourable for faster mineralization and mobilization of nutrients in the soil.