Growth and yield of Bt cotton (Gossypium hirsutum L.) as affected by nitrogen, phosphorus and potassium under irrigation condition

Abstract

An experiment was conducted at Cotton Research Station, Junagadh Agricultural University, Junagadh during kharif season of two consecutive years 2006-07 and 2007-08 to study the "Effect of nitrogen, phosphorus and potassium on growth and yield of Bt cotton under irrigated conditions" on medium black clay soil. The experiment comprising three levels of nitrogen viz., 160, 200 and 240 kg N/ha, two levels of phosphorus viz., 0 and 50 kg P₂O₅/ha and four levels of potassium viz., 0, 60, 90 and 120 kg K₂O/ha. The results revealed that application of 240 kg N/ha produced significantly higher seed cotton (4027 kg/ha), lint (1432 kg/ha) and stalk yields (5589 kg/ha) than lower levels of nitrogen. Increase in nitrogen level from 160 to 240 kg N/ha appreciably improved the growth and yield attributing characters viz., plant height, plant spread, number of monopodial and sympodial branches /plant, number of bolls/plant, boll weight and number of seeds/ boll. Application of 50 kg P₂O₅/ha recorded higher values of growth and yield attributing characters and yields over control. Seed cotton, lint and stalk yields, growth and yield attributing also increased significantly with 120 kg K₂O/ ha over control.