Kulvir Singh, Sudeep Malik, Pankaj Rathore and Sukhjinder Singh
Abstract
Field experiments were conducted at Faridkot and Bathinda during Kharif 2013 to study the effect of foliar application of nutrients on amelioration of leaf reddening, growth and yield of Bt cotton. The experiment laid in randomized block design replicated thrice had eight foliar treatments {i.e Control, KNO3 @2%, MgSO4@1%, MgSO4@0.5%, MgSO4@1.5%, MgCl2@1%, Mg(NO3)2@1% and KNO3 @2% + MgSO4 @1% sprayed during flowering & boll development stage}. Mean data indicated highest seed cotton yield (3064.0 kg/ha) with application of MgSO4@1.5%as compared to other treatments primarily due to reduction in leaf reddening (8%) besides improved sympods, boll weight and bolls per plant. Lab studies verified that reduced magnesium concentration below the sufficiency range was responsible for leaf reddening. Foliar sprays of magnesium sulphate @1.5% twice during flowering and boll development stage was found to be most effective in ameliorating the red leaf incidence and significantly enhanced cotton productivity.