Authors : V.D. Deshmukh , L. N. Tagad and R.S. Wagh
Page Nos : 104-112
Description :
To ascertain the role of nutrients in leaf reddening, the present field experiment study entitled, “Physiological evaluation of leaf reddening in bt and non bt cotton (gossypium spp l.) genotypes.” was conducted at PGI Farm, Mahatma Phule Krishi Vidyapeeth, Rahuri during kharif 2010-11 and 2011-12, with the objectives to study the effect of fertilizer levels and foliar sprays of chemicals on reddening of leaves of Bt and non-Bt cotton genotypes. The thirty two treatments consist of application of various levels of fertilizers to the soil and foliar sprays of N, P, K, Mg and S to plants at boll formation and development stage with three replications to Bt and non-Bt cotton hybrids and varieties were tested for the leaf reddening. The results revealed that the incidence of leaf reddening was more in Bt cotton than non-Bt cotton. The minimum intensity of reddening in Bt and non-Bt cotton was observed in the treatments of 125 % RDF + foliar sprays with KNO3/MgSO4/DAP. Among the foliar spray 2 % KNO3 had showed minimum reddening of leaves, which suggest that at boll development stage the application of nitrogen and potassium were helpful for controlling the reddening in Bt and non-Bt cotton. However, the highest yield was recorded in treatment RCH Bt + 125% RDF +KNO3 2% (V1F2T3) followed by, RCH Bt + 125% RDF +DAP 2% (V1F2T1). This study also suggested that, the nutrients were one of the causes for reddening and Bt cotton had more requirement of nutrients especially at boll development stage, which was fulfilled by the foliar sprays. Application of 125% RDF and the foliar sprays of mineral nutrients (N, P, K and Mg) through 2 % KNO3, 2 % DAP and 2 % MgSO4, had reduced the risk of leaf reddening as well as helped in increasing seed cotton yield in Bt and non-Bt cotton hybrids. The study also provides future guide line of research for various combinations of nutrients for foliar sprays for Bt cotton hybrids at different development stages, which can reduce leaf reddening and their by yield sustainability can be achieved.
