Effect of nitrogen fertilizers and weather parameters on the incidence of jassid Amrasca biguttula biguttula (Ishida) in Bt, non-Bt and Desi cotton Devi Yendrembam K.*, Kumar Vijay, Gill Ranjit Singh Department of Entomology, Punjab Agricultural University, Ludhiana, 141004 *Email: kismon1987@gmail.com
Online published on 23 October, 2018. Abstract The effect of nitrogen fertilizers on the incidence of jassid Amrasca biguttula biguttula Ishida in Bt, non-Bt and desi cotton cultivars was evaluated at the Entomological Research Farm, Department of Entomology, PAU, Ludhiana during 2014 and 2015. The incidence was observed throughout the cropping season and its peak was during July-August. Significantly higher incidence of nymphs was observed with higher dose of nitrogen (325 kg/ha) as compared to of 162.5 and 250 kg/ha. Among the cultivars, jassid population was significantly higher on non-Bt cotton cultivar, LH 2108 (3.65 nymphs/3 leaves) during 2014 and Bt cotton cultivars, RCH 773 (5.80 nymphs/3 leaves) during 2015 as compared to other cultivars, and the least population was observed with desi cotton cultivar, FDK 124 (1.86/3 leaves) during 2014 and FDK124 (1.70/3 leaves) during 2015. The correlation coefficients between population of jassid nymphs with weather parameters revealed significant positive relationship with maximum and minimum temperature, rainfall, evening relative humidity and evaporation. Thus it was observed that incidence of jassid increases with higher dose of nitrogeneous fertilizer. Desi cotton cultivar FDK 124 has significantly lowest population of jassid nymphs over Bt and non-Bt cotton cultivars. Top Keywords Bt, non-Bt, desi cotton, jassid, nymphs, incidence, nitrogen fertilizer, temperature, rainfall, relative humidity, evaporation, correlation coefficients. Top |