Interactive Effect of Different Nitrogen and Potash Levels on the Incidence of Bacterial Leaf Blight of Rice (iOryza sativa L./i)

摘要

An experiment was conducted at Rice Research Institute, Kala Shah Kaku in 2010 during kharif season to study the influence of nitrogen (N) and potash (K) on severity of Bacterial leaf blight (BLB) of rice (Oryza sativa L.) aimed at improving productivity. The experiment was laid out in randomized complete block design with factorial arrangement with three replications. Treatments comprised of: 0 kg N ha-1, 75 kg N ha-1, 100 kg N ha-1, 125 kg N ha-1 and 0 kg K ha-1, 50 kg K ha-1, 75 kg K ha-1, 100 kg K ha-1. Data on disease severity and paddy yield were recorded using standard procedures. Paddy yield was affected significantly by various combinations of N & K. In case of bacterial leaf blight, minimum diseased incidence percentage was observed when nitrogen alone was applied @ 75 kg·ha-1 in contrast to fertilizer applied @ 125 kg N ha-1 + 50 kg K ha-1 which showed maximum diseased incidence percentage. Maximum paddy yield (4.32 t·ha-1 ) was recorded when rice was fertilized @ 75 kg N ha-1 + 100 kg K ha-1 as compared to sole fertilization of 75 kg K ha-1 that produced minimum paddy yield (2.40 t·ha-1). Maximum gross income, net returns and benefit cost ratio were obtained where rice crop was fertilized @ 75 kg N ha-1 and 100 kg K ha-1.