Influence of new herbicides and nitrogen levels on weed dynamics and productivity of Basmati Rice (Oryza sativa L.) in western plain zone of U.P.

Abstract

A field experiment was conducted to evaluate the effect of nitrogen levels and weed management practices on weed dynamics and performance of Basmati rice in western plain zone U.P. at Crop Research Centre, Chirori of Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut (U.P.), during kharif season 2017. The experiment was laid out in factorial randomized block design with three replications. The experiment consisted of three nitrogen levels viz.; 90, 120 and 150 kg N ha-1 and six weed management practice viz.: Bispyriback sodium 25 g a.i./ha PoE (20 DAT), Pyrazosulfuron ethyl 20 g a.i./ha PE (3 DAT), Penoxsulam 24 g a.i./ha PE (3 DAT) and Ethoxysulfuron 15 g a.i./ha PoE (6-8 DAT), weed free and weedy. Pusa basmati-6 (Pusa-1401) was used as test variety. Among the different nitrogen levels application 150 kg N ha-1 significantly better growth parameters i.e. plant height and no. of tillers at the all stages of crop growth. The highest yield attributes, grain yield (47.54 q ha-1) and straw yield (53.52 q ha-1) was recorded with 150 kg N ha-1, closely followed by 120 kg N ha-1. Whereas In case of weed dynamics the lowest weed density and biomass was recorded with 90 kg N ha-1 at all the growth stages, which was significantly lower than rest of the treatment. Among the chemical weed management treatments Bispyriback sodium 25 g a.i./ha recorded significantly higher growth parameters, yield attributes, grain yield (44.97 q ha-1) and straw yield (53.60 q ha-1). However in reference to weed dynamics Bispyriback sodium 25 g a.i./ha also recorded minimum weed density and biomass at all the growth stages and maximum weed control efficiency, which was almost at par to weed free treatment. Pyrazosulfuron ethyl 20 g a.i./ha, Penoxsulam 24 g a.i./ha and Ethoxysulfuron 15 g a.i./ha were also produced significantly less weed density, dry matter than weedy check. The highest gross return, net return and B: C ratio was obtained with 150 kg N ha-1 which was at part to the 120 kg N ha-1. Application of Bispyriback sodium 25 g a.i./ha produced significantly higher gross return, net return and B: C ratio than rest of the herbicidal treatments. The highest B: C ratio was recorded by Bispyriback sodium 25 g a.i./ha which was significantly higher than all the treatments among weed control except Pyrazosulfuron ethyl 20 g a.i./ha. Therefore it can be concluded that application of 120 kg N ha-1 with Bispyriback sodium 25 g a.i./ha was best management option to get higher yield as well as profit from Basmati rice.