Effect of nitrogen levels and weed management practices on growth, yield and uptake of rice under aerobic conditions

Abstract

A field experiment was conducted during kharif season of 2010 at Birsa Agricultural University, Ranchi, to find out the effect of nitrogen levels and weed management practices on the performance of aerobic rice. The experiment was laid out in split plot design with three replications and three nitrogen levels in three main plots, while seven weed control methods in sub-plots. Application of 125kg N/ha gave significantly higher plant height (88.89 cm), tillers/m2 (288), panicles/m2 (266), grains/panicle (95.41), 1000 grain weight (23.72 g), grain yield (38.98 q/ha), straw yield (57.78 q/ha), nitrogen, phosphorus and potassium uptake which ultimately resulted in significantly higher net return (`29496/ha) in aerobic rice. However, it was statistically at par with 100 kg N/ha. Among the weed management practices, application of Dhaincha in between rice row+ Pendimethalin P.E. @ 0.75 kg a.i./ha + 2,4-D @ 0.8 kg a.i./ha at 25 DAS produced significantly maximum plant height (92.3 cm), tillers/m2 (300), panicles/m2 (295), filled spiklets/panicle (98.13), 1000 grain weight (23.96 g), grain (43.73 q/ha), straw yield (61.68 q/ha), nitrogen, phosphorus and potassium uptake as well as net return (`34405/ha) and B:C Ratio (2.22) in aerobic rice.