Bio-Efficacy of Post Emergent Herbicides on Weeds in Direct Seeded Rice (Oryza sativa L.)

Abstract

A field experiment was conducted to study the bio-efficacy of post emergent herbicides on weeds in direct seeded rice in medium black clay soil at Agricultural Research Station, Dhadesugur, University of Agricultural Sciences, Raichur, Karnataka during Kharif 2022. The experiment was laid out in Randomized complete block design with three replications. There were eight treatments consisting of five post emergent herbicides sprayed at 25 DAS, hand weeding at 20 and 40 DAS, weed free check and weedy check in direct seeded rice and the variety RNR 15048 was used in this trial. Application of cyhalofop butyl 5.1 % + penoxsulam 1.02 % OD @ 2000 ml ha-1 recorded significantly lower weed density, weed dry weight, weed index and higher weed control efficiency compared to all the other treatments. It also produced higher number of productive tillers (409.4 m-2), panicle weight (3.89 g), filled grains per panicle (243.1), lower number of unfilled grains per panicle (8.4), higher grain yield (6058 kg ha-1) and straw yield (6935 kg ha-1) in direct seeded rice. So it can be concluded that application of cyhalofop butyl 5.1 % + penoxsulam 1.02 % OD @ 2000 ml ha-1 at 25 DAS (weeds at 2-3 leaf stage) was most effective in managing the weeds with higher weed control efficiency. It also resulted in higher growth and yield components of direct seeded rice leading to higher grain yield.