Aerobic rice, Hand hoeing, Herbicides, Weed control efficiency
A field experiment was conducted at Pandit Jawaharlal Nehru College of Agriculture and Research Institute, Karaikal, Puducherry to evaluate the efficacy of different weed management practices in managing weeds of aerobic rice in the coastal areas of Karaikal. The experiment involved eleven weed management treatments laid out in randomized block design with three replications. Treatments included: four pre-emergence (pendimethalin 0.75 kg/ha, pretilachlor + safener 0.50 kg/ha, Butachlor 1.00 kg/ha and anilophos 0.40 kg/ha) and three early post-emergence herbicides (cyhalofop 0.10 kg/ha, pyrazosulfuron ethyl 0.20 kg/ha, metamifop 0.075 kg/ha, metamifop 0.100 kg/ha) followed by one hand hoeing at 40 DAS. Aerobic rice under these treatments was compared with transplanted rice given two hand weeding at 20 and 40 days after transplanting. The predominant weed flora observed in the experimental field were Echinochloa colona, Cynodon dactylon, Panicum repens, Cyperus rotundus, Trianthema portulacastrum, Cleome viscosa, Aeschynomene indica and Eclipta alba. Herbicides tested were effective in reducing the weed density and biomass and increasing the rice grain yield significantly. Pre-emergence application of pendimethalin 0.75 kg/ha + HH at 40 DAS recorded significantly higher grain and straw yields with lower weed density, weed biomass and higher weed control efficiency.