The predominant weed flora in the experimental field were Echinochloa colonum, Commelina benghalensis and Caesulia axil/aris and Cyperus rotundus. Highest nutrient uptake by rice 28.09, 8. 09 and 68.76 kg ha −1 nitrogen, phosphorus and potassium, respectively was recorded from 20 June sown crop. Use of herbicides increased nutrient uptake by rice and decreased nutrient uptake by weeds. Uptake of nutrients was higher by rice and lowest by weeds with hand weedings twice and pre-emergence application of pendimethalin at 1000 g ha −1 + anilophos at 400 g ha−1 over rest of the treatments. Reduction in grain yield due to weed competition was 70.4 and 67.4 percent in weedy plots.
direct seeded rice, weed management, date of sowing, nutrient uptake
