Effectiveness of Different Weedicides on Weed Biomass, Nutrient Uptake and Yield of Rice

An experiment was conducted to find out the effectiveness of different herbicides on weed biomass, nutrient uptake and yield of rice. Almix 20 WP @ 0.004 kg a.i./ha plus Butachlor 50 EC @ 0.938 kg a.i./ha applied at 3 DAT was found to be superior than all the other herbicides tested. Butachlor 50 EC @ 0.938 kg a.i./ha followed by Almix 20 WP @ 0.004 kg a.i./ha applied at 3 DAT gave slightly lower grain yield of 4.70t./ha. Among the herbicides, the lowest grain yield (3.66 t./ha) was obtained from Pyrazosulfuron-ethyl 5 WP @ 0.020 kg a.i./ha applied at 8 DAT, however, all the herbicides were significantly superior to the non weeded control. The lowest weed dry matter was found in Almix 20 WP @ 0.004 kg a.i./ha plus Butachlor 50 EC @ 0.938 kg a.i./ha applied at 3 DAT which was significantly lower than treatment receiving Pyrazosulfuron-ethyl 5 WP @ 0.025 kg a.i./ha applied at 8 DAT. The uptake of NPK by the plants followed almost the similar pattern.