Effect of Buckwheat (Fagopyrum esculentum Meonch) Leaf Extract on Weeds Grown in Winter Rice under North Bengal Conditions

The aqueous leaf-extract of buckwheat (25 g of air dried leaves in 1000 mL of water) was applied on wafer rice @ 1700 L ha⁻¹. The other treatments were hand weeding, herbicide application (cinmethylin @ 100 g ai ha⁻¹) and no weeding. The extract and the herbicide were applied on the 5^th day after transplanting. The leaf-extract of buckwheat inhibited the germination of weeds including Oxalis, Cyperus and Fimbrystylis. The dry weight of weeds id buckwheat treated plots was significantly lower than that found in control plot. This result was almost at par with the result found in the cinmethylene treated plot. The average yield also significantly increased in the buckwheat treated plots.