Chemical control of weeds in transplanted rice.
Post-em. herbicides were evaluated in transplanted rice in the irrigated basin of River Mombo in northern Tanzania. The predominant weeds were Cyperus difformis, Pycreus macrostachyos, Echinochloa colonum, Ammania baccifera, Ludwigia abyssinica and Ipomoea aquatica. Basagran PL2 (bentazone + propanil) at 4 and 5 kg a.i./ha gave the best weed control and hand-weeding was next best. The performance of butachlor at 2 and 3 kg/ha, NC 20484 [2,3-dihydro-3,3-dimethyl-5-benzofuranyl ethanesulphonate] at 0.25 and 0.5 kg/ha and molinate at 3.6 kg/ha was disappointing. No herbicide adversely affected the quality or yield of grain.