Weed populations in transplanted and wet‐seeded rice as affected by weed control method

There was little difference in the weed flora between transplanted and wet‐seeded rice (Oryza sativa L.). The weed control methods used greatly influenced the weed flora. Echinochloa glabrescens Munro ex Hook.f. was dominant in the unweeded and herbicide‐treated plots while Monochoria vaginalis (Burm. f.) Presi was dominant in the hand weeded plots. Weed weights were similar in both planting methods. Weed weight was reduced and rice yield was increased by hand weeding and herbicide treatments but the efficiency of weed control with herbicides decreased due to the buildup of weeds in the later plantings.