Abstract: Weeds are one of the major limiting factors to the development of dry seeded rice. Therefore, the weed infestation and weed control practices were studied in field experiment. The results are as follows: 1. Weeds damaged the growth of dry seeded rice, especially in reducing yield, the number of panicle, seed setting, 1000-grain weinght and panicle length. 2. The total weed or grasses accumulated dry weight might serve as one of the weed damage indexes. 3. Grasses injured much more seriously than others,which dominated in dry seeded rice field. 4. The critical period of weed control is at 25 to 40 days after sowing. Moreover, the potentiality of weed seeds and weeding time were also discussed.

Key words: Dry seeded rice, Weed infestation, Weed management