Abstract
Crop injury by Pyributicarb was evaluated in direct-seeded rice plants, depending on the seeding depth and application time. On the other hand, crop injury in combinations with dymron or dimepiperate was also evaluated in rice plants at 1cm seeding depth. Pyributicarb caused some crop injury in rice plants seeded on the soil surface on different application times (Fig. 1-a, b). However, pyributicarb did not cause a significant crop injury in direct-seeded rice plants at 1cm depth under the soil surface by the application of the standard dose (630g a. i./ha), more than 6 days (2 leaf stage) after seeding (Fig. 1-d, 2-c, d, 3-c, d). It is considered that pyributicarb does not injure rice plants seeded under the soil surface, because their rooting parts are not exposed to the chemical. In the case of combinations, dymron was effective in decreasing the crop injury of pyributicarb in rice plants seeded under the soil surface (Fig. 2-a, b), while dimepiperate did not significantly decrease the crop injury by pyributicarb under such conditions (Fig. 3-a, b). In conclusion, pyributicarb could be used as a paddy herbicide for direct-seeded rice cultivation.