Comparative study of effectiveness of herbicides as pre-and post-emergemce in pre-germinated direct-seeded rice [1988-1989]
1990
Prasan Vongsaroj | Jamras Lekham | Thongchai Kengwa (Department of Agriculture, Bangkok (Thailand). Botany and Weed Science Div. Weed Science Group)
Comparative study of petrilachlor, metsulfuron-methyl, bensulfuron-methyl, piperophos/dimethametryn and butachlor was done at the rates of 120, 1.5, 8.0, 120 and 160 g. a.i./rai. Herbicides were applied at 3 days before seeding (DBS) and 10 days after seeding (DAS). The trials were conducted at Suphan Buri Rice Experiment Station and Chai Nat Rice Experiment Station as split plot design. The toxicity to rice, grade of weed control were recorded as well as the height of rice at harvest, number of panicles/0.5 square meters and yield of rice. At Suphan Buri, toxicity to rice for the treatments of application at 3 DBS tended to be less than those at 10 DAS except bensulfuron-methyl. Grades of weed control were identical between two application times of herbicide and among herbicidal treatments in each time of application. At Chai Nat, the results in wet season in term of the toxicity to rice were the same between the times of application and among herbicidal treatments piperophos/dimethametryn had highest toxicity. Grades of weed control at 3 DBS and 10 DAS were almost the same resulting in no difference in yield. For the dry season, it was found to be similar to the wet season in case of toxicity to rice and weed control. The yields were the same between two application times but not in each application time.
显示更多 [+] 显示较少 [-]