Field Application Technology Research On New Medicament For Controlling Bacterial Blight Of Rice

Rice bacterial leaf blight is an important disease in the world. Rice bacterial leaf blight is vascular bundle disease caused by Xanthomonasoryzaepv. oryzae(Xoo). For a long time, the chemical control of leaf blight of rice leavesrely mainly on bismerthiazol and thiediazole copper which had been reported in recent years that control effect is not ideal. There is an urgent need to develop and apply new fungicide.2-(methylsulfonyl)-5-(4-fluorobenzyl)-1,3,4-oxadiazole developed by Research and Development Center for Fine Chemicals of Guizhou university was a new fungicide. The research studied the application technology of 20% 2-(methylsulfonyl)-5-(4-fluorobenzyl)-1,3,4-oxadiazole SC in controlling rice bacterial leaf blight in the field.The study used indoor seed dressing test with 20% 2-(methylsulfonyl)-5-(4-fluorobenzyl)-1,3,4-oxadiazole SC to study its influence on seed germination and seedling quality. Seed dressing experiment’s results showed that the germination rates of rice seeds were about 25% and 55% respectively at the dose of 2-4 g/kg treatment with 20% 2-(methylsulfonyl)-5-(4-fluorobenzyl)-1,3,4-oxadiazole SC in culture dishs, on the 3th and 7th days, and the germination rate was about 10% at the dose of 8-16 g/kg. The germination rate of the group with 20% bismerthiazol WP treatment was about 98%. In the pot experiment, the germination rate was about 89% at the dose of 2-8 g/kg treatment with 20% 2-(methylsulfonyl)-5-(4-fluorobenzyl)-1,3,4-oxadiazole SC on the 7th day, which had no significant difference with 20% bismerthiazol WP treatment group. About the pot experiment, there was light impact when the dose of treatment is lower than 8 g/kg, and 20% 2-(methylsulfonyl)-5-(4-fluorobenzyl)-1,3,4-oxadiazole SC may degrade in soil.The control efficiency of field’s plot experiment against rice bacterial leaf blight was better than other doses with 20% 2-(methylsulfonyl)-5-(4-fluorobenzyl)-1,3,4-oxadiazole SC at 75 g/mu. The control results of field with 20% 2-(methylsulfonyl)-5-(4-fluorobenzyl)-1,3,4-oxadiazole’s 66.30% and 43.05% were higher than that of 3% zhongshengmycin WP’s 45.01% and 38.34 at 50g/mu respectively.It established two experimental demonstrations to carry out the prevention and control demonstration work on rice bacterial leaf blight with 20% 2-(methylsulfonyl)-5-(4-fluorobenzyl)-1,3,4-oxadiazole SC in Mangshi of Dehong Prefecture,Yunnan Province. The aera was 100 mu respectively. The control efficiencies of field with 20% 2-(methylsulfonyl)-5-(4-fluorobenzyl)-1,3,4-oxadiazole SC at 75 g/mu and 3% zhongshengmycin WP at 50 g/mu were 42.78% and 32.65% respectively in the Manghe demonstration. By two paring experimental methods in the field, the best control efficiencies of field with 20% 2-(methylsulfonyl)-5-(4-fluorobenzyl)-1,3,4-oxadiazole SC, 20% bismerthiazol WP and 3% zhongshengmycin WP were 54.18%, 34.05% and 26.11% respectively in the Tuanjie demonstration.The research results provided technical parameters for the application by controlling rice bacterial leaf blight with 20% 2-(methylsulfonyl)-5-(4-fluorobenzyl)-1,3,4-oxadiazole SC.