Toxicity and field control efficacy of four fungicides against Sclerotium rolfsii

The mycelium growth rate was used to determine the toxicities of tebuconazole,prochloraz,fludioxoniland kresoxim-methyl to Sclerotium rolfsii,and field trials were conducted to investigate the control efficacy of four fungicides by seed dressing and irrigation pier in fruiting stage.Four fungicides could significantly inhibit the mycelia growth of Sclerotium rolfsii,and the EC 50 values were 0.05,0.03,0.22 and 0.61 mg/L respectively.The control effects of irrigation pier treatments of four fungicides were better than seed dressing in field trials.The control effect of tebuconazole was relative higher,with 62.91-74.93 % by seed dressing,and 68.60-82.87% by irrigating pier.All treatments could strongly increase the peanut yield and the growth rare of irrigation pier treatment was higher than that of seed dressing treatment.The yield growth rate of tebuconazole treatment was the highest with 10.74-11.55% increase.