Toxicity Determination and Control Effects of Server Fungicides Against Corn Top Rot Disease Pathogens

The corn top rot caused by Fusariurn subglutinans is a new disease on corn production in China. There were seldom domestic researches and system research reports and effective measures against the disease. Inhibition effect of 8 fungicides on Fusariurn subglutinans was measured. The results showed that the EC50of 25 g/L fludioxonil floating suspeusion(FS) was the smallest. The sensitivity of pathogen to this fungicide was the highest, and its inhibitory effect was best. The EC50of 60 g/L tebuconazole FS and 80% carbendazim wettable power(WP) were smaller, the sensitivity of pathogen to them was higher, and their inhibitory effect was better. The EC50of 97% dimethomoph WP was the largest, the sensitivity of pathogen to it was the lowest, and its inhibition effect was the worst. The greenhouse seed coating suggested that the 25 g/L fludioxonil FS and 60 g/L tebuconazole FS could be applied in the control of the corn top rot. At the same time, the indoor toxicity experiment research has further defined the effects of different toxin filtrates of Fusariurn subglutinans on corn radical and germ growth by different treatment of fludioxonil, tebuconazole and carbendazim.