The toxicities and effects text of seven fungicides on Pythium aphanidermatum

The toxicities of seven fungicides were tested by using mycelia growth rate method and inhibiting method of the formation of sporangium. Potted plants test were adopted by using seed treatment to test the control effect of Pythium aphanidermatum. Laboratory toxicity tests results indicated that the effects of these fungicides were significantly different in inhibiting the growth of mycelium and the formation of sporangium of P.aphanidermatum. Cymoxanil mancozeb, Mancozeb and Propamocarb had the better inhibiting effect on the mycelia growth and the EC50 values of these fungicides were 1.28, 1.28, 3.26 mgL-1. While in the inhibiting experiment of the formation of sporangium of P.aphanidermatum, Pyraclostrobin, Cymoxanil mancozeb and Mancozeb performed well with the EC50 value 0.09, 0.21, 0.46 mgL-1. After taking Fungicide seed treatments, all of tall fescue germination rate had different degrees of improvement, and Cymoxanil mancozeb and Mancozeb had the better control effect. Based on the results of the laboratory toxicity tests and pot tests, it's concluded that Cymoxanil mancozeb and Mancozeb on Pythium disease control effect is better than in the other five kinds of fungicides.