Studies on Biological Characteristics and Indoor Fungicides Toxicity Evaluation of Cowpea Root Rot Pathogen

The biological characteristics and fungicides toxicity evaluation of the pathogenic fungus causing cowpea root rot pathogen in Hubei province were studied. The results showed that the optimum temperature for the mycelial growth were 25~ 35 ℃, the optimum pH for mycelial growth were pH 6~9, and light promoted the growth of mycelial. The pathogen could make use of various carbon and nitrogen sources, and the best carbon source was maltose while the best nitrogen source was sodium nitrate. The lethal temperature for mycelial growth was 65 ℃ for 10 min. The results of indoor fungicides toxicity eval- uation showed that the toxicity of 70% thiophanate methyl superfine wettable powder was the strongest to Fusarium solani, followed by 50% sulfur carbendazim wettable powder and 40% Fuxing EC. These 3 fungicides can be used to control cowpea root rot pathogen. The EC50 values of 80% carbendazim wettable powder and 10% difenoconazole were lower than that of oth- er fungicides, which could be used to control cowpea root rot pathogen as well.