Fungicide And Insecticidal Activity Of The Extracts From Husk Of Carya Cathayensis Sarg.

The fungicide and insecticidal activity of the methanol extract from husk of Carya cathayensis Sarg. was studied by a systematic way in vitro and pot test with Botrytis cinerea, Alternaria solani et al 18 kinds of fungi. The insecticidal activity to Plutellu xylostella, Mythimna separatea et al 3 kinds of insects. The results are as follows: 1. The methanol extract of the husk of Carya cathayensis Sarg. could completely inhibit the hypha growth of Colletotrichum lagenarium, Sclerotinia Sclerotiorum(Lib.)de Bary, Valsa mali, Phytophora capsici under the concentration of 0.1g.mL-1. The extract of the husk of Carya cathayensis Sarg. had the highest inhibition rate to the hypha growth of Rhizoctonia solani (EC50=0.0298g.mL-1). Furthermore, the extract had more than 70% inhibition rates to the spore germination of Botrytis cinerea and Exserohilum turcicum under the concentration of 0.1g.mL-1.2. The results of pot test indicated that the extract from husk of Carya cathayensis Sarg. had 85.40% protective efficacy and 36.72% curative efficacy to B. cinerea; 75.00% protective efficacy and 66.67% curative efficacy to wheat powder mildew; 62.96% protective efficacy and 74.07% curative efficacy to Cucumber Powder mildew; 56.62% protective efficacy and 23.08% curative efficacy to Cucumber Downy mildew. Furthermore, the results showed that there isn't good correlation between efficacy in vitro and efficacy in vivo.3. The extract of the husk of Carya cathayensis Sarg. had 88.20% death rate against aphid with LD50 values 0.0428 g.mL-1. The death rates of Plutellu xylostella and Prodenia litura Fabricius were 23.40% and 9.81% under the concentration of 1g.mL-1; but it nearly had no efficacy under other concentrations. Meanwhile, it had no insecticidal activity to Tetranychus cinnabarnus under any concentration in this test.