Development Of A Bio-control Formulation Against Phytophthora Capsici

Pepper blight is by caused Phytophthora capsici,a soil borne disease,all of pepper production places have happened in our country.And in the whole growth period can harms pepper's stem,leaves and fruit,make the deep cuts,and even failures,bring the serious damage to the production of hot pepper.This Phytophthora capsici was isolated from the fields of pepper blight in Tayang Qionghai,antagonistic activity were determined through the confrontation experiment of actinomycetes BM10 and WZ60,and the secondary fermentation conditions were optimized by using single-factor and orthogonal test,the carrier of two stains were screened,Complete basic research of inoculants.Finally,qualitative analysis of indoor and field experiments,the effect of preventing of two actinomycetes were studied,the results are as follows:(1)Phytophthora capsici isolated by the organization bait method,and identified from morphological and physiological characteristics.(2)Antagonistic activity were determined through the confrontation experiment,the results show that both strains to Phytophthora capsici have obvious inhibitory effect.The Phytophthora capsici was inoculated on each plate containing actinomycetes BM10 and WZ60 broth,Phytophthora capsici could not grow,indicating that the two antibiotics from the actinomycetes metabolism have strongly inhibited on Phytophthora capsici.(3)The secondary solid-state fermentation conditions were optimized by using single-factor and orthogonal test.The results showed that the optimal conditions for the secondary solid-state fermentation of the WZ60 strain included a medium composed of water,soybean flour,corn flour,wheat brain,sandy soil and rice at a ratio of 120:7:7:10:40:100 by weight,fermentation time 8 d at 28 ?,medium volume in 100 mL flask 50 g;And as to BM10,the optimal conditions that included a medium composed of water,soybean flour,corn flour,wheat brain,sandy soil and rice at a ratio of 150:7:10:10:40:100 by weight,fermentation time 8 d at 28 ?,medium volume in 100 mL flask 50 g.(4)The carrier of organic fertilizer and cultivated soil at the ratio of 1:1 mixing by weight proved to be the best for formentation products of actinomycetes BM10 and WZ60.The amount of viable propagules were 22.4 X 107cfu/g and 14.6 X 107cfu/g of actinomycetes BM1O and WZ60 afer six month.(5)Qualitative analysis of the effects of actinomycetes BM10 and WZ60 on Phytophthora capsici by using detached leaves,the results show that two actinomycetes have effect on Phytophthora capsici,and solid-state agents of prevention is better than broth control effect.(6)The field contrast control effect test data results show that the two stains have effect on Phytophthora capsici,solid-state agents control effect was 61.5%,which is quite metalaxyl control effect,composite microbial agent control effect is better than single agents.