The Identification To Pathogen Of Processing Chili Pepper Root Rot Disease And Its Control Fungicide Screen In Xinjiang

Objective: To clear the pathogen species of processing chili pepper root rot disease in Xinjiang and select effective biological and chemical pesticides. For technical foundation for the control of processing chili pepper root rot in Xinjiang.Method: A total of 211 processing chili pepper root rot disease samples were collected from different main production areas in Xinjiang.A total 161 isolates were obtained by tissue isolation and their pathogenicity were determined according to Koch’s rule. The raletively efficient chemical and biological agents screening by pot experiment. To research the control mechanism of biological agent against F. oxysporum by means of surveying the inhibition of biocontrol bacteria filtrate against pathogens.Results:1. A total of 221 processing chili pepper root rot disease samples were collected from pepper fields in the Yanqi, Shihezi etc 19 pepper production area. 161 isolates were obtained by tissue isolation,including 121 Fusarium.sp. accounted for 74.2% of the total isolates, and their pathogenicity were determined according to Koch’s rule.The results showed that 121 Fusarium.sp. were Fusarium oxysporum,Fusarium solani, Fusarium sporotrichioides, Fusarium moniliforme, Fusarium brachygibbosum and Fusarium fujikuroi respectively. Accounted for the isolates 47.11%, 19.01%, 7.44%, 9.09%, 9.91% and7.44%, respectively. The pathogenicity test showed that F.oxysporum and F.solani were the major pathogen of processing chili pepper root rot disease in Xinjiang.2.Toxicity test results show that all 4 kinds of pesticides inhibited the pathogenic bacteria of processing chili pepper root rot disease, EC50 size from small to big was as follows, triadimefon WP, ethylicin EC,carbendazim WP, evil mildew and thiram WP, agent concentration are 0.2283mg/L, 0.3296mg/L,2.0937mg/L and 20.5687mg/L, respectively.3.The results of pot experiment suggests that the control effect of 80% ethylicin EC 800 times was 77.29%and 15% triadimefon WP 400 times was 73.97%, which were significantly higher than the other three pesticides, The control effect of B. subtilis S44 suspensions was 51.29%, a week after applying pesticide.Two weeks after applying pesticide, control efficiency of 80% ethylicin EC 800 times was 68.13%,then control efficiency of 15%triadimefon WP 800 times was higher than 50%, and the control effect of B.subtilis S44 suspensions was 36.65%. Three weeks after applying pesticide, the control effect of B. subtilis S44 suspensions was the best, as much as 47.76%, the control efficiency of 80% ethylicin EC and15%triadimefon WP were lower than 50%.4. The antibacterial mechanism of B. subtilis S44 shows that the production of antimicrobial peptides is the main mechanism of antimicrobial activity.Conclusion:The F. oxysporum and F. solani are the major pathogen of processing chili pepper root rot disease in Xinjiang. The 80% Ethylicin EC,15% triadimefon WP and B. subtilis S44 fermentation both can be used as the main control agent for the prevention and control of processing chili pepper root rot disease.The main control mechanism of B. subtilis S44 is production of lipopeptide antibiotics.