The Establishment And Popularization Of Integrated Prevention And Control Technology Of Bio-organic Fertilizer On Tobacco Bacterial Wilt

Tobacco bacterial wilt,inducing the yield reduction of tobacco,is major caused by Ralstonia solanacearum.In recent years,biological control is becoming the most promising method to control this disease,keeping the sustainable development of tobacco industry.The topic was based on bio-organic fertilizer to control the wilt disease,was developed by Nanjing Agricultural University.First,The specific bio-organic fertilizer combined with deeply ploughing and calcium quicklime was applied to control the wilt disease in Changshun county,Guizhou province.Then the integrated measure was used to test the control efficiency of tobacco bacterial wilt in Pengshui county,Chongqing province.To analysis the the principle of new method,the yield,wilt disease incidence,quantify the pathogen and the microbial diversity in rhizosphere in different treatments.Finally,the large area trail of demonstration plot was established at Anshun county,Guizhou Province.The results were as follows:Establishment of comprehensive prevention and control technology:comprehensive measures,deeply ploughing and calcium quicklime,conbining bio-organic fertilizer were designed to improve the control efficiency in Changshun county,Guizhou Province The treatments were designed as Control(T1)?Bio fertilizer(T2)?Bio fertilizer combining deeply ploughing(T3)?Bio fertilizer combining deeply ploughing and calcium quicklime disinfection(T4).The effect of field trail and the change of soil microbial communities were determined and the results were as follows:The disease incidence of T2 was not significant different from that of T1(control)and the control efficiency was only 9.8%.The DI of T3 and T4 was decreased 24.3%and 68.5%when compared to T1(control)and the control efficiency was 30.8%and 61.3%,respectively.The results revealed that applying the bio fertilizer solely could not control the wilt disease,while deeply ploughing before applying bio fertilizer just had partial control efficiency,and the efficiency of applying bio fertilizer combining with deeply ploughing and calcium quicklime disinfection was the best.At the same time,the agronomic characters of T4 were significantly higher than the other three treatments.The result of 16S rDNA sequencing showed that the microbial dominance of T4 was significantly decreased,and the bacteria in the soil was more balacnced and stable when compared to control.Validation of comprehensive control efficiency:Choose the technology and method above(T4 treatment)to verify the control efficiency,Two fields with the disease incidence of 65.6%in last year were selected for the trial in Pengshui county,Chongqing,and T1 treatment and T2 treatment were seted.The results showed that the control rates of integrated measure with bio fertilizer were 68.1%and 70.5%,yields of per mu of tobacco plants increased 8.9%and 10.8%,value of per mu increased 24.9%and 25.9%,respectively.The application of bioorganic fertilizer reduced the number of Ralstonia solanacearum in rhizosphere soil significantly The number of Ralstonia solanacearum were clearly decreased by using bio fertilizer,the number were a magnitude less than the control after 40d,60d,80d respectively.Cluster analysis showed that the microbial communities were different between control and bio fertilizer treatment.It indicated that bio fertilizer integrated control measure could significantly improve soil microbial functional diversity with the prolonging of planting days.Application and demonstration of comprehensive prevention and control technology:The field trial in Anshun county,Guizhou Province was selected a severely afflicted area of 205 mu with the disease incidence of 73.2%in last year,based on the test above.Two treatments were set as Control of 5 mu and Bio fertilizer integrated measure(T2 treatment)of 200 mu,respectively.The results demonstrated that bio fertilizer could significantly prevent and control Ralstonia solanacearum and the control efficiency of the integrated measure was 76.5%.Besides,the agronomic characters and the yield of tobacco plants were significantly improved.