Control Effect Of Seed-treated With Antagonistic-Actinomycetes KF-5-1 On Verticillium Wilt Of Cotton

Verticillium wilt is one of the most threatening diseases in cotton production,which can cause morbidity in the whole growth period of cotton and lead to the decline in cotton yield and fiber quality.In this study,the virulence of the actinomycetes KF-5-1 isolated from the laboratory was determined,and its antibacterial effect was preliminally tested.Cotton Verticillium wilt antagonistic actinomycetes KF-5-1 was mixed with cotton pesticide to produce seed coat agent,and its control effect was investigated in laboratory and field,providing theoretical basis for biological control of cotton Verticillium wilt.The main results are as follows:(1)The bacteriostatic effects of the KF-5-1 strain and three kinds of agents sold on the market were measured by an indoor virulence test.The results showed that the bacteriostatic effect of antagonistic KF-5-1 was good,up to 77.58%,which provided a theoretical basis for the comprehensive control of Verticillium wilt of cotton by using antagonistic seed coat agent in the later field.(2)Verticillium wilt The results showed that KF-5-1+allicin treatment could significantly increase the seedling emergence rate by 20.52%compared with CK.The shortest germination time was 11 hours under KF-5-1+ethallicin treatment.Compared with the control group,the shoot length,shoot fresh weight and root length of KF-5-1+allicin were increased by 28.84%,18.76%and 40.87%,respectively.The total control effect of all treatments was 54.06%-67.42%,and the control effect of KF-5-1+allicin treatment was significantly higher than that of other treatments,and the highest control effect was 67.42%.(3)Field agronomic traits and disease control of three cotton varieties with different resistance were investigated with four treatments.The results showed that KF-5-1 treatment had a strong growth promoting effect on the height of cotton plant,and the maximum height was72.55 cm.The control effect of bacillus subtilis wettable powder treatment was 62.09%,followed by KF-5-1+allicin treatment,61.68%.KF-5-1+allicin treatment significantly increased cotton yield,lint yield increased 341.23 kg/hm~2,the increase rate was 21.59%.The seed cotton yield increased by 843.54 kg/hm~2,and the increase rate was 21.17%.At the same time,the number of fruit branches,bolls,lint weight and seed cotton weight of also had a slight gain effect.