Control efficacy of Streptomyces roseoflavus tablets on cucumber root-knot nematode and its effect on soil microorganisms

Streptomyces roseoflavus Men-myco-93-63 is a biological agent isolated from potato scab disease declined soil and has evident antagonistic action against many plant pathogens, including root-knot nematode. In order to evaluate the application prospects of Men-myco-93-63 tablets in controlling root-knot nematode, greenhouse pot experiment and dilution-plate method were conducted to determine the control efficacy of the tablets on cucumber root-knot nematode and its effect on soil microorganisms. The results showed that the control efficacy were 51.85% and 55.56% after treatment on cucumber by 1.0 g/plant and 1.5 g/plant, respectively, while that of the control agent- Paecilomyces lilacinus and solid fermentation of Men-myco-93-63 were 54.17% and 50.00%, respectively. Men-myco-93-63 tablets had marked effect on soil microorganisms after 60 days, the number of bacteria and actinomyces increased by 225.45% and 75.45% respectively, and the number of fungi reduced by 66.43% after treatment on cucumber by 1.0 g/plant. The total number of the 3 kinds of soil microorganisms increased by 195.35%, suggesting the tablets could significantly improve the structure of soil microorganisms.