枯草芽孢杆菌LF17与甲基硫菌灵协同防治苹果树腐烂病的效果研究

通过室内测定枯草芽孢杆菌LF17与3种化学药剂对苹果树腐烂病菌(Valsa mali)的毒力,而后将菌株LF17的菌悬液与化学药剂进行复配,探讨复配剂对苹果树腐烂病菌的室内毒力及其田间防治效果。结果表明:枯草芽孢杆菌LF17与甲基硫菌灵生物相容性最好;LF17的菌悬液与甲基硫菌灵复配剂(浓度为1.36×10⁷ cfu/mL+1.0271μg/mL,按体积比5∶5配制)对苹果树腐烂病菌的抑菌率为81.36%、毒性比率为1.66、表现为增效作用,离体枝条的防治效果为74.05%,显著高于2个单剂的防治效果,且复配剂中甲基硫菌灵的使用量减少约60%。

Synergistic effect of antagonistic bacteria LF17 and thiophanate-methyl against apple Valsa canker

Toxicities of 3 fungicides and Bacillus subtilis LF17 against Valsa mali were tested in this study. The mixture of the fungicide with the strongest toxicity and B. subtilis LF17 was detected for its laboratory toxicity and control effect in the fields against apple Valsa canker. The results showed that the thiophanate-methyl was compatible with strain B. subtilis LF17. By combining thiophanate-methyl(1.0271 μg/mL) with B. subtilis LF17(1.36×10⁷ cfu/mL) fermentation broth at the volume ratio of 5∶5,the inhibition ratio and the toxicity ratio were 81.36% and 1.66. The control efficacy of compound biopesticide was 74.05% against apple Valsa canker in the field, which was better than that when each of them used alone. Meanwhile, the amount of thiophanate-methyl was reduced by 66.7% compared to that when used alone.