Analysis of the Control Effect of Bacillus amyloliquefaciens C4 Wettable Powder on Potato Bacterial Wilt Caused by Ralstonia solanacearum

Potatoes are one of the most important food crops worldwide, but their growth and development are often seriously threatened by potato bacterial wilt. The wettable powder produced by Bacillus amyloliquefaciens C4 under optimized fermentation conditions effectively inhibits potato bacterial wilt. In this study, lipopeptide antibiotics were identified via PCR and MALDI-TOF-MS, and their antibacterial activity was determined. The optimal formulation of C4 wettable powder was optimized via a single-factor experiment combined with a response surface. The effect of C4 wettable powder on potato bacterial wilt was evaluated. In the antibacterial activity test, surfactin showed better inhibition ability. After determining the optimal liquid fermentation conditions and wettable powder formula, the surfactin activity increased to 540.15 mg/L, and the C4 wettable powder activity reached 69.67 × 108 cfu/g. The results of the pot experiment showed that the best cost-effectiveness was achieved under 500 times dilution and spraying, with a control effect of 79.05 ± 24.79%. The physiological and biochemical results showed that C4 wettable powder could induce rapid defense enzyme responses in leaves and enhance plant resistance to pathogenic bacteria. The results showed that C4 wettable powder effectively controlled potato bacterial wilt, and its application method was determined.