Synergistic effects of Bacillus velezensisSDTB038 and phenamacril on Fusarium crown and root rot of tomato

Abstract

AbstractFusarium crown and root rot (FCRR) is a damaging ailment that can affect tomato production. It is caused by Fusarium oxysporum f. sp. radicis‐lycopersici (FORL). The use of biological agents, in conjunction with fungicides, has become a practical strategy for combating fungal diseases in crops. Lipopeptide extracts from a potential biocontrol strain of Bacillus velezensis (SDTB038) exhibited an inhibitory effect on the mycelial growth of FORL; the EC50 value was 59.95 mg/L, and at a concentration of 256 mg/L the inhibition rate reached 97.4%. The SDTB038 strain produces metabolites such as protease and siderophores. Additionally, it is capable of forming a biofilm and swimming. Phenamacril, an antifungal agent, also displayed an inhibitory effect on FORL, demonstrating an EC50 value of 1.074 mg/L. The control effects of the combination of Bacillus velezensis SDTB038 and phenamacril against FORL on tomato plants were also studied in the greenhouse. The combination of phenamacril and 108 CFU/mL SDTB038 fermentation broth exhibited a strong synergistic control effect on FORL, of up to 84.0%. The combination also led to a 35.6% increase in tomato yield compared to the control. These results demonstrate that SDTB038 possesses antifungal activity. Moreover, when combined with phenamacril, it exhibits a strong synergistic effect against FORL. This solution proves to be an effective means of controlling FCRR in tomato plants.