There is a growing need to reduce the reliance on chemical pesticides by developing microbial products that can be widely applied with reproducible efficacy to treat multiple plant diseases. The objective of our study was to screen candidate microbial...
There is a growing need to reduce the reliance on chemical pesticides by developing microbial products that can be widely applied with reproducible efficacy to treat multiple plant diseases. The objective of our study was to screen candidate microbial antagonists for different plant diseases and identify widely effective candidates to develop a broad-spectrum biocontrol formulation. We assessed seven candidate strains against five representative pathosystems: tomato Fusarium wilt, pepper damping-off, pepper Phytophthora seedling blight, pepper anthracnose, and rice sheath blight. In tomato Fusarium wilt, strain H1 displayed the strongest suppression with the disease index (DI) ≤ 1. H2 and R7 provided moderate control (DI 1.2 and 3, respectively), while H3, H4, R5, and R6 were ineffective against tomato Fusarium wilt. In pepper damping-off, treatment effects in early infection stages were highly variable as H1, R5, and R6 exhibited low mean DI (≤1) that did not achieve statistical significance. Treatment effects varied widely in pepper seedling blight, with R5 showing reduced disease tendency. H1, H2, and R7 completely prevented the symptoms of pepper anthracnose, while H1, R5, and R7 markedly reduced rice sheath blight severity. Overall, H1 emerged as the most promising broad-spectrum candidate. Further research should focus on application optimization, mechanistic validation (rhizosphere colonization and induced resistance), and robustness verification across diverse pathogen isolates and growth conditions.