Acinetobacter calcoaceticus SJ19 and Bacillus safensis SJ4, two Algerian rhizobacteria protecting tomato plants against Botrytis cinerea and promoting their growth

Abstract Background Botrytis cinerea , the causal agent of grey mould, is a polyphagous fungus that infects wide range plants, including tomato. In many countries, Algeria, management mould challenging problem, even with chemical control. This necessitates search for other strategies. The objective this study was to evaluate biocontrol potential two rhizospheric bacterial isolates protection tomato against B. . Results On consistently provided high levels (on average 72.1% SJ19 and 52.3% SJ4). Their applications as 1:1 mixture reinforced their effect (87.8% protection), indicating compatibility use consortium. vitro, significantly inhibited mycelial growth strains, both through direct confrontation in dual-culture assays (12–69% inhibition) production volatile compounds (36–46% inhibition). isolates, applied seed treatment drench on seedlings, also showed strong growth-promoting effects tomatoes. They substantially increased length fresh weight shoots roots, well stem diameter, leaf number chlorophyll content, compared untreated plants. Conclusion bacteria tested biostimulants biofungicides mould.