Biological Control of Tomato Root Rot Disease by Indigenous Rhizobacteria in Greenhouse Setting

Rhizobacteria are essential for plant health by offering natural antagonism to soil-borne fungi. Rhizobacteria are regarded as an alternative to chemical agents for the integrated control of plant diseases and for enhancing yield in an ecologically sustainable way. Nonetheless, there is a limited comprehension of the precise processes via which rhizobacteria suppress these diseases and the variety of rhizobacterial species implicated.

Through experiments conducted in 2022–2024, the efficiency of 12 rhizobacterial isolates of Alloiococcus otitis BRE6, Aneurinibacillus thermoaerophilus SDV1, Aeribacillus pallidus ECC4, A. thermoaerophilus ECL1, Bacillus megaterium SKE2, Staphylococcus lentus BZD2, Enterobacter cloacae complex BZD3, B. megaterium TNK1, Leclercia adecarboxylata DKS3, B. halotolerans DMC8, B. subtilis NAS1 and Paenibacillus polymyxa TRS4, in controlling soilborne pathogenic fungi of Rhizoctonia solani, Macrophomina phaseolina and Pythium aphanidermatum, the causal agents of tomato root rot disease was evaluated under greenhouse conditions and plant growth parameters were evaluated.

The results indicated that the combination treatment of 12 rhizobacterial isolates (COR12) achieved the highest germination rate of tomato seeds in the presence of pathogenic fungi, reaching 100% and the lowest rate of disease incidence and severity, reached 5% and 1%, respectively, compared to the positive control treatment, which reached 82% and 53%, respectively. Representing control disease value of 98% compared to the single bacteria treatments. The COR12 treatment achieved a significant increase in the growth parameters represented by plant height and fresh and dry weight of the shoot and root system in the presence of pathogenic fungi compared to the individual bacterial treatments.