Commercial biocontrol of plant diseases such as plant-parasitic nematodes (PPNs) requires formulations that are effective under field conditions. Sustainable and safe management of root-knot nematodes (RKNs) remains a significant challenge.
Probiotic bacteria represent a safe and environmentally friendly alternative for controlling PPNs in agriculture. This study evaluated the efficacy of formulated probiotic bacteria (Pseudomonas chlororaphis RO1, Bacillus subtilis RO8, and Bacillus velezensis RO9) as biological control agents in managing RKNs, Meloidogyne incognita in kiwifruit under both greenhouse and field conditions. In laboratory assays, B. velezensis RO9 exhibited the highest efficacy, achieving a 52.2% increase in second-stage juvenile nematodes (J2s) mortality compared to the control. The probiotic bacteria strains (RO1, RO8, and RO9) were formulated in two types: a humic acid-based liquid formulation and a microencapsulated form with slow-release capability. Greenhouse experiments revealed that the liquid formulation had the greatest effect on reducing the pathogenic indices of M. incognita. Specifically, RO1 and RO9 strains in humic acid-based liquid formulations were more effective than other treatments after two applications. Consequently, these two effective isolates (RO1 and RO9, liquid formulations) were selected for evaluation under field conditions. Field trials demonstrated that, following the chemical nematicide Cadusafos (Rugby®), RO1 in humic acid-based formulation was more effective than RO9 in reducing the soil population of J2s, as well as nematode eggs and juveniles in the roots. Moreover, RO9 formulation was slightly more beneficial in reducing the number of root galls and egg masses. Regarding the reproduction factor, both RO1 and RO9 liquid formulations were statistically similar to the chemical nematicide after two applications.
Overall, the results indicate that the formulated products of P. chlororaphis RO1 and B. velezensis RO9 are effective in managing RKNs both in greenhouse and field conditions.
Mirghasemi, S. N., Khodaygan, P., Taheri, A., Jamali, S., & Banihashemian, S. N. (2025). Biocontrol efficacy of formulated probiotic bacteria against Meloidogyne incognita in Kiwifruit under greenhouse and field conditions. Scientific Reports, 15(1), 1-10. https://doi.org/10.1038/s41598-025-05523-x
Source: Nature Magazine
