Monitoring the efficiency of Streptomyces galilaeus strain KPS-C004 against root knot disease and the promotion of plant growth in the plant-parasitic nematode infested soils

Streptomyces galilaeus strain KPS-C004 obtained from the plant-parasitic nematode infested soil suppressed up to 58% of root knot disease of chili caused by Meloidogyne incognita in a greenhouse experiment. The strain promoted plant growth by increasing biomass, shoot and root length by 81%, 46% and 100%, respectively. The same trend was observed with plant nutrients, increases of nitrogen, phosphorus, potassium, calcium, magnesium and iron in chili in the treatments inoculated with spores of the strain KPS-C004 were up to 27%, 27%, 40%, 18%, 37% and 137%, respectively. The highest control efficiency of the strain was recorded when inoculated its spores in the vicinity of chili roots before nematode invasion. In addition, S. galilaeus strain KPS-C004 was capable of surviving and proliferating in the nematode infested soils throughout the entire 45 days of a cultivation period. However, reinoculation at every 15 days is recommended in order to achieve better control potential of the strain. Besides its biological control potential and plant growth-promoting attributes, the strain did not affect soil bacterial community. Altogether, its beneficial characteristics suggested that S. galilaeus strain KPS-C004 could be a potential biocontrol agent for being integrated in the root knot disease management program.