THIS STUDY aimed to evaluate the efficacy of applying spores and chitinase enzyme of Streptomyces parvulus strain 10d in biological control of damping-off disease caused by Rhizoctonia solani in green beans (Phaseulus vulgaris) and compare it with Rhizolex fungicide application. Five seeds of green bean were sown in plastic pots, filled with either sterilized or non-sterilized soils, infested with R. solani inoculum (5g/kg soil). Pots were kept in the greenhouse for 45 days from sowing. Pre-emergence damping-off was recorded 15 day from planting and post-emergence damping-off and survival rate were recorded 30 days from planting. Plants growth characteristics were recorded 45 days of sowing.
Results showed that Rhizolex treatment had the best survival rate and lowest root–rot severity (79 and 25%), followed by crude enzyme treatment (76 and 25%), then spores' treatment (75 and 27%, respectively), in infested and non-sterilized soils.
For plant growth characteristics, in infested and non-sterilized soil, spores' treatment had the best effect on plant height (41.5cm), followed by crude enzyme (39.5cm) and Rhizolex treatments (34.6cm). Numbers of leaves/plant were the highest in Rhizolex (17), followed by spores (15) and enzyme treatments (14). Numbers of pods/plant were 14 in Rhizolex treatment and 11 in crude enzyme and spores' treatments. The highest dry weight was recorded in spores' treatment followed by Rhizolex treatment (10 and 7 g/plant, respectively). 
Conclusions: results suggest that using chitinolytic Streptomyces strain 10d for the biological control of R. salani and damping-off disease of green bean plants can be an attractive alternative for pesticides in organic agriculture.