Powder Formulation Survey of Strain Bacillus subtilis M36 for Control of Bean Root Rot, Caused by Fusarium solani f. sp. Phaseoli

In the present survey 194 gram positive bacteria isolated from the rhizosphere of bean from Markazi province and also 41 isolates from the collection of Research Center of Biological Control at Tehran Universitiy were evaluated on the basis of inhibitionry zone of fungal growth. Finally eight more appropriate strains of B. subtilis were selected for greenhouse trials. Results indicated that antagonistic bacterium B. s M36, isolated from the rhizosphere of bean fields of Markazi province exhibited the greatest effect on reducing the Fusarium root rot bean. In greenhouse trials, after six weeks, between nine formulations of strain B. s M36, the one obtained from M1 culture medium with Arabic Gum as the sticker with 68.42% of control, depicts the greatest effect on reducing Fusarium root rot was more effective than two fungicides Rovral-TS and Trichomix-HV with 56.14% and 54.38% of inhibition respectively. The results indicated that the population of B. s M36 grown from in powder formulations decreased during the storage at 4 and 25°C over a 150-day period. In addition, formulation of strain B. s M36 stored at 4°C presented a longer shelf life than those stored at 25°C. Long-term stability of formulation (M1-AG) of strain B. s M36 was the most appropriate. A study of the media on population of the effective strain, exhibited that M1 medium was the most effective, in this study.