Five fungal isolates, i.e. Pythium sp., Sclerotium rolfsii, Macrophomina phaseolina, Rhizoctonia solani and Fusarium solani, were evaluated for their pathogenicity to pea plants. Pathogenicity test proved that R. solani followed by S. rolfsii and F. solani were the most virulent pathogens which caused the highest incidence of root-rot and damping-off of pea plants. Antagonistic effect of certain effective bioagent, isolated from pea rhizosphere and identified as Brevibacillus brevis revealed the presence of clear antagonistic action on root-rot pathogens. The highest mean inhibition values were 94.2 and 91.3% against F. solani and R. solani, respectively.
Three dry based bioformulations, i.e. cellulose-clay, talc-glucose and talc-yeast, in which B. brevis incorporated, were used. The viability of the dry bioformulations over 6 months at room temperature was assessed, and this indicated the long shelf life of the three formulas which ranged from 68.3 to 52.4% of viable cells after 180 days of storage. The potentiality of these formulations and free spore suspension of the bioagent in controlling root-rot incidence, under greenhouse and field conditions, were evaluated. Data indicated that root-rot severity reached the highest values when mixture of pathogenic fungi was applied. All tested formulations significantly reduced pre and post emergence damping-off of seedlings and root-rot incidence. Dry bioformulations of B. brevis, especially cellulose-clay, proved to be more effective than its free spore suspension in soil infested with pathogens. The efficacy of all tested dry bioformulations in controlling disease was reflected on the plant growth causing significant increase in all growth parameters measured. These data indicate that dry bioformulations of B. brevis can be used as a promising tool for seed treatment as biocontrol agents for controlling damping-off and root-rot of pea plant.