There were significant differences among the bacterial strains (P < 0.05) for reducing the fungal growth in vitro
condition (Table 1). According to the (Table 1), among of the 182 bacterial isolates, 7 isolates exhibited a more
than 30% inhibition of mycelia growth of S. sclerotiorum by non-volatile inhibitors. The maximum inhibition achieved
by isolates PE, SH and AE (>36%). Furthermore, volatile metabolites of three isolates ME, LE and AE inhibited the
mycelial growth of S. sclerotiorum considerably. Growth inhibition of S. sclerotiorum by PE, SH and AE was
significantly greater than others (Figure1 & Table 1), while strain FE2 had less effect on the growth of the pathogen
(Table 1). In current study we isolated and screened the rhizobacteria from cucumber plants with antagonistic
activity against S,sclerotiurom the causal agent of cucumber stem rot. The approach provided an opportunity to
select effective biocontrol strains capable of antagonizing soil-borne pathogens in thesame environment where
they will be used commercially