Rhlzosphere colonizing bacteria and fungi were counted and isolated from
samples of six crops grown in reclaimed fields lit Manout districts. A total of 69
bacterial and 22 fungal Isolates in addition to four known bioagents were tested, in
vitro, for their antagonistic effect against the agents of wilt and root rot of pepper
namely Fusarium Oltysporom, Pythium aphanidarmatum and Rhizoctonla solani.
Twenty three isolates showed moderate to stron~1 inhibition or hyperparasitism on
mycelium of at least one of these pathogens The biocontrol ability of these
antagonists Isolates was evaluated using an in vivo assay. Accordingly, six isolates
were selected and used for soil treatment to control root rot and will of pepper in pot
experiments. The most effective isolates were Pseudomonas nuorescens (SA 1),
lollowed by T. harzianum (Th1) and reduced root rol or wilt Incidence by not less than
75%. Significant mcrease in fresh and dry weight of pepper plants treated by P.
fluorescens or T. harzianum were obtained In pathogens free solts, Treatment of
pepper transplants by both BA-1 and Th-5 isolates, before transplantinq in Ihe field,
significantly (educed incidence of root rot and will of pepper, however, isolate Th5 had
the dual effecl of disease sl.Ippression as well as growth and yield Increase.