Abstract:
Faba bean (Vicia fabae L.) is one of the most important pulse crops in Ethiopia due to its high
nutritive values and significant contribution to soil fertility by fixing atmospheric nitrogen.
Production of faba bean in Ethiopia is low from estimated value which is due to abiotic and biotic
factors. From biotic factors Checholate spot is the major and most distractive disease in faba bean
growing area. In Ethiopia there are different researches that have been done on growth promoting
and controlling different types of Faba bean diseases by using of Plant Ggrowth Promoting
Rhizobacteria (PGPR). However, most approaches for biocontrol of plant diseases have been using
single biocontrol agents as antagonists against a single pathogen. This may partially account for the
reported inconsistent performance by biocontrol preparation. The aim of this study was in vitro
evaluation of bacterial consortium for growth promoting and suppressing of chocolate spot (Botrytis
fabae) on Faba bean. The bacteria were isolated and characterize following the procedures in Bergy’s
manual of systematic bacteriology. The isolates were screened for plant growth promoting
characteristics in single and consortium, and the antagonistic activities of all isolated bacteria were
studied on B. fabae by dual culture technique. A total of five bacteria namely Serratia spp.,
Microccus spp., Bacillus spp., Peudomonas spp. and Entrobacter spp. were isolated and all of them
were compatible to each other. All of them produced IAA, ammonia and also solubilized
phosphorous in single inoculum as well as in consortia. Among the antagonistic effects of single
bacterial treatment against Botryits fabae, the maximum inhibition zone was created by
Pesudomonas spp. (73%). The result of this study showed that while the number of bacterial
treatment increases the percent of inhibition of Botrytis fabae was also increased. The percentage of
inhibition formed by T25 which contains five bacterial inoculum was the highest from all treatments
(87.8%). From the experimental works of this study, it can be concluded that using bacterial
consortium is the best way to control Botryits fabae than using single bacterium and the number of
bacteria as consortium increase the amount of IAA and ammonia production also increase.
Keyword : Bacterial consortia, Biocontrol, Botrytisfabae, Faba bean,
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