ABSTRACT

Biological control has emerged as one of the promising alternatives because it reduces the risks of chemicals on the environment and health. The aim of this study was to isolate Bacillus from carrot that have antagonistic activity and hence a biocontrol potential. Bacterial isolates were isolated from carrot using the pour plate method, and were then morphologically and biochemically characterized. The isolates were identified according to standard methods as Bacillus species. Pseudomonas aeruginosa and Micrococcus species with 58.3%, 16.7% and 16.7% occurrence respectively. Biocontrol potential ofthe Bacillus isolates were tested by invitro, root rot symptoms were examined visually daily following inoculation. Pre-treatment ofthe carrot root samples with the Bacillus isolates for disease control reduced disease severity significantly with a higher control efficacy than the samples left uninoculated. No rot symptoms were produced on carrot roots inoculated with the various Bacillus cell suspensions. However, brownish discoloration or rot symptoms were produced on the carrot roots that were uninoculated with any ofthe isolates. The results ofthis study indicate that Bacillus organisms have great potential as an efficient biocontrol agent for managing carrot root rot and also carrot root should not be washed before storage, but can only be washed before use so as not to wash offthe biocontrol-microflora,there-by reducing the shelf-life.