BIOCONTROL OF POSTHARVEST DISEASES OF APPLE USING BACILLUS SPP ISOLATED FROM STORED APPLES

Ninety-five bacterial isolates were recovered from 38 of 77 apples that had been stored at 1 degrees C for 6-7 months. The highest number of bacteria were recovered in nutrient,dextrose, and V8 juice broths, respectively. The bacteria were screened as biocontrol agents on cultivar Red Delicious apples primarily for control of blue mold caused by Penicillium expansum. Three bacteria effective against P. expansum were also tested against Botrytis cinerea for control of gray mold. Ten, four, and five isolates significantly reduced blue mold decay when apples were stored at 5, 10, and 20 degrees C. Two isolates tested against gray mold decay significantly reduced decay at 5 and 10 degrees C and one isolate was effective at 20 degrees C. Thirty-six isolates that had been selected for identification by the Biolog Microstation(TM) System were Gram positive and contained endospores, and 30 of these were positively identified as Bacillus spp. Further testing of 15 isolates that were effective biocontrol agents identified 7 as Bacillus subtilis on the basis of 15 microbiological tests used for determining species within the genus Bacillus.