Combining Pantoea agglomerans (CPA-2) and curing treatments to control established infections of Penicillium digitatum on lemons

The effectiveness of the strain CPA-2 of Pantoea agglomerans alone or in combination with a curing treatment at 33degreesC for 65 h to control green mold was evaluated on lemons stored at ambient temperature and in cold storage. An application of P. agglomerans at 2 X 10(8) CFU/ml effectively reduced green mold incidence on recently inoculated lemons stored at temperatures from 5 to 25degreesC. Moreover, a 30-s immersion of lemons in a P. agglomerans suspension at 2 X 10(8) CFU/ml significantly reduced green mold incidence, even when delayed up to 15 h after inoculation with Penicillium digitatum at either 20degreesC or while in cold storage. However, it failed to control established infections of P. digitatum of more than 24 It. Curing P. agglomerans-treated lemons at 33degreesC for 65 h completely controlled 24-h-old infections on artificially inoculated lemons stored at 20degreesC for 14 days and on naturally infected lemons stored at 10degreesC for 3 weeks plus 7 additional days at 20degreesC. When applied before curing, population growth of P. agglomerans in wounds was similar to that within wounds of control fruits at 20degreesC. In contrast, when it was applied immediately after curing treatment, P. agglomerans populations within wounds did not increase.