Chemical Control of Fungi Causing Decay of Fresh Prunes During Storage. Themis J. Michailides, Former Graduate Research Assistant, Department of Plant Pathology, University of California, Davis 95616. J. M. Ogawa, and P. L. Sholberg. Professor, Former Graduate Research Assistant, Department of Plant Pathology, University of California, Davis 95616. Plant Dis. 71:14-17. Accepted for publication 29 July 1986. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0014.

Fresh prunes can be held in cold storage with no internal breakdown for 2–3 wk. Amount of decay during storage and reduction of molds by chemical treatment were directly related to methods of harvest and temperature of incubation. Molds that caused decay were species of Cladosporium, Monilinia, Rhizopus, Mucor, Penicillium, Botrytis, Alternaria, and Aspergillus. Untreated prunes held at 4 C developed mold on the seventh day, and by the 20th day, 14, 39, and 94% of the prunes from Tulare, Yuba City (mechanically harvested), and Healdsburg (hand-harvested from the ground), respectively, had decayed. Prunes treated with chlorine (400 mg/L of water), etaconazole (450 mg/L of water), and potassium sorbate (20,000 mg/L of water) showed no mold until the 10th day of storage at 4 C and had significantly less decay on the 20th day. Prunes treated with the above chemicals and held at 20 or 28 C for 4 days showed lower amounts of decay than the untreated prunes; however, the effect of chemical treatments on prunes stored at 28 C was not consistent. Prunes mechanically harvested from Tulare and Yuba City showed significantly less decay than prunes hand-harvested from Healdsburg. There were no differences in the amount of decay between washed and unwashed prunes incubated at 4, 20, and 28 C.