Postharvest Control of Botrytis cinerea on Cut Roses with Picro-cupric-ammonium Formate. P. E. Hammer, Department of Vegetable Crops, University of California, Davis 95616. J. J. Marois, Department of Plant Pathology, University of California, Davis 95616. Plant Dis. 72:347-350. Accepted for publication 5 November 1987. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/PD-72-0347.

A new copper-based fungicide, a soluble tannate complex of picro-cupric-ammonium formate (PCAF), was evaluated for postharvest control of infections of Botrytis cinerea on rose (Rosa hybrida) flowers. Dip treatments of PCAF significantly reduced disease severity on cut rose cultivars Sonia, Royalty, and Gold Rush during storage at 2.5 C and promoted poststorage fresh weight gain (an index of flower quality). Treatment with 1,000 mg/L of PCAF reduced disease severity to 3% of that on control flowers. PCAF was phytotoxic at 4,000 mg/L. Disease control (depending on the cultivar) was comparable to or greater than that achieved with 1,800 mg/L of vinclozolin. Vinclozolin formulations left visible residue on the flowers, but PCAF did not.