Effects of Preharvest and Postharvest Calcium Treatments of Peaches on Decay Caused by Monilinia fructicola. William S. Conway, Research Plant Pathologist, USDA, ARS, Horticultural Crops Quality Laboratory, BARC-West, Beltsville, MD 20705. George M. Greene II, and Kenneth D. Hickey. Associate Professor, and Professor, The Pennsylvania State University, Departments of Horticulture and Plant Pathology, Fruit Research Laboratory, Biglerville 17307. Plant Dis. 71:1084-1086. Accepted for publication 12 June 1987. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1987. DOI: 10.1094/PD-71-1084.

Jerseyland peaches were treated with solutions of CaCl₂ either by 10 weekly preharvest sprays at rates of 0, 30, 60, or 90 lb / acre or pressure-infiltrated (68.95 kPa) at harvest with 0, 2, or 4% solutions of CaCl₂. Fruit from all treatments were stored at 0 C for 3 wk. After removal from storage, the peaches were inoculated with a conidial suspension of Monilinia fructicola. After 3 days at 20 C, the fruit were rated for decay severity and analyzed for calcium content. Fruit sprayed at the rate of 90 lb / acre of CaCl₂ had 70% more calcium in the flesh than untreated fruit but showed no reduction in area of decay. Fruit pressure-infiltrated with 2 or 4% solutions of CaCl₂ had two and four times as much calcium in the flesh and 40 and 60% less decay, respectively, than untreated fruit, but the treatments caused injury to the fruit surface.