Hydrocooling Peaches after Waxing: Effects on Fungicide Residues, Decay Development and Moisture Loss1

Abstract Postharvest decay and weight loss of peaches ( Prunus persica (L.) Batsch) coated with a nonemulsified, water-insoluble blend of mineral oil, petrolatum, and paraffin (wax) containing 5000 ppm Botran and 2500 ppm benomyl was unaffected by subsequent hydrocooling. Botran residues on peaches waxed and hydrocooled under experimental conditions averaged 2.8 ppm, significantly less than those on peaches that were waxed but not hydro-cooled (4.2 ppm). Under commercial conditions, however, Botran residues were slightly less (2.1 to 2.2 ppm) but not significantly different than those on unhydrocooled fruit (2.5 ppm). Therefore weight loss and decay of peaches can be controlled if a nonemulsified wax containing adequate fungicide is applied prior to hydrocooling.