MONILINIA AND RHIZOPUS DECAY CONTROL DURING CONTROLLED RIPENING OF FREESTONE PEACHES FOR CANNING

ABSTRACT— Decay was controlled when freestone peach fruit, harvested at various stages of maturity ranging from green to straw-color, were dipped in 50% 2,6-dichloro-4-nitroaniline (DCNA) at 1–1/2 and 4 lb/100 gal water and ripened for 5–17 days at 20°C and 90% R.H. Treated fruit had less than 10% decay while untreated fruit developed as much as 61% decay during this period. Regardless of treatment, straw-blush and full-blush fruit held for only 3 days did not develop decay. The most commonly occurring fungus pathogens, Monilinia fructicola and Rhizopus stolonifer, were controlled with these treatments. Postharvest DCNA plus captan dip treatments gave more effective decay control than from preharvest field sprays. Concentrations of DCNA or DCNA plus captan required for Monilinia decay control, suggested by preliminary laboratory tests on fruit, were verified by these commercial-size experiments.