SAVORY ESSENTIAL OIL EFFECT ON POSTHARVEST CONTROL OF RHIZOPUS ROT ON PACKAGED PEACHES IN POLYETHYLENE FILMS

Postharvest diseases limit the storage period and marketing life of peaches. Rhizopus rot, caused by Rhizopus stolonifer (Ehrenb. Fr) Vuill., is one of the most destructive postharvest diseases of stone fruits. The aim of this investigation was to evaluate the antifungal effects of the herbal essential oil of savory (Satureja hortensis) against Rhizopus stolonifer, causal agent of Rhizopus rot on peach. In in vitro trials, the activity of savory oil was tested against pathogen mycelium growth. Essential oil was added to the medium (ranging from 120 to 360 μl/L), or to a filter paper (ranging from 1, 3, 6, 12, 24 and 48 μl/L) inserted on the lid of petri dish to assay its volatility. In in vivo experiments, four concentrations of Savory oil (0, 120, 240 and 360 µl/L) were tested by dipping and seven doses (0, 50, 100, 200, 400, 800 and 1600 µl/L) were applied as vapour phase on ‘J.H. Hale’ peaches artificially inoculated with the pathogen (10⁶ conidia ml/L). Fruit were stored at 25 or 1°C for 20 and 45 days respectively. In in vitro results the concentrations of 360 μl/L used in medium and that of 24 μl/L used as volatile showed the highest activity against Rhizopus growth. In in vivo trials, the most effective concentration of essential oil was 360 μl/L used by dipping and 24 μl/L used as biofumigant. More investigation is in progress to evaluate the practical application of savory oil.