The efficiency of formulations containing chitosan and the adjuvants glycerol, sorbitol, sorbitan oleate, Tween 80 and magnesium stearate was evaluated for the control of blue mold in apple fruits. Apples of cv. Fuji were disinfested, wounded and immersed for 3 minutes in the suspensions. After drying for 2 h, fruits were inoculated with Penicillium expansum and stored under high relative humidity, at 25+1 °C. The disease severity was evaluated periodically and the blue mold incidence was measured at 16 days after inoculation. The blue mold incidence in fruits immersed in chitosan was reduced by around 40%. On average, a reduction of 53% and 72% in severity was observed on fruits immersed in chitosan at 0.25% and 0.5%, respectively, compared to the control. Among the formulations, the one containing chitosan 0.5%, magnesium stearate 0.3% and Tween 80 0.1% was the most promising for controlling blue mold. It reduced the decay incidence in 75% and the disease severity in 97,7%. The addition of adjuvants sorbitol and sorbitan oleate to the chitosan suspension has not contributed significantly to increase the levels of decay control.
Malus domestica; Penicillium expansum; coatings; post-harvest
