Blue mold (Penicillium expansum) and gray mold (Botrytis cinerea) cause significant post-harvest losses of apple fruit. As a control alternative, the effects of fumigation with acetic acid, acetaldehyde, benzaldehyde, d-limonene, thymol and methyl jasmonate, at 8 and 15 µL/L of air, on the germination of spores and the incidence and severity of blue and gray mold in 'Fuji' apples were evaluated. The germination of spores was evaluated in excavated slides arranged onto plastic boxes, where the fumigant agent acted for 60 min. With optical microscopy, it was observed after 24 h that acetic acid at 8 µL/L completely inhibited spore germination of P. expansum, while limonene, thymol, benzaldehyde and methyl jasmonate partially reduced it. Only acetic acid and benzaldehyde showed an inhibitory effect on B. cinerea. In in vivo tests, fumigation was conducted in plastic boxes containing four previously inoculated fruits per plot. Acetic acid reduced the incidence of blue mold and gray mold by 44% and 100%, respectively, at 8 µL/L of air. However, it caused phytotoxicity on fruits, indicating a potential use for reduction of inoculum of Botrytis and Penicillium in the disinfestation of chambers.
Botrytis cinerea; Penicillium expansum; acetic acid; fumigation; volatile compounds
