Effect of short hypobaric treatments on postharvest rots of sweet cherries, strawberries and table grapes

The effectiveness of short hypobaric treatments against postharvest rots wa s investigated by exposing sweet cherries, strawberries and table grapes to sub-atmospheric pressures (0.25, 0.50, and 0.75 atm) for different times ( from 1 to 24 h). Postharvest rots of sweet cherries and strawberries arose from natural infections, whereas small table grape bunches and artificially wounded single berries were inoculated with Botrytis cinerea after hypobar ic treatment. Sweet cherries exposed to 0.50 atm for 4 h had the lowest inc idence of gray mould, brown rot and total rots, while a 1 h treatment was n ot effective. On strawberries, the greatest reductions of gray mould and Rh izopus rot were observed on fruits treated for 4 h at 0.25 and 0.50 atm, re spectively. On table grape bunches treatment with 0.25 atm applied for 24 h significantly reduced the incidence of gray mould. In experiments performe d with artificially wounded single table grape berries exposed to 0.50 atm for 24 h and then inoculated, the percentage of infected fruits and the dia meter of the lesions were significantly reduced, in comparison with the con trols. As a sub-atmospheric pressure of 0.25 atm did not affect radial grow th of B. cinerea and Monilinia laxa, induced resistance was likely to be re sponsible for the observed reduction in decay. (C) 2001 Elsevier Science B. V. All rights reserved.