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

The effectiveness of short hypobaric treatments against postharvest rots was 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 hypobaric treatment. Sweet cherries exposed to 0.50 atm for 4 h had the lowest incidence of gray mould, brown rot and total rots, while a 1 h treatment was not effective. On strawberries, the greatest reductions of gray mould and Rhizopus rot were observed on fruits treated for 4 h at 0.25 and 0.50 atm, respectively. On table grape bunches treatment with 0.25 atm applied for 24 h significantly reduced the incidence of gray mould. In experiments performed 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 diameter of the lesions were significantly reduced, in comparison with the controls. As a sub-atmospheric pressure of 0.25 atm did not affect radial growth of B. cinerea and Monilinia laxa, induced resistance was likely to be responsible for the observed reduction in decay. (C) 2001 Elsevier Science B.V. All rights reserved.