Reduction of gray mold development in table grapes by preharvest sprays with ethanol and calcium chloride.

Preharvest applications of a 16% ethanol (EtOH) solution, containing 1 % of calcium chloride (CaCl2), reduced gray mold development in ‘Chasselas’ table grapes picked at a late harvest date, the losses due to rotten clusters dropped from 15% in controls to 5% in grapes treated with EtOH+CaCl2. Then over a 6-week cold storage, the losses due to gray mold rots were reduced by 50% when storing EtOH+CaCl2 treated clusters, compared to untreated controls. Preliminary experiments had shown that a 2% EtOH solution was already inducing significant drop of gray mold growth. A range of concentrations up to 50% ethanol had been tested in preliminary trials without observing damages to the vines and clusters. The treatments did not induce significant changes to the fruit quality assessed by sensory analyses on healthy berries