Foliar application of calcium reduces postharvest decay in sweet cherry fruit by various mechanisms

Sweet cherry trees were sprayed with calcium solution once a week from petal fall until two weeks prior to harvest. Fruit from calcium treated trees had higher content of soluble solids. No significant differences were observed in colour, firmness and acidity. Foliar calcium applications reduced fruit susceptibility to develop cuticular fractures. Calcium treated fruit lost more weight during storage than untreated controls. Untreated fruit with many cuticular fractures lost more weight than corresponding fruit with few fractures. In calcium treated fruit, however, no difference was observed in weight loss from fruit with many or few cuticular fractures. This indicates that the cuticular fractures in calcium treated fruit were less severe. The content of phenolic compounds was higher in calcium treated fruit compared to untreated fruit. Less cuticular fractures, less severe fractures and an increase in the content of phenolic compounds could be different mechanisms in which calcium reduced decay in sweet cherries.