Effect of Calcium Application on Fruit Quality of Apples Produced in Warm Regions

Abstract

The effects of calcium (Ca) application on fruit firmness, ethylene concentration and Ca uptake of ‘Jonagold’ apple [Malus sylvestris (L.) Mill. var.domestica (Borkh.) Mansf.] were investigated. A 2.5 g⋅L^-1Ca (1.425g⋅L^-1calcium sulphate dihydrate, 0.675g⋅L^-1calcium chloride and 0.4 g⋅L^-1others) solution was applied to whole tree at 4 days intervals from 20 to 60 days after full bloom (DAFB) . Ca treatment decreased internal ethylene concentration compared to the untreated control. Bound Ca concentration in the cell wall of Ca-treated fruit was higher than that of untreated control. Although the firmness of Ca-treated fruit showed higher value than that of the control before coloring, they had no significant difference after coloring. These results demonstrate that Ca treatment at 20-60 DAFB may prevent the increase of ethylene production, resulting in the delay of fruit senescence, prior to coloring, which is often observed in warm regions.