A Sensitive Method for Measuring Changes in Calcium Concentration in ‘McIntosh’ Apples Demonstrated in Determining Effects of Foliar Calcium Sprays1

Abstract

Abstract Three different methods of sampling flesh of apple ( Malus domestica Borkh.) for Ca analysis produced different results due to uneven Ca distribution in the fruit. A sensitive, reproducible method of sampling and analyzing the outer cortex of the calyx half of fruits indicated that Ca concentration in different parts of the fruit changed significantly after harvest, decreasing in the core and increasing in the outer cortical tissues. Massive applications of CaCl 2 to trees shortly before harvest increased flesh Ca concentrations and red coloration of the fruit, decreased flesh softening during storage and senescent breakdown after storage, but caused significant injury to the fruit.