THE EFFECT OF DIFFERENT CALCIUM LEVELS ON CATION CONCENTRATION IN LEAVES AND FRUIT OF APPLE TREES

Abstract

Increasing the calcium levels from 32 to 256 mg/L in a Long Ashton nutrient solution increased the Ca but decreased the Mg content in leaves and fruit of three cultivars of apple (Malus domestica Borkh.) grown in solution. Simultaneously, the levels of K were reduced and the levels of Mn were increased.in the leaves but levels of K were not affected in the fruit. The cation levels in leaves differed between cultivars and years of testing. Golden Delicious leaves had consistently higher levels of Ca than Delicious and McIntosh, and higher K and Mn, but not Mg than McIntosh. The levels of Mg and Mn in Golden Delicious leaves were significantly lower than in Delicious but K levels were higher.Key words: Calcium, cations, apple, hydroponics