Prediction of bitter pit with calcium content of apple fruit

Abstract

Calcium concentrations in apples were found to be correlated with bitter pit susceptibility, a low calcium concentration being synonymous with high pit susceptibility. The concentration of calcium in the fruit 3 weeks before harvest was as reliable a guide for predicting pit as the concentration in the fruit at harvest. However, between districts and varieties, and in different seasons, there were marked differences in the amount of calcium above which fruit were unlikely to develop pit. Although calcium concentration was most closely correlated with pit, potassium and, to a less extent, magnesium concentration were also positively correlated with the disorder. The ratio of K/Ca was very highly correlated with pit.