Bitter pit potential of apples

The use of non-destructive techniques to determine bitter pit potential that were evaluated during the past two seasons viz., chlorophyll fluorescence and near infrared spectroscopy could not differentiate 100% between apples with a potential to develop bitter pit and those that did not develop the disorder.  However, the techniques could possibly be used to detect maturity at harvest, which could then be used to separate under mature fruit from optimum maturity fruit which could reduce the bitter pit potential.  Ca uptake was monitored to determine the efficacy of applications during different stages of fruit development. Differences were found in Ca concentration and bitter pit development, but in order to predict bitter pit potential, one has to look at variation between Ca content of individual fruit within a sample and to determine the effect of number of applications and timing on within tree variability.  Also the effect of pruning on dry mass allocation and Ca allocation was determined.