Scilate Apple Mineral Distribution and Prediction of Bitter Pit

Calcium deficiency in apple fruit has been identified as a primary cause of bitter pit in apples, however some apples are not as susceptible as others. The apple cultivar ‘Scilate’ has been identified as less susceptible to bitter pit, but it is not known whether high calcium concentrations are what contribute this resistance. Because scilate is a more recent variety, little research has been done to observe the effects of crop load, fruit size, and vegetative growth on calcium concentrations. Cortical plug and peel samples from apples selected from heavy cropped trees grown on EMLA 26, and light cropped trees, grown as stock trees for scion wood, on EMLA 106 were analyzed for macro and micronutrient concentrations. We found that fruit from EMLA 26 had a higher calcium concentration, and a lower Mg:Ca ratio compared to fruit from EMLA 106. It could not be determined if high calcium caused resistance to bitter pit in scilate, however, apples from scionwood trees should not be commercially harvested due to lower calcium concentrations correlative with higher incidence of bitter pit.