THE EFFECT OF NUTRIENT CONTENT ON QUALITY AND STORAGE LOSSES OF ´BRAEBURN´ APPLES

In the 1999 and 2000 growing seasons we studied the relationship between “Braeburn browning disorder” (BBD), mineral content, fruit quality and storage losses on ‘Braeburn’ apples (Malus x domestica Borkh.). At several locations ‘Braeburn’ apples were picked at the optimal stage of maturity. The effects of harvest date, crop load and minerals on fruit quality and storage losses were evaluated. The main factor contributing to storage losses of ‘Braeburn’ was a high P level in fruits. Firmness at harvest was the most important variable for firmness after storage and shelf-life. Firmness immediately after controlled atmosphere (CA) storage was highly correlated to firmness at harvest and Ca (R² = 99.5%), whereas firmness on the market was related to firmness at harvest and to the Ca, Mg, K and P concentration in fruits (R² = 99.2%). To prevent firmness losses during shelf life, the optimal Ca content in ‘Braeburn’ fruits should be above 5.0 mg 100 g-1 fresh weight.