Tree and orchard variability of Silver King nectarine (Prunus persica (L.) Batsch) fruit quality components

The variability of crop quality accounts for most of seasonal variation of farmers' incomes, since fruit growth and quality components may greatly change according to various environmental and within-tree factors. Canopy architecture and orchard layout are mainly responsible for fruit size, quality and its variability. A positive relationship was measured in peach between intercepted radiation and PAR and Trolox equivalent antioxidant capacity (TEAC). This study was carried out to measure within tree and orchard variability of fruit of the early ripening cv. Silver King nectarine (Prunus persica (L), Batsch) 8-years-old peach trees trained to a Y-shape and Delayed vase. Fruit were picked twice and all harvested fruit were analysed in terms of size, soluble solids content, titratable acidity, pH, firmness and TEAC. Fruit weight variability between single trees was larger than within the tree and between training systems. Fruit soluble solid content and firmness had a higher variability than fruit size and within tree variability was higher in Delayed vase trees than in Y-shaped ones. TEAC changed with fruit position within the canopy.