Factors affecting fruit set and fruit quality along branch units of different apricot cultivars

Understanding the differences in fruit quality within apricot tree canopies is necessary before developing strategies to reduce variation. Fruit set, fresh weight (FW) and soluble solids and dry matter concentrations (SSC, DMC) were lower, by up to 30%, 28 g, 2.4% and 2.5%, respectively, in fruit from 1-year-old long shoots and terminal spurs or from short shoots and spurs on 4-year-old wood, than on those from 2-and 3-year-old wood, for the six genotypes examined. Genotype, year and wood age affected mealiness, gel development, rubberiness and/or juiciness in fruit after cold storage. Effects of position along the shoot, fruit number and fruiting node leaf area on fruit quality were examined for one cultivar. FW, SSC and DMC were higher in fruit on distal zones of 2-year-old wood, but were lower in fruit from distal zones of 1-year-old wood. Greater fruit number per shoot before thinning decreased FW on 2-year-old wood. On 1-year-old wood, there was an interaction between fruiting node leaf area, position and fruit FW. These results will assist in devising management techniques, such as differential thinning and pruning, to reduce fruit quality variation.