Strategies for improving fruit quality in European plum

Fruit size, flesh firmness, color of the fruit skin and the flesh, adherence of the fruit flesh to the stone, caverns within the fruit flesh, content of sugars, organic acids and aroma components are important quality traits in European plum. In order to improve the fruit quality of European plum the main influencing factors on fruit quality have to be known. Fruits of different European plum cultivars and breeding clones originating from the Hohenheim and Weihenstephan plum breeding program were harvested and analyzed concerning 20 different fruit characters amongst them the soluble solid content, the organic acid content, fruit mass, fruit length and width. The influence of the locations, the harvesting time and the crop load on fruit quality was compared. Both picking time, crop load and the genetic determination were shown to be important influencing factors on fruit quality. In many cultivars, fruits harvested from PPV infected trees were of lower fruit quality than fruits grown on healthy trees. Thus, breeding can be regarded to hold the key position in enhancing fruit quality in Prunus domestica. However, crop load and harvesting time have to be optimized as well in order to exhaust the full genetic potential of a respective genotype.