Assessment of disease susceptibility and fruit quality

The susceptibility to diseases is not considered as a key-criterion in peach breeding programs. Even if the turn-over of peach cultivars is important, suitability for organic and low-input systems remains unknown for most of the cultivars. A first program has been carried out from 2001 to 2008 to assess peach leaf curl, powdery mildew and aphid susceptibilities of 18 cultivars in an experimental station. Fruit quality was also assessed. A high variability in leaf curl (Taphrina deformans) and powdery mildew (Sphaerotheca pannosa var persicae) susceptibilities and fruit quality was observed among the cultivars. Reine des Vergers and Belle de Montélimar were identified as relevant cultivars for specific markets, because of low susceptibilities to diseases and high fruit quality. In 2009, they have been included in a second assessment program among 10 other cultivars, which is still going on. The variability of peach leaf curl susceptibility between cultivars was strongly influenced by the disease pressure. In 2011, we identified different levels of tree recovery among the cultivars after severe damages caused by peach leaf curl and Monilinia spp