Peach-nectarine: comparison of the sensitivity to pests and diseases of new cultivars - first results of an evaluation network led in France since 2012

The societal expectations in term of reduction of the use of inputs in agriculture, and more particularly plant protection products, interdiction of some commercial specialties (that lead, in some cases, to technical impasses) and development of more restrictive specifications from wholesalers, make the management of pests and diseases particularly complex. A possible solution is to identify more resilient cultivars. The breeding programs in France are very intense, considering the number of cultivars proposed to the assessment network each year. The assessments are usually based on observations related to tree management (shape, vigor, etc.), agronomic performance (yield, fruit size), the presentation of the fruit (color) and fruit organoleptic quality. n the frame of the 'cultivars and rootstocks assessment national chart', specific orchards have been planted to evaluate the sensitivity of around 30 cultivars to various pests and diseases. These orchards permit collections of complementary information on new cultivars. The experimental orchards were planted during the winter of 2011-2012 on four sites. All the sites are evaluating a common list of cultivars but each site focuses on a specific pest or disease. The objective of the trial is to classify the new cultivars considering their sensitivity to powdery mildew (Sphaerotheca pannosa), peach leaf curl (Taphrina deformans), oriental peach moth (Cydia molesta/Anarsia lineatella) and thrips (Frankliniella occidentalis/Thrips meridionali). The first observations permitted classification of the cultivars according to their level of sensitivity to the tested pests and diseases. The study showed that there is no cultivar totally tolerant to all pest/diseases. Moreover, the study highlighted the importance of environmental factors on the appearance and intensity of the symptoms.