Strategy to control Plum Pox Virus damage (BIOFRUITNET Practice Abstract)

Growing PPV-resistant varieties combined with PPV-resistant rootstocks improve fruit-growing economics and financial return. Practical recommendations • HOST PLANTS: All stone fruit species, PPV mainly infects plum trees. Apricots, peaches, nectarines, and sweet and sour cherries can be infected by different strains of the virus • SYMPTOMS of the Plum Pox Virus disease: o On leaves: Ring-shaped chlorotic spots and marks, mostly diffused, bright green o On fruits: Deformations, ring-, line- or pox-like depressions or shrivelling fruit • DAMAGE: o Fruits have lower sugar content, worse appearance, and are unsuitable for fresh sale consumption o Fruits fall prematurely to the ground, and fruit quality and yield is lower o Infected trees have lower assimilation due to chlorotic spots, and tree vigour is lower DISEASE TRANSMISSION: o PPV damage occurs mainly after planting of infected plant material, and the virus is spread by aphids in orchards o Vegetative, especially by vegetative reproduction (scions, grafts) o PPV can also be spread during tree pruning through non-disinfected pruning devices • PROTECTION: Treatment against PPV does not exist yet, so the application of preventive measures is the only effective way of disease control. Direct control only reduces the next virus spreading o PREVENTIVE MEASURES: Use certified virus-free plant material, and grow resistant varieties grafted onto resistant rootstocks to fully protect trees against PPV infection o DIRECT MEASURES: Destroy all infested trees and control aphids (the vector of PPV transmission) for the purpose of decreasing the additional spreading of PPV within the orchard • PPV-resistant plum varieties: Jojo, Jofela, Joganta, Jolina, and Moni • PPV-resistant plum rootstocks: Docera 6, and Dospina 235 • Growing resistant varieties on resistant rootstocks avoid PPV infections in plum orchard