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

Summary

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 orchards