Grapevine viruses: a multitude of diverse species with simple but overall poorly adopted management solutions in the vineyard

Eighty-six viruses have been isolated to date from grapevines worldwide. Some of these viruses are associated with economically damaging diseases such as leaf mottling and deformation, vein clearing, leafroll, degeneration and red blotch. They belong to the families Betaflexiviridae, Caulimoviridae, Closteroviridae, Secoviridae and Geminiviridae, and are transmitted by diverse vectors such as mealybugs (Hemiptera: Pseudococcidae), soft scale insects (Hemiptera: Coccidae), an aphid (Hemiptera: Aphididae), dagger nematodes (Nematoda: Longidoridae), a treehopper (Hemiptera: Membracidae) and eriophyid mites (Acari: Eriophyidae). Management of these viruses primarily relies on preventive measures to limit their presence in the propagation and planting material. In the vineyard, specific disease scenario-based strategies such as rogueing in combination with agrochemical applications to limit vector populations, if appropriate, and the removal of entire parcels and their replacement with clean planting material, including vector tolerant rootstocks, if opportune, are implemented to reduce their incidence, prevent their spread and mitigate their impact. These solutions are simple but their implementation is often suboptimal and their adoption is largely low. Some of the uncertainties that hinder their endorsement are captured here, and options to refine them and to enhance their adoption are discussed.