The International Council for the study of Viruse-like diseases of Grapevine (ICVG) recognises over 70 infectious agents (viruses, viroids and phytoplasmas) of grapevines, many of which can be highly detrimental to this crop, having a negative impact on plant vigour and longevity, as well as on quality and quantity of the yield.
Certification of grapevine nursery stock is a powerful and effective tool to control these agents, and enables vineyards to economically and sustainably maintain quality and productivity.
Certified grapevines are derived from pathogen tested, clonally selected primary sources. The certification process should specify conditions to prevent and detect subsequent infection of nursery plants by regulated pests, ensure clonal integrity, and permit tracing the certified grapevines to the originally selected and tested plantsCertified grapevines are derived from pathogen tested, clonally selected primary sources. The certification process should specify conditions to prevent and detect subsequent infection of nursery plants by regulated Inadequate certification standards have repeatedly resulted in disease problems for growers and nurserymen.
Infected propagation material is largely responsible for the spread of diseases among and within viticultural countries. Thus, all efforts should be made to improve its sanitary conditions., ensure clonal integrity, and permit tracing the certified grapevines to the originally selected and tested plants.
Inadequate certification standards have repeatedly resulted in disease problems for growers and nurserymen.
Infected propagation material is largely responsible for the spread of diseases among and within viticultural countries.Thus, all efforts should be made to improve its sanitary conditions.
However, valuable grape genetic resources exist which are infected with virus but are essential to the preservation of world viticultural heritage.
In orderd to preserve valuable grape clones and varieties, we propose two sanitary classes. Certified selections should be tested for specific pathogens. Class 1 should include only grape nursery stock that tests negative for the most damaging diseases/pathogens. It would move freely between regulatory boundaries. Class 2 would be a specific pathogen tested certification system for stock that remains within regulatory regions and is only distributed with disclosure of virus status. No other stock should move outside regulatory regions.
In order to preserve valuable grape clones and varieties, we propose two sanitary classes. Certified selections should be tested for specific pathogens. Class 1 should include only grape nursery stock that tests negative for the most damaging diseases/pathogens. It would move freely between regulatory boundaries. Class 2 would be a specific pathogen tested certification system for stock that remains within regulatory regions and is only distributed with disclosure of virus status. No other stock should move outside regulatory regions.
The agents that should be controlled by the Class 1 certification program are
those associated with infectious degeneration and grapevine decline (nepoviruses);
leafroll disease and associated closteroviruses (grapevine leafroll associated viruses 1, 2, and 3); rugose wood ( GVA, GVB and GVD);
and phytoplasmas (flavescence doree, bois noir, and other grapevine yellows).
In the future, technology should make it possible to exclude additional disease causing viruses from the certified stock including the casual agents of fleck and rupestris stem pitting. Until that time, a moratorium will be established for these viruses.
European and other regional certification standards for Class 2 stock should be created at a local level based on the level of endemic infection, regional viticultural conditions, and the need for preservation of heritage germplasm.
As all efforts are made to harmonize world grapevine certification protocols, high standards are essential to ensure that no viticultural area is compromised by the introduction and spread of diseases.
