Towards an international coordinated approach to facing major grapevine epidemic diseases

24 May 2024

The International Symposium on Grapevine Epidemic Diseases took place on 17 May in Texas, Austin (USA). An event jointly organised by the Texas Department of Agriculture (TDA) and the International Organisation of Vine and Wine (OIV), in Austin (Texas).

Nearly 100 people attended the symposium, which provided an opportunity to exchange ideas, discuss issues, and learn from 15 international speakers (in the picture). Topics covered included the impact of climate change, international standards, regulatory frameworks, mitigation strategies, and the economic impact of grapevine epidemic diseases. 


The urgent need to combat grapevine epidemic diseases

The event was inaugurated by Sid Miller, Commissioner of the Texas Department of Agriculture, who welcomed participants and emphasised the collaboration between TDA and OIV. The OIV Director General, John Barker, underscored the importance of such a scientific symposium in a video message, considering the growing concerns of vitivinicultural countries about the spread of grapevine epidemic diseases, such as Pierce’s disease in North America and Mexico, and Flavescence dorée in Europe.

It was a significant occasion for both Commissioner Sid Miller and OIV Director General John Barker to acknowledge Thomas Volney Munson’s remarkable contribution to Texas and global viticulture. This legacy was recognised by presenting Heather McKinney, a descendant of T.V. Munson, with an artistic illustration of the Carmenère variety painted by a French artist.


Global strategies and scientific insights

The symposium was divided into four scientific and technical sessions:


Session One


  • Amit Dhingra, Professor and Department Head of Horticultural Sciences at Texas A&M University, USA, explained how climate change is affecting viticulture worldwide, necessitating adaptation to new adverse cultivation conditions.
  • Rodrigo Almeida, Professor at UC Berkeley, USA, highlighted the impact of climate change on the complex epidemiology of Pierce’s disease, suggesting greater attention to the disease’s vectors.
  • Elisa Angelini, a researcher at CREA VE in Italy, introduced the issue of Flavescence dorée, which has significantly spread in Europe following the recent revocation of certain insecticides effective in controlling the vector.

Session Two


  • Enrico Battiston, OIV Viticulture Head of Unit, Valerie Grimault, EPPO officer, and Sarah Brearey, NAPPO representative, presented existing standards. They highlighted the crucial role of international organisations in viticulture and plant protection, providing harmonised guidelines for controlling grapevine diseases and their vectors.

Session Three


  • Institutions working on policies in the main vitivinicultural countries presented their regulatory systems regarding the monitoring and control of diseases.
  • Allen Proxmire, USDA APHIS (Animal and Plant Health Inspection Service, U.S. Department of Agriculture) officer, emphasised the importance of controls across the US.
  • Gabrielle Vivian-Smith, Australian DAFF (Department of Agriculture and Water Resources) officer, presented the national biosecurity program.
  • Mylona Panagiota, European Commission DG SANTE officer, highlighted the impact of the new EU Plant Health Law.

Session Four


  • This session presented successful experiences applied globally to combat the spread of harmful diseases.
  • Luis Diaz-Garcia, a UC Davis researcher, introduced a breeding program to develop new grapevine varieties resistant to Pierce’s disease.
  • Jacques Grosman, French Ministry of Agriculture officer, presented a national strategy to monitor and prevent the spread of Flavescence dorée.
  • Fiona Constable, Plant Virologist at the Australian Victorian Department of Environment and Primary Industries, provided an overview of the phytosanitary measures applied in Australia, including screening imported plant material and hot water treatment. These procedures are fundamental in avoiding the biological and economic risks associated with the spread of grapevine epidemic diseases.


A final panel involving professionals and scientists from the Texan wine industry and research centres discussed the Texan approach to managing Pierce’s disease and promoting research activities for increased protection.


What should be done


A final round table, moderated by Peter Hayes, OIV Honorary President, led the speakers to debate the development of a coordinated international approach to manage epidemic diseases in grapevines. In conclusion, the following actions were suggested:


  • Reinforcement of grape breeding programs, including new biotechnological tools (NBTs) to optimise and speed up the creation of new varieties resistant to epidemic diseases.
  • A deep study of vineyard soil quality and life to set appropriate mitigation strategies against the stresses associated with the impact of climate change.
  • Paying major attention to insect vectors, as well as to their interactions with the pathogen and the plant.
  • Sharing knowledge with professionals and operators in the vitivinicultural sector through specific training programs, which should be encouraged.
  • Improvement of an international research network, constantly connected and revised to avoid redundancy in studies and the dispersion of funding.
  • Mitigation strategies must include an accurate analysis of the social impact of epidemic diseases and their control.
  • Development of a harmonised international approach, ensuring transversal discussions among scientists, national institutions, and professional associations, coordinated by the OIV and the IPPC’s regional organisations*.

The symposium was closed with remarks from Lindsay Baerwald, TDA Marketing Specialist, who commended the productive and stimulating day and expressed hope for a future edition to follow up on the first, aiming for international collective action in addressing the challenge of grapevine epidemic diseases.


* A letter of intent between the OIV and the European and Mediterranean Plant Protection Organization (EPPO) was signed in January 2024. This collaboration aims to strengthen the exchange of valuable information, expertise, and support in crucial areas such as plant protection products, phytosanitary regulations, and grapevine health. By joining forces, the organisations wish to reinforce their actions towards the preservation of grapevine health, as well as the protection of viticultural surfaces from harmful organisms. The OIV and EPPO are committed to achieving the Sustainable Development Goals, combatting climate change, and promoting sustainable development in the viticulture sector.