Grapevine Leafroll Virus: A Damaging Disease
Introduction
Grapevine leafroll virus is a serious disease that affects grapevines worldwide. It is responsible for nearly 60% of crop losses in grapes each year. This disease is present in all grape-growing regions and can impact any grape variety or rootstock. If you grow grapevines, it is important to be aware of leafroll and what you can do to prevent and manage it.
What is Grapevine Leafroll?
Grapevine leafroll is a viral disease that is difficult to identify. The symptoms are not always obvious until well into the growing season, and sometimes there are no visible symptoms at all. Other diseases can cause similar symptoms, making it even more challenging to diagnose.
Symptoms of Grapevine Leafroll
The symptoms of grapevine leafroll can vary depending on the age of the vines, the environment, and the grape variety. However, some of the most common symptoms include:
- Rolling or cupping of the leaves
- Reddening of the leaves in the fall (on red grapevines)
- Green veins on reddened leaves
- Reduced vigor
- Late fruit development
- Poor quality fruit with reduced sugar content
- Reduced yield
Transmission of Grapevine Leafroll
Grapevine leafroll virus is primarily transmitted through infected plant material, such as pruning tools that have been used on an infected vine and then on a healthy vine. There may also be some transmission through mealybugs and soft scale.
Management of Grapevine Leafroll
Once grapevine leafroll virus is established in a vineyard, it is challenging to control. There is no cure for the disease. However, there are some steps that can be taken to prevent the spread of the virus, including:
- Using only certified, clean vines
- Disinfecting tools used on vines with bleach
- Controlling mealybugs and soft scale
Conclusion
Grapevine leafroll virus is a serious disease that can have a significant impact on grape production. By understanding the symptoms of the disease and taking steps to prevent its spread, growers can help to protect their vineyards from this devastating disease.
Additional Information
- How to identify grapevine leafroll virus: Look for the symptoms listed above, such as rolling leaves, reddening leaves, and reduced vigor.
- What are the best grapevine varieties for resistance to leafroll? Some grape varieties are more resistant to leafroll than others. Ask your local nursery or extension agent for recommendations.
- How to test for grapevine leafroll virus: There are several tests available to test for grapevine leafroll virus. Your local nursery or extension agent can help you choose the right test for your needs.
- Where to buy certified grapevines: Certified grapevines are vines that have been tested and found to be free of leafroll virus and other diseases. You can purchase certified grapevines from reputable nurseries or online retailers.
