Grapevine Virus Resources

CGCN Resources

Browse these resources to learn about some of the common grapevine viruses that the Canadian Grapevine Certification Network certifies against.

Red Blotch | CGCN

Red Blotch
Grapevine Red blotch, Geminiviridae

A viral disease of grapevine, Red Blotch is caused by a single-stranded circular DNA virus First identified in California, Red Blotch affects grapevines of all varieties and is internationally present.

Season

Visible symptoms observed mid to late summer.

Notes

Red Blotch symptoms can often be seen as potassium or magnesium deficiencies or as grapevine leafroll virus.

Possible Known Vectors

  • Propagation
  • No other known vectors at this time

Visual Symptoms

  • Red spots of blotches on leaves
  • Mature, infected leaves dropping off vines
  • 30-50% smaller clusters
  • Uneven ripening or failure to ripen
  • 20-50% reduction in sugars
  • Poor pigment

Leaf Roll | CGCN

Leaf Roll
Grapevine leafroll-associated closteroviruses (CLRaV)

Grapevine leafroll-associated virus is a name for a group of viruses infecting grapevine in the genus Closterovirus.

Season

Visible symptoms observed mid to late summer.

Notes

There are a number of leafroll viruses, aptly named Leafroll 1, 2,3,4,5,6, and 7, each displays very similar symptoms.

The most prominent leafroll’s at this time are Leafroll 1 and Leafroll 3.

Leafroll symptoms can often be seen as potassium or magnesium deficiencies or leafhopper damage.

Possible Known Vectors

  • Mealybug
  • Scale insects (planococcus ficus, Pseudococcus affinis, Ps.longispinus)
  • Propagation

Visual Symptoms

  • Shorter shoots
  • Smaller leaf size
  • Reddish leaves in red varietals or yellowish leaves in white varietals with main vein of leaf staying green
  • Downwards rolling of leaves
  • Smaller fruit clusters
  • Late and irregular maturity in fruit
  • 20-50% reduction in sugars
  • Loss in yields
  • Low brix
  • High acids
  • Shorter vineyard life
  • Poor pigment
  • Reduced yield

Pinot Gris Virus | CGCN

Pinot Gris Virus
Grapevine Pinot Gris Virus

Grapevine Pinot gris virus is a positive sense single-stranded RNA virus in the Trichovirus genus that affects the growth of grapevine leaves and fruit.

Season

 Some incidences, there may be no symptoms of the virus shown in vines.

Notes

The virus is not exclusive to pinot gris/pinot grigio grapevines, as the name would suggest, but has the possibility of infecting any varietal.

Possible Known Vectors

  • Mites
  • Propagation

Visual Symptoms

  • Delayed budburst
  • Distortion and mottling of leaves
  • Reduced yield

From Our Team

  • The industry's long-term sustainability depends on our capacity to develop adaptive, innovative solutions that respond to the impact of both current and future climatic conditions on wine grape production.
    Jill Page, CGCN
Questions? Feel free to contact us.

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