Blueberry viruses

Distinguishing between various virus symptoms is difficult in blueberries. Diagnoses must be validated with a lab test, and these often yield false negatives. In general, viruses are suspected if the planting is old, and if other causes of leaf deformation  or leaf discoloration  are ruled out.

Some common viruses include:

Blueberry Shock Virus

Blueberry stems with irregularly distributed healthy and dead leaves. Approximately 60% of leaves are dry, brown, and shriveled. Remaining healthy leaves are green-yellow. No obvious pattern can be fitted to dead leaf distribution, but stems nearby affected branch appear entirely healthy.
Blueberry Shock (A. Schilder, MSU)

More information on blueberry shock virus (A. Schilder, MSU)

Blueberry Scorch Virus

Blueberry bush with cluster of crimson-colored leaves. Crimson leaves appear to stem from same branch, entire branch appears affected. Crimson color is starkly marginal with green venation. Some leaves outside the cluster have paler red patches along leaf margins or in interveinal sections.
Blueberry scorch virus.

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Tobacco Ringspot Virus

Crinkled blueberry leaves with few black-purple spots. Spots are uniform in color or may have green center. Unspotted sections of leaves are green. Spots do not have obvious pattern of distribution on upper leaf surface,
Tobacco ringspot virus (necrotic ringspot) in ‘Patriot’ blueberry.
Severely crinkled blueberry leaves with upward cupping. Leaves are dark blue-green color and shiny. Two leaves have small dark purple-black spots beside leaf veins, other leaves are entirely green.
Tobacco Ringspot or Necrotic Ringspot Virus

More information on tobacco ringspot (necrotic ringspot) virus

Tomato Ringspot Virus

Blueberry leaf with mottled purple-brown discoloration along leaf margins and interveinal areas. Leaf veins are red and weakly boredered in green. Leaf is slightly crinkled.
Tomato Ringspot virus.
Dark green blueberry leaf with severe crinkling. Crinkling affects individual inter-veinal sections. Some leaves are malformed and central veins appear crooked due to disfiguration of leaf.
Tomato Ringspot virus
Blueberry stem with slightly crinkled, discolored leaves. Leaves are dark blue-green with numerous yellow speckles. Most speckles are smaller than a pinhead and uniformly yellow, larger speckles may have bronze center. Veins and stem are pale pistachio color.
Tomato Ringspot virus.

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Blueberry Leaf Mottle Virus

Crinkled, undulating blueberry leaf with green coloration.
Blueberry Leaf Mottle Virus

More blueberry leaf mottle virus information

Blueberry Shoestring Virus

Blueberry stem with thin, blackened leaves that have straplike or stringlike appearance. Healthy leaves on same branch are much wider than symptomatic leaves.
Blueberry Shoestring Virus.

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Red Ringspot Virus

Blueberry branch with crimson leaves. Crimson spotting can range from several marginal spots on a shiny green leaf, to leaves with almost uniform red color with small green patches. Red coloration appears to only be distributed in circular shape. Leaf veins remain green the longest, especially at base of leaf.
Red Ringspot Virus

Red ringspot

More information on blueberry viruses:

Virus diseases are both difficult to identify and control. The best control strategies for blueberry viruses are preventative:

  • Use only virus-tested planting stock.
  • Monitor and control virus insect vectors such as aphids and leaf hoppers to limit disease introduction and spread.
  • Identify and remove infected plants.

Use these resources if you need additional help with diagnosis and to find solutions to your problem.