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Virus Symptoms

Chlorotic mottling or fernleaf under cool growing conditions:
  • Tobacco (tomato) mosaic virus
diseased tomato leaves
Photo courtesy of T. A. Zitter, Cornell University, NY.

Symptoms: common strains cause mottled areas of light and dark green on the leaves. Aucuba strains cause yellowing. Leaves may also exhibit leafrolling and fernleaf-like symptoms.

Dark brown streaks on foliage, stems, and fruit:
  • Tobacco mosaic and potato virus X-double streak
diseased tomato plant with fruit
Photo courtesy of T. A. Zitter, Cornell University, NY.

Symptoms: a mixture of two viruses prompts dark brown to black streaks with downward leaf curling.

Green mottling or fernleaf appearance:
  • Cucumber mosaic virus
diseased tomato plant
Photo courtesy of T. A. Zitter, Cornell University, NY.

Symptoms: leaves are susceptible at all stages and symptoms can include mottling and sever fernleaf or “shoestring” appearance. Occurrence of satellite viruses can greatly modify symptoms. Symptoms can resemble 2,4-D herbicide injury.

Leaf distortion and mottling:
  • Tobacco etch virus
diseased tomato plant
Photo courtesy of T. A. Zitter, Cornell University, NY.

Symptoms: leaves are susceptible at all stages of development and will show mottling and distortion.

  • Curly top virus
diseased tomato plant
Photo courtesy of A.F. Sherf, Cornell University, NY.

Symptoms: plants have an erect growth habit with stunting and upward curling leaves.

  • Pseudo curly top virus
one diseased and one healthy tomato plant
Infected tomato on the left with a healthy comparison on the right. Photo courtesy of T. A. Zitter, Cornell University, NY.

Symptoms: plants are stunted with greatly reduced foliage and upward curling leaves. Spread by treehoppers, often found in south Florida.

  • Potato virus Y
diseased tomato leaf
Photo courtesy of S. Green.

Symptoms: faint mottling and slight distortion with veinbanding mosaic. Field symptoms include dark brown dead areas.

Leafroll, marginal yellowing and rugosity:
  • Tomato apical stunt
stunted tomato plant
Photo courtesy of B. Walter.

Symptoms: stunting, apical proliferation, leaf narrowing, chlorosis, necrosis, crinkling and brittleness of leaf tissue.

  • Tomato bunchy top
distorted tomato leaves
Photo courtesy of J. Ladipo.

Symptoms: stunting, apical proliferation, leaf narrowing, chlorosis, necrosis, crinkling and brittleness of leaf tissue.

  • Tomato planta macho viroid (TPMVd)
diseased and distorted tomato plant
Photo courtesy of J. Galindo.

Symptoms: stunting, apical proliferation, leaf narrowing, chlorosis, necrosis, crinkling and brittleness of leaf tissue.

  • Tomato yellow leaf curl virus
diseased tomato plant
Photo courtesy of J. Watterson.

Symptoms: plant stunting and pronounced chlorotic leaves that curl upward. Devastating disease of cultivated tomato in tropical and subtropical regions worldwide, now present in southern U.S.

  • Potato leafroll virus
diseased tomato leaves
Photo courtesy of T. A. Zitter, Cornell University, NY.

Symptoms: leaf rolling and marginal leaf chlorosis.

Yellowing, bronzing, or calico with plant stunting:
necrotic and chlorotic tomato leaves
Photo courtesy of Meg McGrath, Cornell University, NY.

Symptoms: leaves will show yellowing, bronzing, and distortion as disease progresses.

  • Alfalfa mosaic virus
three diseased tomato leaves
Photo courtesy of T. A. Zitter, Cornell University, NY.

Symptoms: yellowing and purpling develop on mature plant leaves while calico symptoms appear on young leaves.

 

More information/prepared by:

  • For more information, please contact:
    Meg McGrath – mtm3@cornell.edu & Chris Smart – cds14@cornell.edu
  • Originally prepared for Vegetable MD Online by Thomas A. Zitter.