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Verticillium Wilt

by Elizabeth H. Roche, Nancy J. Taylor & Francesca Peduto Hand


Verticillium enters and colonizes the roots of host plants invading the xylem tissue. As a result of the fungus activity and the plant’s reaction to the invasion, the vascular system clogs preventing water and nutrients from moving throughout the plant. As a consequence, symptoms of the disease are characteristic of a non-properly functioning vascular system, including:

  • Stunting
  • Wilting
  • Leaf chlorosis
  • Leaf scorch
  • Defoliation
  • Brown-black discoloration (streaking) of xylem tissue may be present (visible in longitudinal or cross-sections). Since this is almost identical to that caused by Fusarium wilt, a confirmatory laboratory diagnosis is recommended.

Microscopic observation of infected tissues may reveal the presence of tiny black structures (microsclerotia).

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For assistance in identification, contact the C. Wayne Ellett Plant and Pest Diagnostic Clinic.

Management Guidelines

  • Use resistant cultivars whenever possible.
  • Use culture-indexed pathogen-free plants.
  • Check incoming plant material for symptoms before introducing them into production.
  • Remove and destroy any symptomatic plant.
  • Control insect pest populations.
  • Adopt proper soil sanitation practices. Always use clean soil. Soil can be disinfested by steam (140°F for 30 min), solarization (double tent at 160°F for 30 min or 140°F for 1 hour), or chemical treatment (fumigation).
  • For field production of cut flowers, avoid fields that have previously hosted susceptible crops.
  • Fungicides are generally not effective for disease control.