Systemic pathogens

Virus Disease & Vector Concepts

Plant viruses can cause mottling, distortion, stunting, or no obvious symptoms. Diagnosis requires testing because similar patterns can come from nutrition, herbicide or spray injury, mites, temperature stress, or genetic variation.

What to look for

  • Persistent mottling or mosaic-like color patterns
  • Distorted or reduced new growth
  • Symptoms repeating in clonally related plants
  • Patterns associated with a known vector or contaminated propagation chain when relevant

Important look-alikes

  • Micronutrient or root-zone disorders
  • Herbicide or spray injury
  • Mite damage
  • Genetic variegation or developmental abnormalities

How to confirm

  • Use validated laboratory testing for the suspected pathogen
  • Record plant lineage and propagation source
  • Identify any suspected vector rather than assuming transmission
  • Compare symptoms across clonally related material

Management principles

  • Do not propagate confirmed infected stock
  • Separate suspect material while testing
  • Control established vectors when a verified vector relationship exists
  • Sanitize propagation practices to limit mechanical or stock-mediated spread where relevant

Prevention

  • Use clean tested mother stock when available
  • Quarantine incoming clones
  • Maintain propagation records
  • Train staff not to diagnose viruses visually

Visual study guide

  • Virus symptom differential plate
  • Propagation transmission map
  • Vector concept diagram
  • Testing workflow

Connected learning

Use the next piece of evidence

Move between reference material, measurement, field records, and whole-plant context instead of treating one page as the complete answer.