Symptoms on Leaves

Choose the type of symptom occurring from the following categories:

Broad & Irregular Lesions:

• Water-soaked lesion turning dark brown or beige with white sporulating growth in wet weather
• Lesion with gray fungal sporulation
• Zonate shaped lesions during wet weather

Chlorosis & Fungal Growth:

• Chlorotic lesion on upper surface, sporulation on lower surface
• Whitish fungal growth, mainly circular on upper surface

Circular Spots: black or dark brown and varying in size

Insect-related Damage

Nutrient Deficiencies

Physiological Disorders & Phytoplasmas:

• Big bud of floral parts
• Green callus-like growth on upper and lower surface
• Leafroll without yellowing or rugosity

Pesticide Damage:

• Insecticide injury
• Virus-like symptoms caused by herbicides

Virus Symptoms:

• Chlorotic mottling or fernleaf under cool growing conditions
• Dark brown streaks on foliage, stems, and fruit
• Green mottling or fernleaf appearance
• Leaf distortion and mottling
• Leafroll, marginal yellowing and rugosity
• Yellowing, bronzing, or calico with plant stunting

Yellowing, Necrosis & Wilting:

• Marginal browning with necrotic spots and irregular interveinal lesions later in disease development
• Other yellowing, necrosis, and wilting of 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.