Anthracnose: Identification, Prevention, and Control

Anthracnose is a fungal disease attacking emerging leaves and shoots in spring, causing large irregular brown blotches on older foliage. On tomatoes and peppers, small water-soaked fruit spots enlarge and penetrate, spoiling fruit. Twigs may show dieback and cankers. Symptoms vary by host—take a sample to your Cooperative Extension Office or full-service nursery for diagnosis.

Cultural Prevention

• Choose resistant varieties in high-rainfall areas.
• Grow vining plants on freestanding trellises away from walls/fences to keep foliage dry.
• Switch from overhead to ground-level watering.
• Prune out infected twigs/branches; rake up fallen infected leaves.
• Lime sulfur may prevent spore attachment.

Chemical Control

Chlorothalonil in spring: spray at leaf emergence, then 2–3 more times at 2-week intervals.