Anthracnose | Atlanta, Georgia

sycamore leaf displaying signs of anthracnose

Anthracnose | Signs and Symptoms

Generally found in the eastern part of the United States, anthracnose is caused by fungi in the genus Colletotrichum, a common group of plant pathogens that are responsible for diseases on many plant species. Infected plants develop dark, water soaked lesions on stems, leaves or fruit. The centers of these lesions often become covered with pink, gelatinous masses of spores especially during moist, warm weather. Anthracnose can reduce a beautiful harvest into rotted waste in just a few days.

The fungal disease overwinters in and on seeds, soil and garden debris. Cool wet weather promotes its development, and the optimum temperature for continued growth of the spores is between 75-85˚F. Moisture is required for development and germination of the fungus as well as for infection of the plant. It is spread by wind, rain, insects and garden tools.

Management Strategies

  • Choose resistant plant varieties when possible and use western grown seeds which have not been exposed to the disease.
  • If this fungal problem is common, do NOT save your own seed from plantings.
  • To avoid spreading the disease, keep out of gardens when plants are wet and make sure to disinfect all garden tools (one part bleach to 4 parts water) after use.
  • Do not compost infected leaves, fruit or stems and thoroughly clean up garden areas in the fall, after harvest, to reduce over wintering sites for the fungal spores.
  • Safely treat most fungal and bacterial diseases with SERENADE Garden. This broad spectrum bio-fungicide uses a patented strain of Bacillus subtilis that is registered for organic use. Best of all, SERENADE is completely non-toxic to honey bees and beneficial insects.
  • Liquid copper sprays and sulfur powders should be applied weekly, starting when foliage begins to develop in the early spring and continuing throughout the growing season. Spray early in the day, and avoid applications during hot weather. Seeds may also be treated prior to planting.
  • Neem oil spray is an organic, multi-purpose fungicide/insecticide/miticide that kills eggs, larvae and adult stages of insects as well as prevents fungal attack on plants. Apply early, at the first sign of spring budding, every 7-14 days as a preventative measure or on a 7-day schedule until existing problems are eliminated.
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