Anthracnose
Anthracnose is a fungal disease caused by Colletotrichum species, affecting a wide range of plants. It manifests as dark, sunken lesions on leaves, stems, flowers, and fruits, often leading to defoliation and reduced plant vigor.
About this problem
Anthracnose is a common plant disease caused by various species of the fungus Colletotrichum. It primarily affects the foliage, stems, flowers, and fruits of a wide range of plants, including trees, shrubs, and vegetables. The disease is characterized by the development of dark, sunken lesions that can cause significant damage if not managed properly. The fungus thrives in warm, humid conditions, making it more prevalent in certain climates and during specific seasons. Over time, the lesions can expand, leading to defoliation and reduced plant vigor. Anthracnose is often confused with other leaf spot diseases, but its distinct sunken lesions help in its identification.
Symptoms
- Dark, sunken lesions on leaves
- Leaf drop
- Brown spots on leaves
- Wilting
- Sunken lesions on fruits
- Stem cankers
Cause
Anthracnose is caused by the fungus Colletotrichum, which thrives in warm, humid conditions. The spores are spread by rain, wind, and contaminated tools.
Conditions that favour it
- Warm temperatures
- High humidity
- Frequent rainfall
- Poor air circulation
- Overhead watering
Lifecycle and spread
The fungus overwinters in plant debris and infected plant material. In spring, spores are produced and spread by rain and wind. The cycle can be broken by removing infected debris and improving air circulation.
Plants most affected
- Maple
- Oak
- Sycamore
- Tomato
- Cucumber
- Bean
- Pepper
- Strawberry
- Avocado
- Citrus
Treatment
Educational information only, and not a substitute for professional diagnosis. Identify the problem before treating it, and check that any product is registered for this plant and this use where you live.
Cultural control
- Prune infected plant parts
- Increase plant spacing for better air circulation
- Avoid overhead watering
- Remove and destroy fallen leaves and debris
Organic options
- Neem oil
- Copper-based fungicides
- Bacillus subtilis
Chemical options
- Chlorothalonil Used to manage fungal infections
Read and follow the product label. The label is the legally binding instruction. Confirm the product is registered for this plant and for this use in your area before applying it.
Prevention
- Plant resistant varieties
- Ensure good drainage
- Maintain proper plant nutrition
- Implement crop rotation
- Regularly inspect plants for early signs