Rust
Pucciniales
A group of fungal diseases that affect many types of plants. Rusts are named for the reddish-orange, powdery pustules that appear on infected plants.
Symptoms
- Small, reddish-orange, yellow, or brown pustules on the undersides of leaves.
- Yellow or white spots on the upper surfaces of leaves.
- Stunted growth and leaf distortion.
- Premature leaf drop.
Causes
- Specific fungi that are often host-specific.
- Spores spread by wind and water.
- Mild, moist weather conditions.
Prevention
- Plant resistant varieties.
- Avoid overhead watering.
- Ensure good air circulation.
- Remove and destroy infected plant material.
Treatments
- Prune affected areas to increase airflow.
- Apply sulfur or copper-based fungicides.
- Use neem oil as a less toxic alternative.