Bean Rust
Rust of Bean
Most beans are susceptible to Rust caused by Uromyces appendiculatus, but the disease occurs sporadically and is important only under prolonged periods of warm, moist weather. The Rust fungus exists in at least 35 pathotypes and is extremely variable. Symptoms develop on leaves and pods as pustules of red-brown powdery spores (urediniospores) which rupture the epidermis. They are often surrounded by a yellow halo. Severely infected leaves turn chlorotic, dry, and decline. Later, black to brown teliospores form within pustules and enable the pathogen to survive between crop cycles.
Management:
- Rotate bean with non-host crops.
- Plow under infected crop residues.
- Eliminate volunteer bean plants.
- Select planting dates and schedule irrigation to avoid long periods of leaf wetness when temperatures are warm.
- Disinfect poles in production of pole beans.
- Avoid over application of nitrogen and ensure adequate potassium fertilization.
- Plant resistant cultivars.
- Sulfur and myclobutanil fungicides may provide some protection
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