Bean Rust, this fungus is found worldwide on beans especially during hot summers.
Do not confuse with:
The many fungi all called “r
Bean Rust (Uromyces appendiculatus – Uromyces phaseoli). This fungus is found worldwide on beans during hot summers. It starts with light-colored round spots on the leaves with cup-shaped fungi (pustules) on the backside of the leaves. These pustules turn to rust-brown spores that can infect the still healthy parts of the plant.
The fungus thrives best at temperatures between 17-27°C and a daytime high humidity: 95%. Beans are the host plants of this fungus. The fungus overwinters on beanstalks (!) and remaining affected plant parts.
Where to find
- Common bean (Phaseolus vulgaris)
- Runner bean (Phaseolus coccineus)
Difficult to control: after infestation, recovery is hardly possible. Remove affected plant parts and beanstalks.
Ample crop rotation and regular bean-stalk changes help prevent the fungus.