Rust - Fungal Disease
Rust on yucca
Fungal disease that appears as a browning or reddening of the foliage, and a release of rusty, powdery spores. It can overwinter and infect new shoots as they emerge the following spring. Rust is moved from plant to plant by wind. To control, spread plants to allow air circulation and plant resistant varieties. Remove infected plants and thoroughly compost them.
This is a disease that can be found on most turfgrasses, although zoysia may be the most severely affected. The rust develops orange or brown pustules on the leaves. If you get enough of these on a leaf, the plant’s ability to manufacture food is reduced and the turf thins out.