Rust (fungus – Puccinia sorghi): The importance of this rust on oxalis is that its alternate host is corn. On oxalis, the rust first appears as neat, yellowish dots near the margins of the leaves; later pale orange pustules break out on the leaf. Usually does not cause enough damage to warrant control.
Beet Curly Top (virus): (See the section on Curly Top)
Powdery Mildew (fungus- Microsphaera russellii): White, powdery blotches on foliage.
Smut (fungus – Ustilago oxalidis): Reported in Texas.