Plant Diseases: Rust

Photo Credit: Flickr, IITA Image Library

Rust is one of the most common fungal plant diseases. The rust fungi will cause unsightly, small, yellow spots on the surface of the leaves and a brown, orange or black powdery residue underneath. The disease is not deadly, but can cause leaves to fall off early and weaken the plant.

Unlike other fungi, rust tends to affect healthy plants, usually during late summer or early fall. The disease is spread by spores in the air. As a fungal disease, the rust will flourist in wet conditions.  Rust can affect trees, flowers, grasses and plants such as hollyhocks, fuchsias, roses, and chrysanthemums. The disease generally affects the leaves, but symptoms can also show up on the stems, flowers and fruit.

Treatment:

• Prevention is the best cure for rust. Choose disease-resistant plants.
• Remove affected leaves immediately.
• Prune crowded plants to improve the air circulation.
• Try to avoid over fertilizing the plant, as too much nitrogen will produce more leaves for the disease to affect.
• Avoid overhead watering.
• Neem oil, a natural fungicide and pesticide, can help control rust.
• Chemical fungicides can also be used to treat the rust, but is often used as a last resort.

Other Plant Diseases:

• Powdery Mildew (funflowerfacts.com)
• Black Spot on Roses (funflowerfacts.com)
• Plant Pests & Diseases (growerdirect.com)