Rust and Beans

Rust is a fungal disease that commonly occurs in Florida where it’s warm and humid. Most beans are susceptible to Rust. The disease generally occurs only during prolonged periods of warm, wet and/or humid weather.

Rust refers to a variety of fungus, exists in at least 35 pathotypes and is extremely variable. Symptoms develop on leaves and pods as pustules of red-brown powdery spores which rupture the epidermis. They are often surrounded by yellow. Severely infected leaves turn chlorotic, rust-colored, dry, and eventually die. This disease can be spread from plant-to-plant.

Like most diseases, the best solution is prevention. While beans can be planted four inches apart, if your water source is not a drip system, or applied directly at the base of the plant, it’s best to space your bean plants further apart. Allowing air flow between plants will reduce the buildup of heat and moisture which exacerbates the problem. As you can see, mine are planted very close together and have developed rust at the base–right next to my irrigation spray. Duh.

The zucchini plant next to them isn’t helping matters, especially since it’s also very susceptible to fungal diseases. Yes, I’m a Master Gardener and should know better, but in my defense, if Mother Nature had been cooperating, I wouldn’t be in this predicament. Usually dry and breezy, this October has felt more like July! Go figure. I still have beans. And that’s the bottom line. Happy gardening!