What is Asian soybean rust?
Asian soybean rust is a fungal plant disease that affects soybean and several other crops and weeds in the bean family. On beans, rust appears as small, angular tan to reddish-brown spots on the lower surfaces of leaves. Spots are often clustered over the leaf veins. Spots may merge together to form larger lesions, and within each lesion may be several small volcano-like bumps or pustules on the underside of the leaf, from which spores are produced. The leaves of severely affected plants turn yellow and fall off, causing significant yield loss. The fungus is spread from plant to plant by tiny, dust-like spores that are carried by the wind. Wet conditions are necessary for infection to occur. Warm, but not hot, wet weather favors the disease. On soybeans, Asian soybean rust can cause up to 80 percent yield loss under extreme conditions, and proper management is critical. There is little information available regarding how serious the disease may be on garden beans. A similar disease, co
