I think the disease is rust. A fungal disease attacks the leaves, pods and shoots. The first signs of rust are tiny specks or spots on leaves that range in color from orange to rusty-brown, brownish-yellow, purple and red. Left untreated, the spots get bigger and turn into bumpy-looking pustules. Eventually, the pustules break open and release spores that are spread by wind or splashing water. As they land on other plants, the spores infect them, too.

Hot, humid weather favors rust attack, and it can be tough to eliminate.

Use pruning shears to cut away entire shoots that have affected leaves and bean pods. While it's possible to prevent the spread of the fungus by removing individually affected leaves and pods, the fungus may have already spread to an adjacent leaf.