Asian soybean rust is a disease that causes leaf spots (lesions) and eventual defoliation of soybean plants, sometimes in a matter of a few weeks if untreated. Soybean yields are reduced due to poor pod set and seed filling because the infection reduces the plant’s ability to perform photosynthesis. The fungus that causes the disease is Phakopsora pachyrhizi. It reproduces prolifically by producing extremely small spores that are disseminated by the wind.
Asian soybean rust was first discovered i…