Soybean rust is a type fungus which we know in two difficult to distinguish forms of Phakopsorapachyrhizi and Phakopsora meibomiae. The P.meibomiae (or New World soybean rust) strain is less virulent than p.pachyrhizi (also known as Australasian soybean rust), and it is found typically only in the western hemisphere, while P.pachyrhizi has been noted now in the western hemisphere, it originates from Asia. Either way these two fungi attack legumes which includes soybean, which the US is a major grower of it at approximately one third of the world’s production which is slowly increasing year by year.

Spread of this fungus is thought to be spread by storms carrying the spores. While freezing temperatures prevent its growth, winds are known to quickly spread the spores. The storm clouds are thought to protect the spores from ultraviolet radiation. The fungus is difficult to detect in the early stages of its 7-8 day cycle, typically not noted on soybeans except during the flowering stage of the legume. Per a Congressional Research Service report from 2005, the Soybean Rust fungus has reduced yields of soybean by 10%-80%. The report cites a USDA report that economic losses could range from $240 million to $2 billion for the southern US states in severe outbreak.

Controlling the fungus is a three-prong attack: fungicides, cultivating genetic resistance, and culture. While fungicide application is straight forward for the agriculture community familiar with its application, genetic resistance is different kind of battle. The cultivation of genetic resistance is a cyclic game of identifying dominant genes resistant followed by new types of the fungus emerging a few years later. Cultural practices means changing the planting and harvesting behavior of the crop grower. Shifting to either earlier or later dates help avoid impacts of fungus damage or during climates too dry for the fungus, respectively