Cochliobolus heterostrophus is a fungal plant pathogen. It can cause Southern corn leaf blight in Maize. Cochliobolus heterstrophus is found in many tropical regions and in the southern part of the US. Cochliobolus, although not currently the most economically serious disease, can be a very serious crop disease. C. heterostrophus (race O) was considered a mild pathogen of corn, and was of little worry to those growing maize crops. It was not until the 1970s that C. heterostrophus (race T) destroyed more than 15% of the U.S. corn crop. Race T differed from race O in the sense that it produced T-toxin (host-selective toxin). The corn planted in the 1970s carried T-cms; T-cms was particularly susceptible to T-toxin. T-toxin is considered to be related to a family of linear polyketides.