Over the past 20 years, sudden death syndrome, caused by the soilborne fungus Fusarium solani f. sp. glycines, has emerged as an important production problem in the southern part of the US soybean belt. More recently, the disease has appeared in some production areas of the north-central US, and soybean producers there are concerned that it will become more prevalent in the future. Temperature, moisture, and cold stress response functions for sudden death syndrome were derived in controlled experiments and used with long-term monthly temperature and rainfall normals and regional data on soil moisture storage capacity in a generic pest risk model to determine the potential geographical range of the disease. The analysis suggests that sudden death syndrome is restricted by low moisture west of the Missouri River, and by cold stress north of 43–44 degrees latitude. It is further suggested that production areas in the heart of the north-central region, including large parts of Illinois, Indiana, and Ohio, are located within the range favorable for the disease. These results will be important for allocation of resources for resistance breeding and disease management research.
