Soil salinity is a serious problem in North Dakota which can affect growth and yield of soybean (3, 8). There is published research showing that salinity also affects the activities of plant pathogens and the interactions of pathogens with crops. Some examples of the effects of salinity are: 1) salinity stress predisposed dry bean to infection by Macrophomina phaseolina the cause of charcoal rot (9); 2) salinity stress predisposes chile pepper to infection by Phytophthora capsici (7); 3) and salt stress increased root rot of tomato caused by Phytophthora parasitica (1). Unfortunately, in soybean, there has been limited research on the effect of salinity on diseases. Increased soil chloride was reported to increase sudden death syndrome of soybean in Arkansas (6) and there was greater soybean cyst nematode egg densities associated with plants growing in soil with higher chloride levels (6), but both effects of chloride were dependent on the cultivar. The evidence supports an interaction of cultivar by pathogen by salt concentration. Another study conducted in growth chambers reported four different chloride salts when added to soil all increased losses caused by Phytophthora sojae, the cause of Phytophthora root rot of soybean (2 ). These studies suggest that an in-depth examination of the effect of saline conditions on the resistance of soybean cultivars to major diseases in North Dakota is warranted.