Source: University of Missouri
Since a significant number of acres were just planted and are only now emerging, soybean foliage diseases have not been particularly widespread or severe so far this season. Low levels of Septoria brown spot on the first true leaf of very early planted soybean plants have been observed. However, the recent period of wet weather and wind driven rains may lead to the appearance of foliage diseases such as Septoria brown spot or bacterial blight. Frogeye leaf spot, downy mildew and bacterial pustule are the other foliage diseases likely to occur on soybeans during the mid-season period.
In most years the soybean foliage diseases occur in low levels and do not cause significant losses. However, under favorable conditions for disease development, losses can be serious.