Many disorders can mimic one another. Hopefully this key provides helpful information to differentiate between disorders in the field. In many cases, submitting a sample to the Plant Disease and Insect Clinic is still needed to positively identify the problem.
The key uses a series of filters that users can select to narrow down the causal agent of a soybean disorder. In total, there are 21 insect, 33 disease, 11 nutritional and 27 physiological/herbicide related issues that the tool points toward.
Each of these has an associated fact sheet that will describe the disorder and aid in subsequent management considerations.