Many problems can occur during the reproductive stages of soybeans, including insect feeding, stunted pods or damage or discoloration to leaves and stems. And, there are many potential causes too, from pests to a virus to a fungus.
Check out THIS ARTICLE from United Soybean Board to see some common problems with soybeans in reproductive stages and their causes to help diagnose and treat them.
The featured image in this article is from: graincrops.blogspot.com/2013/08/frogeye-leaf-spot-of-soybean-active.html