During the past few weeks, reports have been numerous of soybean plants with symptoms mimicking plant growth regulator (PGR) herbicide damage. Leaf cupping and malformation in soybean are not well understood; however, it seems that there are at least three circumstances that may lead to these symptoms:

1. soybean plants are exposed to a plant PGR herbicide (e.g., 2,4-D and dicamba);
2. application of a postemergence herbicide to soybean induces the response, and
3. environmental conditions stimulate the symptoms.