What’s causing flat pods in Virginia soybeans?
In addition to the flat pods, I think we’ll also see smaller seed that we have in the past. Seed size is usually the second most important component of yield, behind pod number. But with the large number of flat pods (less seed per pod), we may not see as big of an effect on seed size, especially with the recent rainfall. Regardless of whether the problem is aborted seed within the pod or seed size, our yields will likely be lower than we think they will based on a visual inspection because of less seed per pod or smaller seed.
Finally, keep in mind that a combination of things (drought stress, disease, etc.) may be causing the flat pods. In my experience, I rarely can attribute such an event to just one factor. If you take the “glass half full” attitude, this could be an opportunity to discover an unknown problem (nematodes, compaction, improper variety selection, etc.) and begin future efforts to solve the problem. If this is occurring in just one field and not another that is close by; then it’s an opportunity to find out what’s wrong with that field.
The take-home message is that soybean will compensate for stresses by either dropping pods, producing less seed per pod, aborting seed (resulting in flat pods), or reducing seed size, depending on when the stress occurs. The timing of the dry weather following a very wet year that resulted in a heavy pod load likely resulted in the flat pods that we’re experiencing.