We are seeing immature soybean once again sprouting in the pods in Suffolk and Gloucester County, and I heard of this happening in other states. This seems to occur every 3-6 years somewhere. Although I don’t have a great explanation for why this occurs, it usually happens when there are good growing conditions early followed by 2-4 weeks of drought stress during pod formation, and then excellent conditions return for seed fill. Typically, it happens in big-canopied soybean (lots of leaf area) with lots of yield potential, but not enough pods (or big enough pods) to fulfill that potential. I think that the seeds enlarge so much that the pod splits.
Keep in mind that I’m talking about immature seeds and pods. This can also occur after the crop matures (R7 to R8) when we get excessive rainfall after the seed in question has dried down. But, I have not seen that yet this year.
There is little that you can do about it. Those sprouted seed will usually dry up on the plant and be blown out the back of the combine.
Although there has to be some yield loss, I’ve not seen it to be very great. And, I suspect that if you did not notice the sprouted seed, you probably would not know that you had a loss.
For more information, see previous blogs on this subject.