Aborted Pods in Soybeans

Earlier this week I drove out to check this soybean field and was concerned when I saw those white leaves on the top of many soybean plants. I feared it was pods that had broken open and dropped the beans to the ground. I have seen that a couple times over the last few decades. When harvest is delayed and the beans have gone through a number of cycles of dry and wet the pods can get brittle and break open. Then you see the inside of the pods which are white still attached to the plant.

When I stopped and walked into the field I quickly realized the bean pods had not broken open because there were no beans laying on the ground. Looking closer at the white leaves I saw they were actually bean pods that did not develop. The beans developed flowers at the top of the plant, set pods and then they aborted and did not develop further!

I had a pretty good idea why the top pods aborted and my agronomist agreed. With the cool weather, the days getting shorter and a lot of cloudy days the bean plants sensed they would not have enough time to fill the pods and they were aborted. The beans fill the pods from the bottom of the plant to the top. This very same variety was planted by the middle of May and I did not see the aborted pods. The field with the aborted pods was planted early in June because it rained for two weeks.

The pods that did not fill likely represents a yield loss of 3 to 5 bushel an acre. However, if all the pods were so brittle they were breaking open the losses would have been much greater.