Frost Damaged Soybeans

Now I would like to talk a little about the differences between how soybeans react to frost as opposed to corn. In the last post I talked a little about frost damage on corn. And because of the way corn grows, a frost early in the season usually doesn’t cause serious problems. When we look at soybeans the game changes, soybeans don’t have the protection from frost that corn does because the growing point of the soybean plant is exposed as soon as it emerges. Just like we talked about with corn, the best thing to do with soybean is have a little patience to see if the individual plants will survive. This picture shows what to look for when assessing frost damage on soybeans.

If the plant was damaged by frost below the cotyledonary node, it will not survive. But if the plant was injured by frost, but only down to the area above the cotyledonary node, the plant will be able to generate new growth from the auxiliary buds at the node. This new growth from these buds will be very similar to the original plant if it had not been damaged. Recovery will be good with little or no impact on final yield. If there are a mix of plants that will recover and several that are frosted and will not survive it is important to take stands counts from many areas of the field to determine the next step. We may find some areas that are hurt more than others, but the number I use to make decisions on replant is 100,000. If you have at least 100,000 plants an acre it is too good to justify the cost and time to replant. if replant is needed try to identify if you can fill in areas of the field, or if it is best to tear it up and start over. And just like corn, this crop has been stressed, so make sure you give it time to recover before you add any more to it with herbicide applications.