While planting season is kicking off, there is caution around cold temperature injury and “chilling imbibition” in corn.
Every season there is a lowest corn yielding field for each farm. Sixty to seventy percent of the time the reason this is the poorest yielding can be traced back to a cold rain occurring after planting.
Corn seed goes in the ground dry at 10.5-11.5% moisture. For germination to begin, the seed needs 30% of its weight in water and will start absorbing moisture as soon as it is in the ground. If there is already enough moisture in the soil, germination could take place within twelve to twenty-four hours from planting. This existing moisture could be warm, but during this time of year it is likely to be as low as forty-five degrees because of common cold fronts moving in and out. When a seed absorbs this cold moisture, the cells will start to elongate but will rupture due to the rigidity that occurs from the cold-water intake. This is known as chilling imbibition injury. The seed will then die before producing a shoot and reaching the surface of the soil. It won’t just be a small plant; it won’t come up at all.
Use caution when a cold front is coming in with a cool rain. A good rule of thumb is to be done planting twelve hours before an expected rainfall. Chilling imbibition does happen, but there are ways to prevent it. Reach out to your agronomist for tips to avoid this kind of crop injury.