Short husks and exposed ear tips were common this year. As a result, the exposed kernels were sometimes the target of bird feeding, insect damage and mold growth. This phenomenon has been occasionally present in the past but it seemed to be more prevalent this year in larger areas of the Corn Belt.
To fully understand why this happens, one must first understand how the ear of the corn plant develops. Ear development begins in the V6-V7, knee high stage of plant growth. Environmental conditions at this stage not only determine the potential for the number of rows of kernels but also, to some extent, whether or not an ear will continue to develop or abort. The potential length of the ear is determined after that in the V16-V17 stage just before pollination. What happens between these two stages is critical in determining if there will be “normal” ear development or if there will be the short husk phenomenon, or if other yield reductions will result.
The short husk ears that occurred this year resulted from favorable growing conditions at the knee-high stage followed by a period of drought and/or heat stress later on with favorable conditions after that. The ears basically started to develop normally, and then a period of stress stopped the growth of the whole plant, including the ear. When favorable conditions returned, the cob resumed growing but the husks did not. The cob then grew beyond the husks, exposing as much as a third to half of the grain.
There does not seem to be a varietal or a management difference in the expression of this phenomenon. Other stresses from nutrient deficiencies and/or herbicide damage do not seem to cause this effect. Pre-tassel root injury from drought or insect damage does contribute to similar expression.
To minimize this in the future, remember that SmartStax hybrids provide the best root protection from insect damage. Keeping the roots intact and healthy could keep the plant healthy and growing which could minimize the probability of re-occurrence. DroughtGard hybrids can also help by reducing the effects of a midseason drought stress. Just keep in mind that this is not a varietal issue. Stick with the plan of planting 3-4 hybrids positioned for your fields with different maturities and genetic backgrounds. Spreading your risk is always a best practice management decision for moving forward to a better 2020.
The top ear in the photo shows normal ear and husk development. The bottom two ears
show shortened husks with the cob tip and kernels exposed to the elements.