June 22, 2011
U.S. Corn Plant Populations Impacted by Wet Conditions
Even though the corn may not have been drowned out, extended periods of saturated soils can result in lower plant populations and that is exactly what is being reported. A lack of oxygen in the root zone and fungal diseases in the soil can significantly reduce the plant populations. In many areas of the Midwest, an optimum corn plant population is probably in the range of low 30,000 plants per acre. If as few as one or two thousand plants per acre succumb to the saturated conditions, the eventual yield will be negatively impacted.
Even if the corn crop in a certain area is not drowned out by standing water, the fact that the soils stay saturated for an extended period of time can result in a loss of corn plants. The losses may not be severe enough to justify replanting, but the resulting lower plant populations can result in lower yields. Some of this year's corn crop was planted under less than ideal conditions, which could make the plants even more susceptible to adverse conditions.
If corn plants are missing within a row, the neighbor plants can produce a somewhat larger ear and this is call ear flexing. The larger neighboring ears can partially compensate for that lost ears, but ear flexing cannot entirely make up for hundreds or thousands of ears missing in an acre.