Bob Nielsen is usually a busy man this time of year. Somewhere in Indiana, something goes a bit crazy with pollination and fertilization and kernel set almost every year. Sometimes it may be just in a few fields. This time it may be statewide! The Purdue University corn specialist will be drawing on roughly 30 years of experience across a wide range of weather conditions to provide people with as any answers as he can about what to expect. Unfortunately, unless you have irrigation, there's not much you can do, other than to get a better handle on how much corn you may or may not have to store and/or contract this fall.
First, Nielsen addresses the pollen, or male part of the plant. It comes from the tassels. There's typically an ample supply of pollen. Usually if there is a failure, it's not because there is enough pollen. Pollination is the act of the release of the pollen- Fertilization is the act of the pollen grain fertilizing an ovule, inside a corn silk.
There are two important things in play related to pollen shed. First, pollen can survive high temperatures. However, temperatures at 100 degrees or higher can kill pollen. There has been at least one 100 degree day reported at Indianapolis, that being July 21.
The second is that pollen will not shed if it's raining, or during a heavy dew. The dews are unusually heavy in some areas because the dew point is high, at 80 degrees, according to Ken Scheeringa, of the state climatologist's office.
However, these two issues aside, if corn doesn't pollinate correctly, it likely won't be due to death or lack of pollen. That's because pollen release occurs over several days. If pollen should be destroyed by heat one day, there can still be pollen release the next day.
So while this heat wave coupled with the high humidity is producing some unusual conditions, failure to get kernel set because of a problem with the tassels and pollen is not likely.