This isn't a year one would suppose stress will cut into top yields. For some of you, it won't. There should be some bin-busting yield averages come fall. But that won't be the case for everyone.
It's been a cool and wet year, at least until recently, for most of the Corn Belt. Wrapped into that is a late start due to wet weather, ponding due to heavy June rains in pocket areas, delays due to weather that was too cool during grain fill, nitrogen shortages tied back to wet weather early, and a stretch of dry weather late in the grain-fill period.
No doubt, overall yield averages will be good. But don't expect to average 200 bushels in every field – unless you're in a garden spot. Remember that to get an average of 154 nationwide, or higher, someone has to have fields yielding considerably less than 200 bushels per acre to balance out.
One factor that seems to be showing up in some fields is one to two inches of empty cob at the tip. Scouting weekly reports indicated those ears started to set kernels in many cases, then aborted them. Why?
Dave Nanda, Director of Genetics and Technology with Seed Consultants, says there can be several reasons. In one field he's monitored, it's most likely a combination of two things – lack of soil moisture during the late grain fill period, coupled with the plants running out of nitrogen. He believes that's tied to a wet spring.
When stress sets in, the plant tries to maximize the kernels it knows it can produce, Nanda says. It doesn't know you're going to use its grain for anything but seed. The plant's mission is to procreate, and produce as many seeds that are viable as possible. If that means aborting tip kernels, the last ones pollinated, that's what it will do.
If you haven't checked your fields yet, you might take a look. See what tip fill is doing.