Bob Nielsen has become well known for the 'shake test.' No, Bob doesn't dance. But he makes young ears of corn dance when he unrolls the husks and gets down to the cob, ovules and silks. The whole idea is to see if the ear pollinated. In some cases, it may be to determine how well it pollinated.
Some spots within fields won't have ears this year. But for those that do, now is a good time to see if the extreme heat during pollination affected the process, or if the ear was pollinated successfully. Nielsen, Purdue University Extension educator, says the test is simple but yet revealing about what is happening or has happened in your cornfield.
To do the test, simply pick representative ears. Peel back the husk leaves carefully. If you're too aggressive you may rub off the silks if they're still attached to the ear, and get a false reading. Once you have the leaves off, and are sown to the ear and silks, hold the ear at arm's length. Make it dance by shaking it.
You're hoping silks fall off. If they do, that means that the ovules those silks were attached to pollinated. If the silks stay attached, the ear isn't yet pollinated. If there is still pollen in the field, fertilization could still occur. However, silks become unreceptive to pollen rather quickly, Nielsen says.
Here's why the test works. A single pollen grain travels down the tube that is the silk. Each silk is attached to a single ovule on the ear. If fertilization occurs, within a few hours the silk near the base of the ear will begin to dry up. Then it will detach itself from the now early-formed kernel. If you shake the ear, those silks that fall off mean they did their job and fertilized ovules. Kernels will begin to form there.