Jarrod Miller, Extension Educator, Somerset County
A great yield requires the whole season, from planting all the way to harvest. Fields of corn may have great stands from adequate spring and early summer conditions, but still suffer during pollination.
Pollination is a sensitive time for a corn plant, and stressful conditions can drastically reduce kernel set. A corn field may take 7-14 days to shed pollen from the tassels and fertilize the emerging silk. Heat stress (>86F) may limit pollen shed reducing fertilization. Heat or drought stress may also slow silk emergence, so that it misses pollen shed. Since silk emergence starts at the base of the ear and works its way up, the tip is the most likely place to miss pollination and have poor kernel set. Variable temperatures, moisture or insect damage over these two weeks may lead to poor kernel set across the whole ear.
Rather than get a surprise at harvest, it is a good idea to scout historically droughty fields right now. This may give you a heads up as to why yields were lower than expected. Scouting now may reveal the difference between heat stress or June bugs clipping silk, which won’t be as apparent in September. This will allow for better planning next year, to minimize as many yield risks as possible.
Other reading on fertilization and recognizing abnormal ears:
https://www.agry.purdue.edu/ext/corn/news/timeless/silks.html
