High Day Temperatures and Corn Pollination

Chad Lee, Extension Agronomist, University of Kentucky

Corn pollen drop is
occurring in many fields. 

Much of the corn in the state is going through pollination right as daytime temperatures are the highest for the season. Fortunately, most pollen drop occurs earlier in the morning and some occurs later in the evening. Soon after pollen comes into contact with silks, it begins pollen tube growth in those silks. As long as morning temperatures stay in the low 70's, pollination should occur without much trouble. Last year, morning temperatures were in excess of 90 degrees, relative humidity was low, the soils were extremely dry and the corn was under severe drought stress. This year, humidity is accompanying the hotter temperatures. The higher humidity will help the viability of the pollen grains.



Although our weather is humid, most of the state has experienced limited rainfall over the past week or so. Thankfully, most soils were at field capacity before this hotter, drier period. Corn is under much less stress this season than it was last year during pollination. So, for now, pollination and corn development should proceed well. If we get adequate rain in the next few days, pollination and yield potential will be excellent. There are a couple of pockets where corn is under drought stress and yield potential has already been damaged.

In the short-term, pollination and corn development should progress just fine. However, for the first time this year, many of us are now watching the weather forecast to see when it will rain, rather than when it will stop.

Resources on Pollination
Corn Pollination - Ohio State
Heat and Drought Stress on Pollination - Purdue