Swings in temperature may affect corn stands

The weather stations with the Commercial Agriculture Program – University of Missouri provide data showing soil temperatures. Local growers can find information at the Graves Chapple Farm, Hundley Whaley, or St. Joseph site which records soil temperatures. The warm temperatures provided an opportunity for many growers to plant corn last week.

The swings in temperature are of most concern with early planted corn. When soil temperatures rise and corn germinates, then followed by a cold temperatures and wet soil conditions, this change creates stress on corn plants. In fact, less stressful for seed to be placed in cold soil so it will slow germination than to have the swings in temperature where corn germinates then slows with cold soils.

In conditions where seed is germinated and soil temperatures drop, can result in erratic and uneven corn stands. Also, leaves may unfurl below the soil surface resulting in lack of emergence. If rains would continue to saturate soils, another risk is seedlings dying from lack of oxygen. All of this will depend on our future weather conditions.

Another risk is frost events. We have had issues with late frosts. However, if temperatures remain low, corn will grow slowly and will be able to handle a frost event as the growing point will be below the soil surface.

When corn planting starts again, be sure soil conditions are favorable. Early season damage from planting in wet soils can result in season yield losses.

For more information, contact Wayne Flanary at 660-446-3724 or Heather Benedict at 660-425-6434, Regional Agronomists, University of Missouri Extension.