Farmers Worry Heatwave and Wind Will Negatively Impact the Corn Crop

By Sheila Brummer

Farmers worry a heatwave and wind will negatively impact the corn crop.

Hot and humid air is forecast to invade Iowa this weekend and could stick around through the middle of next week.

The National Weather Service in Des Moines says many areas of Iowa could see temperatures in the 90s with heat indices topping 100 degrees. An Excessive Heat Watch was issued for more than half of the state on Friday, Aug. 18.

While conditions might be uncomfortable for humans and animals alike, they could also pose a problem for corn producers.

Dave Rossman, a longtime farmer from Hartley, is seeing a mixed bag this season when it comes to the weather.

"We're supposed to be in the upper 90s and windy, so there's going to be a lot of evapotranspiration, but we can't do anything about it. So, we just sit back and watch and think about yield estimates. How much you may or may not want to sell. But we can't change it. We can't cause the rain. So just watch and watch and wait and take it. Take what you get."

IPR News contacted Iowa State University Extension and Outreach Field Agronomist Leah Ten Napel for more information about evapotranspiration.

In a released statement, Ten Napel stated, "Evapotranspiration is the combination of soil moisture loss (evaporation) and crop water loss (transpiration). High wind speed, high temperatures, low relative humidity and adequate soil moisture increase the rate of evapotranspiration. Higher corn yields require more inches of moisture for evapotranspiration. The lack of adequate moisture is a yield-limiting factor in corn plants."

A recent crop report from the U.S. Department of Agriculture shows both corn and soybeans are rated 58% good to excellent.