Fears are rising that grain crops in the core of the U.S. Corn Belt - the top corn-producing region in the world - will suffer big losses that are already causing farmers to plow up fields in other regions of the belt, agronomists and traders said last week.
Iowa and Illinois - which produce about a third of all U.S. corn and soybeans -- are threatened by the harshest heat wave in more than half a century. Blistering temperatures, combined with little rain, are stressing corn during pollination, the key growth stage.
"By Sunday or Monday if we don't get rain here we will be losing anywhere between 7 to 9 percent of our yield potential," said Roger Elmore, corn agronomist at Iowa State University in Ames, Iowa. "If it drags on into next week, it is going to be worse."
Drought conditions, which intensified during the past week across the central United States, have caused irrevocable damage to crops in Missouri, Indiana and even southern Illinois, where farmers are cutting stunted corn for silage, a low-grade feed for cattle.
"Next week is critical for Iowa," said Elmore. "Even the crops on good soils are going to start showing a lot of stress going into next week if we don't have rains soon."
Mike Hutjens, University of Illinois professor of animal sciences, said corn plants, especially in the southern third of the state, are showing irremediable stress from the heat and drought.
"Corn plants are firing from the roots up the stalk of the corn plant," he said, meaning stalks are drying out. "Some corn has tasseled, which may not pollinate, resulting in barren corn stalks" with no ears of corn.
Agronomists said calls by farmers for crop insurance claims continued to rise this week, and the worst is far from over for both farmers and consumers, as well as corn processors and exporters worried about supplies and soaring grain prices.
The region's soybean crop is also stressed, but was planted a month behind corn. Its key growth stage comes in August.
"Livestock producers may be able to purchase drought-stress corn locally, as it has little value for grain or hog producers," Hutjens said. "Like livestock producers in the southwest areas of the United States last summer, dairy managers are asking what will be available and affordable for their dairy cattle this fall and winter? Drought-stress corn silage may be an alternative locally. Consumers will share in the cost of drought-stressed corn this summer as corn yields may be quite low, raising food prices and ethanol costs."