ST. LOUIS (AP) -- The U.S. Agriculture Department is predicting what could be the lowest average corn yield in more than 15 years as the worst drought in decades scorches major farm states.

Garry Niemeyer farms 1,200 acres of corn and 800 acres of soybeans near Auburn, Ill. He says he's "totally stunned" to have corn with green stalks and leaves after going through weeks of 105-degree temperatures.

Niemeyer says his corn yield normally is about 190 bushels per acre. But he says he'll be "thrilled to death" to get 110 this year.

Illinois State University agriculture economics professor Rick Whitacre says consumers may see modest price increases at grocery stores. He says the biggest price jump is likely to be a 4 to 6 percent increase for beef and pork.