The condition of U.S. corn crops was unchanged last week as cooler weather eased plant stress from the worst drought in half a century.

About 23 percent of the corn in the week ended Sunday was rated good or excellent for a third straight week, the U.S. Department of Agriculture said Monday. Soybeans were rated 31 percent good or excellent, up from 30 percent a week earlier, according to the USDA.

"The weather has stabilized and maybe benefited a few areas" in the main soybean-growing region, said Jamey Kohake, the branch manager at Paragon Investments in Silver Lake, Kan. "The reports are pretty much done. Now, people are going to start focusing on the harvest."

Corn farmers have harvested 4 percent of the crop, up from 1 percent a year earlier.