DES MOINES, Iowa (AP) – Authorities say a brutally hot July and a relatively dry summer have caused a moderate to severe drought in about a third of Iowa and have lowered expectations for the state’s corn crop. Crop yield predictions are down, and some lawns, particularly in southeast Iowa, have yellowed without adequate rain. The U.S. Department of Agriculture predicted early last month that Iowa would average 177 bushels of corn per acre, down from 182 bushels in 2009 but higher than the 165 bushels per acre last year. But the continued lack of rain has prompted some private forecasters to drop the projection for Iowa’s corn yields to as low as 164 bushels per acre.