Chicago agricultural commodity futures dropped Thursday on export cancellation and speculation that warmer and drier weather will boost planting this week. The most active corn contract for July delivery fell 12 U.S. cents, or 2.31 percent, to 5.07 dollars per bushel. July wheat lost 14.25 cents, or 1.98 percent, to 7.0725 dollars per bushel. July soybeans fell 51.75 cents, or 3.42 percent, to close at 14.61 dollars per bushel. May 1 trading day marked the introduction of new daily price limits for grain futures at the Chicago Mercantile Exchange. Soybeans kicked off the new month by tumbling over half of the new 1.00-dollar trading limit for soybeans. The selling was partly triggered by U.S. Department of Agriculture's report of a small net-cancellation in last week's export sales, but commercial selling and overall nervousness about soybean prices near the 15-dollar level were the real culprits. Corn also fell on speculation that warmer weather will lead to rising supplies of the crops. The central and southern U.S. Corn Belt will be mostly dry until at least May 8, and higher temperatures early next week will help dry out wet soils so farmers can seed crops, according to weather forecast.