Soybean futures slid for a third consecutive session on the Chicago Board of Trade (CBOT) Thursday, diving 2 percent to their lowest since mid-August, as a widely watched crop tour reported bumper prospects across the U.S. Midwest.Corn lost ground for a fourth session in a row and wheat was flat, amid expectations for huge global grain supplies.The annual four-day Pro Farmer Midwest Crop Tour observed on Thursday soybean crop prospects in southern Minnesota that were above average, and in line with last year.Late on Wednesday, the tour reported above-average soybean pod counts in Illinois and the western portion of Iowa.“I think the beans have a long way to go on the downside,” said Bill Biedermann, manager of Allendale Inc.’s Crystal Lake, Ill., brokerage branch.