Cash basis bids for hard red winter (HRW) wheat in the southern US Plains on Tuesday were steady as futures followed corn and soybean contracts lower ahead of record-large harvest outlook, merchandisers said. Winter wheat planting is underway in parts of the country as combines pick corn, with soybeans to be harvested in a few weeks. The US Department of Agriculture late Monday said the US winter wheat crop was 6 percent planted, compared with the five-year average of 7 percent. Protein premiums for wheat shipped to and through Kansas City held steady on Monday.