Hard red winter wheat cash basis bids in the southern US Plains on Thursday held steady as futures moved lower, pressured by strong crop prospects for the US Plains, merchandisers said. Crop scouts on the final day of an annual tour of Kansas estimated the wheat yield at 48.6 bushels per acre (bpa) in the country's top producing state. That is above the five-year crop tour average of 39.3 bpa and the US Agriculture Department's estimate of last year's harvest of 37.0 bpa. Protein premiums for railcar wheat to and through Kansas City on Wednesday were unchanged, according to the latest CME Group data. At 12:11 pm CDT (1711 GMT), K.C. July wheat was down 4 1/4 cents per bushel at $4.39-3/4.