Source: U.S. Department Of Agriculture, Bureau Of Agricultural Economics, Agricultural Statistics, 1937; 1939; 1941; 1942; 1950; And Crop Reporting Board, Crop Production, 1951 Annual Summary, December 1951; Crop Production, Mimeographed Release.
This NBER data series a01037g appears on the NBER website in Chapter 1 at http://www.nber.org/databases/macrohistory/contents/chapter01.html.
NBER Indicator: a01037g
Release: NBER Macrohistory Database
National Bureau of Economic Research, Wheat Crop, Yield Per Acre for United States [A0137GUSA254NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/A0137GUSA254NNBR, February 12, 2016.