BASES FOR THE PREDICTION OF CORN YIELDS.

摘要: Accurate crop yield estimates at the earliest possible date are of major importance to producers, handlers, warehousers, railroads, and consumers, whose plans operations depend upon knowledge present future stocks their commodity. Past attempts prediction have been largely two types. The Crop Reporting Board U. S. Department Agriculture has prepared its reports from questionnaires sent large numbers correspondents. average many individual estimates, corrected on basis past experience, been, probably still is, most reliable method available. It is obvious, however, that supplementary, objective measurements would greatly increase value estimates. second used in attempted supply predictions Weather Bureau data, published correlations between various climatic factors, particularly seasonal rainfall temperatures, yields (5). Statistical studies weather records not proved be a promising for predictions. Consequently CropWeather-Yield Project was set up by Agricultural Marketing Service, cooperating with State Experiment Stations, determine more specifically physiological effects climate plant development. This project intended "To improve regular forecasts discovering applying relationships include an forecasting relationship structural counts, measurements, phenological yields, either separately or factors." work corn started 1938 centered Iowa Station Statistics, Botany Plant Pathology, Agronomy other Sections cooperating. Detailed development microas well as macroclimate were made station plots Ames 1938,1939 1940. results these summarized Bair (2, 3). Less detailed corn-belt Stations 1939 1940, part which Keller (7).