This paper presents an introduction to agrometeorological crop yield forecasting (ACYF) methods. Such methods attempt to quantitatively assess the effect of weather vagaries on regional crop yields before harvest. The paper insists on the fact that all ACYF approaches are eventually calibrated against traditional yield statistics obtained through sampling procedures.
Three methods are covered: “descriptive” methods, regression methods and crop simulation methods. Descriptive methods simply classify weather conditions, according to one or several variables, to identify conventional thresholds separating groups of significantly different yields. Regression methods derive equations relating crop yield with weather variables. Finally, simulation methods, the most complex ones currently in use, attempt to analytically describe the physical and physiological impact of environment and management conditions on crop development, growth and yield.
In practice, methods will be selected based on their performance under a range of different conditions and their cost of implementation.