ESTIMATING YIELD COMPONENTS OF WHEAT FROM CALCULATED SOIL MOISTURE

Abstract

Yield components of a wheat crop, namely number of heads per unit area, number of kernels per head and 1000-kernel weight, were related to soil moisture estimated from a meteorological budgeting procedure using only standard climatic data. Several soil-moisture variables, such as moisture content in the root zone from jointing to heading, significantly affected all three yield components and thereby final grain yields. The calculated yield components did not give better estimates of grain yields than those obtained directly from soil-moisture variables, but they did provide a better insight into the relationships between soil moisture, other climatic variables and grain yields at each of the eight stations across Canada. The practical use of a soil-moisture climatology based on the established relationships between estimated soil moisture and yield components is discussed.