Predicting Corn Yield Under Limited Irrigation Using Plant Height

Abstract

ABSTRACT A4-year irrigation study was conducted with corn (Zea mays L.) in which plant height was monitored under different moisture levels provided by a line source sprinkler irrigation system. Evapotranspiration computed by the water balance method was used to quantitatively describe the different moisture levels. The data show that corn plant height is a good indicator to characterize plant water stress, and a simple method is presented to assess corn water requirement, utilizing plant height and growing degree days. This method is based on the linear relationships found between plant height and growing degree days, relative evapotranspiration and relative plant height, and relative yield and relative evapotranspiration. This method provides a quick, simple way to predict yield reduction as a result of water management practices. Limitations of the method are also discussed. Plant height was also predicted using the functional relationships in an irrigation scheduling model. The model and measured plant height were the same throughout the growing season for plants under both non-soil-moisture and severe soil-moisture-stress conditions. Field measurements of plant height can be used to verify that the irrigation scheduling model is accurately predicting the effects of soil-moisture-stress on corn growth and yield.