A model of canopy irradiance in relation to changing leaf area in a phytotron-grown snap bean (Phaseolus vulgaris L.) Crop

Simple exponential decay models were used to describe the variation in irradiance profiles within a snap bean (Phaseolus vulgaris L.) canopy over a 33-day period of canopy development. The extinction coefficients of these models were varied over time as a function of changing canopy leaf area; nonlinear least-squares procedures were used to estimate parameter values. The resultant model response surfaces depict the changes in canopy irradiance that accompany canopy maturation and illustrate the dynamic nature of canopy closure. A criterion index is defined to aid in assessing the applicability of these models for use in whole-plant simulation models, and an evaluation of these models is given based on this index, their predictive accuracy, and the utility for use within varying modeling frameworks. © 1984 Swets & Zeitlinger.

Duke Scholars

Author James F. Reynolds Environmental Sciences and Policy