Growth Response of a Chrysanthemum Crop to the Environment. II. A Mathematical Analysis Relating Photosynthesis and Growth

Abstract

Vegetative crops of chrysanthemum were grown for 5 weeks in three replicate daylit assimilation chambers. Weekly harvests were made from each crop for growth analysis, and on seven occasions during the 5-week period continuous measurements of the net CO₂ exchange rate of each crop were made over a 24 h period. A semi-empirical model for canopy photosynthesis was fitted to these data. The photosynthesis model was then incorporated into a simple, dynamic growth model. Using fitted values of the canopy photosynthesis parameters, the daily total radiation integrals, and the experimentally observed relationship between the leaf area index and crop dry matter per unit ground area, the crop growth model was used to simulate growth over the 5-week period. The predicted and measured crop dry weights were in close agreement over the whole period.