OPTIMAL TEMPERATURE REGIMES FOR A GREENHOUSE CROP WITH A CARBOHYDRATEPOOL - A MODELING STUDY

A simple crop model with two state variables, namely structural biomas s and carbohydrate pool, was used to explore the effect of alternative temperature regimes on greenhouse crop production, Assuming a repeate d environmental cycle, certain qualitative predictions could be made. (1) The smaller the plants and the higher the light integral and CO2 e nrichment, the higher are the temperatures which lead to maximum produ ction. (2) Day temperatures higher than night temperatures usually lea d to higher production. On winter days, however, an inverse temperatur e regime may result in energy saving without loss of production. (3) T emperature variations may often be tolerated, provided that the mean t emperature (temperature integral) is maintained at the level appropria te for maximum production. A limited amount of published experimental data was used to fit the model, leading to a satisfactory agreement.