A number of curve fitting methods were evaluated for their applicability in modeling plant canopy photosynthetic dynamics. Non-Parametric and Non-Linear models were applied to long term dynamics in photosynthesis and response surfaces relating photosynthesis to crop age and light intensity. All models performed well, but computational details in the non-linear least squares algorithm made the simpler, non-parametric model forms more attractive. Applications of these modeling techniques are addressed in the context biomass production research and in the assessment of air revitalization capacity for bioregenerative life support. These techniques are especially useful in the modeling of crops exhibiting complicated growth profiles.