Limitations of the Farquhar–von Caemmerer–Berry Model in Estimating the Maximum Electron Transport Rate: Evidence from Four C3 Species

The study evaluates the accuracy of two FvCB model sub-models (I and II) in estimating the maximum electron transport rate for CO2 assimilation (JA-max) by comparing estimated values with observed maximum electron transport rates (Jf-max) in four C3 species: Triticum aestivum L., Silphium perfoliatum L., Lolium perenne L., and Trifolium pratense L. Significant discrepancies were found between JA-max estimates from sub-model I and observed Jf-max values for T. aestivum, S. perfoliatum, and T. pratense (p < 0.05), with sub-model I overestimating JA-max for T. aestivum. Sub-model II consistently produced higher JA-max estimates than sub-model I. This study highlights limitations in the FvCB sub-models, particularly their tendency to overestimate JA-max when accounting for electron consumption by photorespiration (JO), nitrate reduction (JNit), and the Mehler reaction (JMAP). An alternative empirical model provided more accurate Jf-max estimates, suggesting the need for improved approaches to model photosynthetic electron transport. These findings have important implications for crop yield prediction, ecological modeling, and climate change adaptation strategies, emphasizing the need for more accurate estimation methods in plant physiology research.