A dynamic model system to couple the organ length and mass dynamics specified for spring barley (Hordeum vulgare L.)

An important goal in developing functional-structural plant models (FSPMs) is a reliable and adequate description of the inherent interactions between processes controlling plant growth and formation of plant architecture. Several architectural models have been introduced for specific crops using temperature-driven descriptive models based on the phyllochron / plastochron philosophy (Dornbusch et al., 2007; Drouet, 2003; Evers et al., 2005; Fournier et al., 2003; Prévot et al., 1991; Watanabe et al., 2005). In order to couple those architectural models to process models, which lastly compute the amount of mass assimilated by the photosynthetically active organs, an interface between mass dynamics and the formation and growth of new organs needs to be developed. Fournier et al. (2005) introduced a model to describe the length dynamics of leaf blades and leaf sheaths of wheat (Triticum aestivum L.). Here we propose an extension of this model to describe the length dynamics coupled with the corresponding mass dynamics of barley (Hordeum vulgare L.) organs (blades, sheaths and internodes) based on experimental data. The proposed model includes a set of coupled ordinary differential equations (ODEs). The model performance is demonstrated by simulation studies.