Dry Matter Partitioning in Tomato: Validation of a Dynamic Simulation Model

Abstract

A model for dynamic simulation of dry matter distribution between reproductive and vegetative plant parts and the distribution among individual fruit trusses in glasshouse tomato, is validated. The model is part of the crop growth model TOMSIM and is based on the hypothesis that dry matter distribution is regulated by the sink strengths of the plant organs, quantified by their potential growth rates, i.e. the growth rates at non-limiting assimilate supply. Within the plant, individual fruit trusses are distinguished and sink strength of a truss is described as a function of its development stage. Truss development rate is a function of temperature only. The same potential growth curve, proportional to the number of fruits per truss, is adopted for all trusses. In a simple version of the model, vegetative plant parts are lumped together as one sink with a constant sink strength. In a more detailed version, vegetative sink strength is calculated as the sum of sink strengths of vegetative units (three leaves and stem internodes between two trusses).