The crop physiology of Helianthus tuberosus L.: A model oriented view

Information from the literature is discussed to define guidelines for a model of the growth and development of Helianthus tuberosus in non-limiting conditions. Dynamics of the leaf area index and the distribution of growth between structural growth and reserves (in stem, stolons and tubers) are the most crucial processes. Phenological events like stolonisation and tuberisation seem to be controlled mostly by plant growth. In this hypothesis, the main true developmental event is flower initiation. This last event is the main physiological shift determining the tuber yield and quality through change in assimilate distribution caused by saturation of aerial sinks. Directions are proposed for future research efforts aimed at improving the insight into crop physiology and gathering missing data for model parametrisation. Response of growth to water shortage, and nitrogen nutrition will be the next crucial questions to model the crop under field conditions.