Modelling water relations of horticultural crops: a review

This paper introduces the basic principles of plant water relations modelling, and reviews some examples of application to horticultural crops. Water relations models are essential components of all crop models because of the critical role that water status has in determining growth, productivity and produce quality. The importance of water to horticultural crops is particularly great because most horticultural produce is sold by weight, with water being the major component, so there is often a marked premium in ensuring that water content is optimised, often through precise control of irrigation. After providing a theoretical background to plant water relations models, the main models for describing and predicting both water flow through plants, and the processes of water uptake from the soil and evaporative loss to the atmosphere are described. The final section then brings together this information in some models that attempt to show how models can either provide insight into the nature of the interactions between the various physiological processes involved in the control of plant water status or which can be used to investigate the optimal plant responses in water limited situations. (C) 1998 Elsevier Science B.V.