Deficit irrigation strategies: Use of stress physiology knowledge to increase water use efficency in tomato and potato

Abstract

Many vegetables, including tomato and potato, have high water requirements, so that supplemental irrigation is necessary for successful production. The predictions are that the demand for irrigation will increase considerably in years to come to alleviate the consequences of climate change and more frequent and severe droughts. Water is expected to become the main limiting factor in agricultural production. However, as a consequence of global climate changes and environmental pollution, water available for agriculture is often reduced. Emphasis therefore must be placed on crop physiology and crop management under dry conditions in order to make plants more efficient water users. Recent results have demonstrated that regulated deficit irrigation (RDI) and alternate partial root drying (ARD) are new deficit irrigation strategies which may decrease demand for agricultural use of water. The application of these techniques to crops such as tomato and potato has demonstrated benefits in terms of improved wateruse efficiency and a stable yield, in addition to an increased yield quality. Both methods are developed on what is known on plant responses to drought stress and to the mechanism of root-to-shoot drought stress signalling. In this paper we review the research on the responses of tomato and potato to ARD and RDI irrigation strategies, with special emphasis on drought stress signalling mechanisms. Comparison of the beneficial effects of ARD and RDI were done with the aim to suggest which of these strategies may be used to get maximum tomato and potato water productivity and economic returns in dry environments.