Irrigation management of ornamental shrubs under limited water resources

Agricultural water consumption accounts for 70% of the total available freshwater. Because the competition for this limited resource is increasing dramatically, optimising agricultural Water Use Efficiency (WUE) is a necessity. Achieving this target requires a shift from maximizing productivity per unit of land area to maximizing productivity per unit of water consumed. In commercial ornamental nursery production, irrigation is crucial to achieve the crop return, both in term of yield quantity and quality. Therefore, irrigation is often performed inefficiently since nurseries tend to over-irrigate plants. The difficulty in estimating the water requirements of ornamentals, the irrigation systems utilized, the large number of plant species/cultivars, and the production conditions (high-intensive cultivation methods, pot plants) are other variables that contribute to such inefficiency. Maximizing WUE, can be achieved by reducing water losses and promoting crop growth. New precision irrigation technologies and up-to-dated irrigation systems would enable growers to apply water and agrochemicals more efficiently. This paper focuses on the issue of irrigation water scheduling of ornamental shrubs under limited water resources. Specifically, we will review the means to enhance WUE in some Mediterranean ornamental shrubs production by applying deficit irrigation using plant ‘stress’ sensing measurements for irrigation scheduling.