Drought and water management in Mediterranean vineyards

A large proportion of vineyards are located in regions with seasonal drought (e.g. Mediterranean type climates) where soil and atmospheric water deficits, together with high air temperatures, cause large constraints on yield and quality. The increasing demand for vineyard irrigation requires an improvement in the efficiency of water use. Deficit irrigation emerged as a potential strategy to allow crops to withstand mild water stress with little or no decrease in yield and a potential positive impact on berry quality. This, however, can vary with the variety. Understanding the physiological and molecular bases of grapevine responses to mild to moderate water deficits is fundamental to optimize the management of deficit irrigation and identify the most suitable varieties to those conditions. Deficit irrigation can also be managed to influence the concentration of berry secondary metabolites and profiles. The timing and intensity of irrigation influence berry metabolism, essentially secondary metabolites, and as a consequence wine sensory characteristics. This chapter discusses recent data related to metabolic changes and hormonal control of grape berry ripening under deficit irrigation and identify limitations in the interpretation of results.