摘要
Due to the global expansion of irrigated areas and the limited availability of irrigation water, it is necessary to optimize water use in order to maximize crop yields under water deficit conditions. To evaluate the yield response of two processing tomato hybrids (Ercole and Genius) grown under different irrigation treatments, a field trial was conducted during the 2008 growing season in Southern Italy. Three irrigation treatments were used: the restitution of 70% of maximum evapotranspiration (ETc) both under "Deficit Irrigation" (70DI) and "Partial Root-zone Drying" (70PRD) strategies; full irrigated (FI: 100% ETc). The two water deficit irrigation treatments (DI and PRD) showed stomatal conductance values lower than FI treatment and saved a substantial amount of water maintaining reasonable marketable yield. Moreover, PRD strategy showed slightly higher "Water Use Efficiency" (WUE) values than DI. Finally, "yield response factor" (Ky) showed always values less than unity, indicating the possibility to adopt, within certain limited condition, both DI and PRD in field-grown processing tomato cultivated in Southern Italy. In conclusion, in our experimental conditions, deficit irrigation practices seem to be acceptable relatively to processing tomato yield aspects and Ky could be promoted as a useful indicator for irrigation in water deficit conditions.