Capacitance probes were tested in a young citrus orchard for irrigation water saving; Cumulative water received by the plot reached 334 mm and 398 mm for the first and second year period respectively (irrigation+useful rain). Irrigations were made in 521 interventions when the lowest dose of 1.05 mm was used and in 210 interventions when the highest dose of 2.6 mm was applied. Capacitance probes were giving values statistically different compared to the gravimetric method, but with, however, a meaningful interrelationship; A good correlation was then obtained between real values and reading from capacitance probes, a value of 16% showed by the C-probe is equivalent to 22%. The parameters of growth, trunk diameter microvariations probes (LVDT) and components of yield are well correlated with Soil moisture and Vapor Pressure Deficit (VPD). Treatment 1 (T1) was better in cold period (December, January and February), while Treatment 4 (T4) was more efficient from flowering (March) and developed deep roots (more than 50 cm). Leaf water potential and LVDT showed the sensitivity of T1 towards climate changes during high evaporative demand days. Analysis of soil moisture data showed that the field capacity was maintained at not more than 30 cm soil depth for T1, which developed very superficial roots (45% at only 10 cm). The number of roots was significantly different between treatments, T4 was distinguished by a greater concentration of roots (8843), compared to T1 (4104). After 27 months from plantation, the Yield showed a performance of 46 T/ha recorded for the dose of 2.1 mm, when the fruit size was 70% of Size 1-3; water saving was about 50% and valuated at 105 l/kg produced.
