b

Abstract 2 The aim of this study was to establish threshold TGR and MDS values which could be 3 used in regulated deficit irrigation in future work. Three irrigation treatments were 4 performed during three seasons in a 37 year-old table olive orchard in Seville (Spain). 5 Control treatment was irrigated with 125 % of the crop evapotranspiration. Regulated 6 deficit irrigation (RDI) treatments were performed according to the phenological stage 7 of the trees and different water stress levels. RDI trees were irrigated only when the 8 threshold values of water stress level was reached. Water stress conditions were applied 9 during the massive pit hardening period (phase II) or during this period and the shoot-10 flowering period (phase I). The water stress level was performed with the trunk growth 11 rate (TGR) during phase I and recovery and maximum daily shrinkage signal (MDS 12 signal) during phase II. Both parameters were calculated as relative values of the 13 Control trees. TGR threshold values varied from equal to Control or 0.25 m day-1 less 14 than Control. MDS signal (ratio between MDS in RDI vs MDS Control) threshold 15 values varied from 0.5 to 0.75. This scheduled changed the amount of applied water 1