Effect of irrigation regimes and foliar nutrition on flower development and water productivity of olive (Olea europaea cv. ‘Shengeh’)

Background: Despite the high productivity in temperate regions, the olive has a poor yield, under environmental stress due to the inappropriate flower bud development and increment of staminate flowers. Objectives: In this experiment, the effect of irrigation regimes and foliar nutrition with nitrogen, calcium, zinc and boron on this complication was investigated. Methods: Two experimental factors contained irrigation regimes - irrigation to 50 percent of maximum allowable depletion (MAD) (Control) (I50) – increasing the irrigation to 25 percent of MAD during flower initiation (I25init) - increasing the irrigation to 25 percent of MAD during olive flower induction (I25ind), and I25init + I25ind; and foliar nutrition - without treatment (control), and foliar nutrition with 2% urea fertilizer; 2% Ca-EDTA chelate, 9.5% Ca; 0.2 % Zn-EDTA chelate and 0.2 % boric acid, during flower initiation (FNinit), flower induction (FNind) and FNinit + FNind. Results: The results indicated that the increment of irrigation water to 25 percent of MAD during flower initiation along with foliar nutrition at both times had the highest influence on the increment of perfect flowers with 3-4 developed ovules. This treatment had the highest water productivity and fruit oil content and can be recommended for olive groves under drought stress.