An irrigation experiment was conducted during 5 years in two hedgerow olive orchards (C and L) cv. Arbequina in Central Spain. The control treatments (C1 and L1) were irrigated to maintain the “wetted bulb” near field capacity throughout the season. Three deficit-irrigation treatments were applied from shoot growth (April-May) until pit hardening (beginning of July) with water applications relative to control, C2, C3, C4 (50, 25, 0%) and L2, L3, L4 (40, 17, 0%), respectively. Treatments reverted to full irrigation after pit hardening. During the treatment period a series of phenological events occurs: bud break, shoot growth, flower differentiation, flowering, fruit set, fruit drop and pit hardening. Responses of vegetative growth, flowering, fruiting, fruit characteristics and production were evaluated through their relationships with midday stem water potential (Ψstem). Flowering was shown to be the most sensitive period to deficit irrigation and the major determinant of final production through reductions on fruit number and oil content. With high water during flowering (mean Ψstem before irrigation >−1.0 MPa) trees developed more nodes, leaves, fertile inflorescences and fruits per inflorescence with consequent high production (1278 kg oil ha⁻¹). Oil production was significantly reduced (64% of maximum) when Ψstem was allowed to fall below −1.5 MPa at flowering and was halved at −1.7 MPa, reducing water productivity from 0.26 to 0.21 kg oil m⁻³. In contrast, Ψstem could be reduced to −1.8 MPa after flowering until pit hardening without effects on fruit drop, fruit size or oil content. Fruit drop increased when Ψstem from flowering until pit hardening was below −2.71 MPa. Fruit oil content at harvest was strongly related with fruit dry weight at pit hardening. Vegetative growth occurred continuously during spring, although mainly during flowering, and could not be reduced by deficit irrigation without reducing production. The results are advantageous to irrigation management in this and similar climatic regions where Spring is a critical period for olive production due to variable temperature, rainfall and crop water demand. They establish the high thresholds of Ψstem required to guide irrigation management during Spring without yield loss, and the substantial resulting loss when this threshold is exceeded. They also reveal that deficit irrigation strategies cannot be used in Spring to control canopy size in hedgerow orchard without serious impact on yield.

在5年中在两个树篱橄榄果园（C和L）中进行了灌溉实验。Arbequina在西班牙中部。整个季节都进行了对照处理（C1和L1）以保持“湿球”接近田间生产能力。相对于对照C2，C3，C4（50％，25％，0％）和L2，L3，L4（3），从枝条生长（4月至5月）到坑硬化（7月初）开始施以三种亏水处理。 40、17、0％）。坑硬化后，处理方法恢复为完全灌溉。在治疗期间，发生了一系列的物候事件：芽断裂，芽生长，花分化，开花，坐果，落果和凹坑硬化。营养生长，开花，结果，通过与中午茎水势（Ψstem）的关系来评估果实的特性和产量。通过减少果实数量和含油量，开花是对缺水灌溉最敏感的时期，也是决定最终产量的主要决定因素。开花期水高（灌溉前的平均茎> -1.0 MPa），树木长出更多的节，叶，肥沃的花序和果实，因此产量高（1278 kg油/公顷）。^-1）。当开花时使Ψ降低到-1.5 MPa以下并在-1.7 MPa减半时，产油量显着减少（占最大值的64％），水生产率从0.26千克油米^-3降低。相反，开花后直至茎硬化，hard茎可以降低至-1.8 MPa，而对落果量，果实大小或含油量没有影响。当从开花到硬核硬化的茎干低于-2.71 MPa时，水果滴增加。收获时的果油含量与窖硬化时的果干重量密切相关。营养生长在春季持续发生，尽管主要在开花期，并且如果不减少产量就不能通过亏缺灌溉来减少。由于温度，降雨量和作物需水量的变化，春季是橄榄生产的关键时期，这一结果有利于该地区和类似气候地区的灌溉管理。他们确定了指导春季灌溉管理而不会造成产量损失的较高的茎干阈值，超过此阈值将导致大量损失。他们还揭示了在春季春季不能使用亏缺灌溉策略来控制树篱果园的冠层大小，而不会严重影响产量。