Super High Density Olive Orchard Research Articles

Influence of the rehydration period on yield quality and harvest performance in Manzanilla de Sevilla super high-density olive orchards

AbstractSuper-high density olive orchards may increase profitability for table olive producers. However, water needs and fruit damage could limit their viability. Deficit irrigation scheduling would reduce the amount of water required, but rehydration before harvest is extremely important. The aim of this work was to compare a typical deficit farm management model with a regulated deficit irrigation one based on the plant water status. The experiment was carried out during three seasons in a three years-old (4 × 1.5 m) commercial table olive orchard. In both irrigation scheduling plots, seasonal amount of applied water was similar. Irrigation treatments were: common farm management (CFM), an almost constant rate of irrigation, and Regulated deficit (RDI) based on midday shaded water potential. Vegetative measurements suggested that RDI increased the external surface of the hedge, and this was related with greater yield in this treatment. Significant differences were found in of fruit size at harvest in some seasons, with larger fruits in RDI compared to CFM. However, fruit damage occurred during mechanical harvest in both irrigation managements, despite the higher skin firmness in RDI, and shows the need to carry out postharvest treatments to improve the quality of the final product. Accurate control of the tree water status would allow optimizing the amount of water available for table olive orchards.

Super high-density olive orchard system affects the main olive crop pests

The increasing use of the super high-density (SHD) olive orchard system requires a careful assessment of its potential impact on the main olive pests. The purpose of this study is to evaluate the SHD effect on Bactrocera oleae and other harmful phytophagous species by assessing damages caused by each pest. For three years, in three different sites in Tuscany established with Italian selection or Spanish Arbequina cultivars, the SHD management system was compared to an adjacent traditional olive orchard system in which the same soil and phytosanitary management were applied. Samplings of twigs and fruits from spring to fall together with adult monitoring of B. oleae, Prays oleae, and Palpita vitrealis by pheromone traps were used to determine infestation percentages and insects’ population dynamics. Bactrocera oleae, Liothrips oleae, and Euphillura olivina were negatively affected by the SHD olive orchard system, while P. vitrealis and Otiorhynchus cribricollis were favoured by this management. Bactrocera oleae total infestation was reduced to almost 50% in the SHD system. In contrast, Palpita vitrealis showed high infestation levels in more vigorous cultivars. Further studies are required for a complete evaluation of the impact of SHD management on olive pests.

Reducing environmental exposure to PPPs in super-high density olive orchards using UAV sprayers.

The increasing demand for optimizing the use of agricultural resources will require the adoption of cutting-edge technologies and precision farming management. Unmanned Aerial Vehicle (UAV) sprayers seem promising due to their potential to perform precision or spot spraying, particularly in woody crop environments where total surface spraying is unnecessary. However, incorporating this technology is limited by the lack of scientific knowledge about the environmental risks associated with UAV sprayers and the strict legal framework. Nonetheless, these spraying systems' characteristic downwash airflow and the limited swath width can potentially mitigate drift in hedgerow crops. During our study we performed comparative studies aimed to compare the airborne drift, soil, and crop depositions between a conventional orchard sprayer and a UAV sprayer in a commercial superhigh-density orchard in the South Iberian Peninsula in 2022. Our findings reveal that, in superhigh-density olive orchards, the UAV sprayer presents a substantial reduction in airborne drift, while soil depositions showed no significant differences compared to those of a conventional terrestrial orchard sprayer. Crop depositions were significantly lower when utilizing the UAV sprayer. These results suggest that introducing UAV spraying technology in Mediterranean agricultural systems, under specific scenarios, can effectively reduce the environmental impact of crop spraying and encourage the responsible use of plant protection products (PPPs).

Water use of a super high-density olive orchard submitted to regulated deficit irrigation in Mediterranean environment over three contrasted years

Water use of a super high-density olive orchard submitted to regulated deficit irrigation in Mediterranean environment over three contrasted years

Different Weed Managements Influence the Seasonal Floristic Composition in a Super High-Density Olive Orchard.

Weed management is not yet environmentally, agronomically, economically and socially sustainable in olive orchards. It is necessary to study appropriate integrated weed management systems (IWMSs) based on the knowledge of weed population and effects of weeding practices over time. The aim of this study was to evaluate the effects of different weed managements on seasonal floristic composition of a super high-density olive orchard, also exploiting the essential principles of an IWMS. Five weeding techniques were compared: chemical control (CHI), mowing (MEC), plastic (nonwoven tissue, TNT and polyethylene, PEN) and organic (with de-oiled olive pomace, DOP) mulching. Weed monitoring was carried out on six dates in a three-year period. The infestation of each of the main 18 weed species recorded (%) and the total infestation (%) on each monitoring date were determined. Results underlined that all weeding practices investigated in this multi-year study affected the floristic composition, weed characteristics (hemicryptophytes, cryptophytes and therophytes) and seed bank. TNT and PEN were the most effective methods for weed management. Particularly, total infestation coefficient was significantly lowest when plots were managed with TNT (13.91%) and PEN (14.38%) and highest for MEC (141.29%). However, DOP also significantly reduced infestation compared to CHI and MEC. Therefore, DOP could constitute an excellent strategy for weed management in super high-density olive groves, since it also has the possibility of distributing mulching materials in a mechanized way in field and can result in improvement of soil fertility and the possibility of valorizing waste. Further studies should be carried out to investigate the mechanism of action (physical and allelochemical) of de-oiled pomace or other organic agro-industrial materials and the recovery time of these mulching materials in super high-density olive orchards.

Drift reduction in orchards through the use of an autonomous UAV system

The demands of a growing population and a developing global economy will require an increase in agricultural yield of 70% over the next 30 years. However, achieving this goal is only possible with a sustainable intensification of agricultural systems. Spraying drones are one of the available technologies that could help meet this goal. Presently, the use of spraying drones is limited by both the legal framework and the lack of scientific knowledge about the drift they generate compared to conventional terrestrial spraying platforms. However, the flexibility that spraying drones provide, their characteristic vertical spraying, and the downwash airflow produced by the rotors might reduce drift. This study aimed to compare the drift generated by a conventional orchard sprayer to that generated by a spraying drone in a commercial superhigh-density olive orchard. Trials to assess the sedimented drift of both spraying platforms were conducted in the South Iberian Peninsula in 2022. Our results show that the drone sprayer required less than half the distance to sediment 90% of the sprayed volume compared to a conventional mist blower.

Effects of regulated, precision and continuous deficit irrigation on the growth and productivity of a young super high-density olive orchard

Water is the main limiting factor for olive cultivation in rainfed conditions. In irrigated orchards, water availability is scarce mainly during drought periods. Thus, increasing irrigation efficiency is a key issue to improve water management, especially in semiarid conditions. The objective of this study was to assess different irrigation strategies on tree growth and production components during three years in a young super high-density olive orchard (Arbequina cv.) located in northeast Spain. Four deficit irrigation strategies were compared to a control strategy based on replenishing crop evapotranspiration. The four strategies were as follows: Continuous Deficit Irrigation (CDI), two Regulated Deficit Irrigation strategies (Moderate, MRDI, and Severe, SRDI), and a precision Irrigation strategy based on daily trunk growth (Precision). In the Precision strategy, olive oil production increased by 7% and the vegetative variables did not show significant reductions, resulting in an average yearly water savings of 31% compared to the control strategy. The Regulated Deficit Irrigation strategies also produced promising results based on the high average yearly water-saving rates of 19% and 29%. However, the SRDI strategy exhibited significant reductions in tree height, lateral branches growth, olive yield, and oil yield compared to the control. On the other hand, the MRDI strategy did not differ significantly in oil yield, tree height, and lateral branches growth compared to the control or Precision strategies. Similarly, the CDI strategy resulted in significantly lower tree height, lateral branches growth, and production compared to the control. Although the observed reduced growth in both SRDI and CDI strategies presents an interesting opportunity for managing excessive vigor in super high-density olive orchards, it is important to consider that this approach may compromise production in successive seasons.

Influence of Regulated Deficit Irrigation on Arbequina’s Crop Yield and EVOOs Quality and Sensory Profile

Regulated deficit irrigation in super-high-density (SHD) olive orchards is a well-known strategy to save water and control plant vigor, without decreasing fruit or oil yield. As there is controversial information about its influence on virgin olive oil quality, a trial was conducted in five SHD olive orchards of Arbequina cultivar in different locations of central, east, north and northeast Spain under full irrigation (FI) and regulated deficit irrigation (RDI) treatments. RDI applied during phase II of fruit growing (40% of total needs) saves more than 20% of water on average, without reductions in olive fruit or extra virgin olive oil (EVOO) yield. No threshold of 3.5 MPa of stem water potential was crossed in any case. RDI modified sterols and the fatty acid profile of EVOOs but not phenols, quality parameters, or the sensory profile. Latitude, altitude, and yearly rainfall have a big impact on some compounds such as campesterol, oleuropein, or margaroleic or linolenic acids.

Exploring the use of synthetic aperture radar data for irrigation management in super high-density olive orchards

Understanding the plant water-uptake dynamics and behavior in olive orchards is an area of much interest, particularly for efforts to optimize the use and application of water resources. However, plant water-uptake information is rarely available or consistently monitored for large agricultural areas, especially in developing countries. Here we evaluate the potential of using synthetic aperture radar (SAR) images to monitor the water-uptake rate in super high-density olive orchards located in the hot and arid desert climate of Saudi Arabia. The experiment was performed using Sentinel-1 data acquired between 2019 and 2020 in concert with in situ sap flow measurements. To date, no study has explored the potential of Sentinel-1 SAR data to assess the water-uptake rate in olive orchards. The results demonstrate that the SAR backscatter increased between January and July/August, and then decreased during the remainder of the year, following a broadly Gaussian distribution. Of key interest is the strength of the relationship between the increasing and decreasing trends of SAR backscatter and the variation in the coincident water-uptake rate measured in situ, producing a coefficient of determination of 0.81 in the VV polarization. As the relationship between the SAR backscatter and water-uptake rate was established for plots with similar tree type and planting density, further exploration of orchards with different characteristics and planting densities is needed to fully understand the potential of SAR data to estimate plant water-uptake. Overall, the study demonstrates that SAR data can track variation in locally measured water-uptake and illustrates the potential to assist with enhancing irrigation management.

Impact of Super-High Density Olive Orchard Management System on Soil Free-Living and Plant-Parasitic Nematodes in Central and South Italy.

Simple SummarySuper-high density olive orchards are spreading in Italy to reduce production costs and increase yields per hectare. The objective of this study was to assess the orchards’ effect on the soil nematode community in five sites located in the main Italian olive cultivation areas compared to the adjacent traditional olive orchard system. Super-high density olive orchard management combined with conventional tillage and mineral fertilization decreased total organic carbon compared to traditional management. The soil nematode community was affected by the depletion of organic matter, especially for plant-parasitic nematodes, which increased. Moreover, this investigation evidenced that the Super-high density olive orchard management system could change the soil plant-parasitic nematode composition of olive orchards. In fact, the families Telotylenchidae, Paratylenchidae, Meloidogynidae, and Criconematidae were favored in the Super-high density olive orchard system, while Longidoridae, Heteroderidae, and Pratylenchidae were disadvantaged. However, conservative and sustainable soil management might maintain or improve the soil nematode community functionality and reduce plant-parasitic nematodes.The soil nematode community plays an important role in ecosystem services. The objective of this study was to assess the effect of Super-high density (SHD) olive orchards on the nematode community in five sites with different soils, climates, and cultivars. At each site, the SHD management system was compared to the adjacent olive orchard traditional (TRAD) system, in which the same soil management and phytosanitary measures were applied. Soil management was assessed by total organic carbon content (TOC), while the soil nematode community was evaluated using the nematode taxa abundances and soil nematode indicators. TOC was significantly decreased in the SHD olive orchard system compared to TRAD in the sites characterized by conventional tillage and mineral fertilization. The two-way ANOSIM analysis on nematode abundance showed no difference between the two olive management methods, instead showing only a significant difference per site mainly due to variabilities in plant-parasitic nematode assemblage. However, a negative impact of SHD management was evident in environments stressed by summer droughts and conventional tillage: the ratio of obligate plant-parasites to bacterivores and fungivores (Pp/(B+F)) was significantly higher in SHD than in the TRAD olive orchard system, and the prey-to-predator θ mass ratio showed the lowest values in the sites under organic fertilization or green manure. The canonical correspondence analysis showed that the free-living nematodes were only slightly affected by SHD olive orchards; instead, the presence of plant-parasitic nematodes families such as Telotylenchidae, Paratylenchidae, Meloidogynidae, and Criconematidae was favored, in comparison to Longidoridae, Heteroderidae, and Pratylenchidae.

How Could Precision Irrigation Based on Daily Trunk Growth Improve Super High-Density Olive Orchard Irrigation Efficiency?

Water deficit, especially during summer, is currently one of the most important stress factors that influence olive oil production in olive orchards. A precision irrigation strategy, based on daily trunk growth, was assessed and compared with one continuous deficit, one full irrigation, and two different regulated deficit irrigation strategies. All of them were tested in a super high-density olive orchard located in northeast Spain, in which oil production, main oil production components, applied irrigation water, and water productivity were assessed. For this purpose, the crop was monitored from budding to harvesting, mainly during the summer months in which the Precision strategy only applied water after two days of negative daily trunk growth. Maximum monthly water savings for the Precision strategy reached 91.8%, compared with full irrigation, while major annual mean water savings reached 50% for the continuous deficit strategy and 31.2% for the Precision strategy, which also reduced irrigation events by up to 19.7%, compared with the full irrigation strategy. Oil production and oil production components varied depending on the irrigation strategies providing the Control, one of the regulated deficit irrigations, and Precision higher values than the other strategies; oil yield results differ, nonetheless. The Precision strategy showed an overall better performance. Despite this, it did not achieve the highest water saving, it achieved higher water productivity.

Water productivity and economic analyses for super high density olive orchards

Water productivity and economic analyses for super high density olive orchards

Effect of progressive irrigation water reductions on super-high-density olive orchards according to different scarcity scenarios

The cultivation of super-high-density (SHD) olive orchards in the Mediterranean Basin usually faces drought events due especially to low precipitation, high temperature and solar radiation in summer. Hence regulated deficit irrigation (RDI) strategies can be a useful tool for irrigation management to limit yield loss. Therefore, this work aimed to find the most suitable RDI strategy by placing special emphasis on phase II of fruit growth for SHD olive orchards irrigated below theoretical water requirements. Four irrigation strategies were defined according to different water availability scenarios: fully-irrigated, RDI1, RDI2 and RDI3, scaled to respectively supply 450, 350, 250 and 150 mm year-1. Tree water relations, trunk growth, fruit and oil yields, were evaluated. The study was carried out for 5 years in an ‘Arbequina’ commercial orchard (1667 trees ha-1) in Villena, Alicante (Spain). The main results showed that ‘Arbequina’ tree irrigation water productivity (both olive and oil) gradually increased as irrigation dose lowered. Olive yield depended heavily on the applied irrigation dose, with the highest olive yield for the Control trees. However, the oil yield in the RDI1 trees was similar to that of the Control trees, but strategies RDI2 and RDI3 reduced yield. All the RDI strategies diminished vegetative development, and RDI2 was the most efficient strategy for resource distribution (olive yield vs. vegetative growth). Therefore based on oil production, vegetative growth and irrigation water savings, RDI1 was the most recommendable irrigation strategy for the Arbequina’ olive trees cultivated in SHD under semi-arid Mediterranean conditions.

Response of vegetative and fruit growth to the soil volume wetted by irrigation in a super-high-density olive orchard

In most fruit tree orchards under localised irrigation, only a fraction of the rhizosphere is wetted by irrigation. As this may reduce growth and production, such that there is a demand for information on the optimum number and location of emitters. In a mature ‘Arbequina’ olive orchard with 1667 trees ha-1, we analysed the impact of applying the same amount of water with one vs. two drip irrigation pipes (laterals) per tree row. We had trees under full irrigation, for which irrigation supplies amounted to 80–100% of the crop water needs (ETc), and two deficit irrigation treatments supplying ca. 40% of ETc. We used the HYDRUS 2D/3D (v. 1.11) model to simulate the shape and volume of the fraction of the rhizosphere wetted by irrigation (irrigation bulbs), as well as drainage and soil evaporation. For both full irrigation and deficit irrigation, differences in the soil volume and the soil surface wetted by irrigation were not sufficient to affect drainage and soil evaporation. The greatest values of root length density and root surface per unit volume were found in trees under deficit irrigation with two laterals, and the lowest in fully irrigated trees with one lateral. This, however, was counterbalanced by both the greater size of the irrigation bulbs and the greater soil water contents in the bulbs of the fully irrigated trees, such that water uptake was not enhanced by the second lateral. For 2 consecutive years we found no impact of irrigating with one or two laterals per tree row on water potential and stomatal conductance, shoot and fruit growth, leaf area and production, either for full irrigation or deficit irrigation conditions. Therefore, our findings suggest no benefits of irrigating super high density olive orchards with two laterals instead of one.

Opportunities of super high-density olive orchard to improve soil quality: Management guidelines for application of pruning residues

Applying pruning residues in the lanes of olive groves has become a popular practice because it is economical and accrues benefits for soil and water management. This study presents an analysis of the impact of different rates of pruning residue on soil properties, in particular related with soil quality. Over 4 annual campaigns, chopped pruning residues used as a mulch were analyzed in terms of composition, coverage and moisture content to evaluate their effects on the amount of soil organic carbon (−10 cm and −20 cm) and CO2 emissions, temperature and moisture. The experiment was carried out in a super-intensive olive orchard in Cordoba (SE, Spain) and used four amounts of fresh pruning residue: 7.5 t ha⁻1(T1), 15.0 t ha⁻1 (T2) and 30.0 t ha⁻1 (T3), with a control T0 = 0.0 t ha1.Mulch mean leaf fraction was 46.0 ± 17.5% (±SD) and initial water content, 24.8 ± 8.6%. The mulching benefits for soil moisture were observed in amounts of pruning residue >7.5 t ha⁻1, which are only produced in super-intensive olive groves or in orchards with high tree densities. The low impact of the treatments on soil moisture was explained by the dramatic annual variations in residue moisture contents, caused by the regimes of high temperatures and rainfall-evapotranspiration deficits inherent to the Mediterranean Basin climate. Thus, the mulching capacity only resulted efficient when the residues were still humid in spring. In addition, 15.0 t ha⁻1 of pruning residues was the threshold to provide significant increases in soil organic carbon at depths of 0–20 cm. Thus, accumulating pruning residue in lanes at rates of over 15 t ha⁻1 (T2 and T3) is more convenient than a uniform distribution with lower amounts, due to the low mineralization rates occurring during warm seasons and the larger inputs of OM increasing the annual balance of SOC.

Intercepted Photosynthetically Active Radiation (PAR) and Spatial and Temporal Distribution of Transmitted PAR under High-Density and Super High-Density Olive Orchards

We quantified the photosynthetically active radiation (PAR) interception in a high-density (HD) and a super high-density (SHD) or hedgerow olive system, by measuring the PAR transmitted under the canopy along transects at increasing distance from the tree rows. Transmitted PAR was measured every minute, then cumulated over the day and the season. The frequencies of the different PAR levels occurring during the day were calculated. SHD intercepted significantly but slightly less overall PAR than HD (0.57 ± 0.002 vs. 0.62 ± 0.03 of the PAR incident above the canopy) but had a much greater spatial variability of transmitted PAR (0.21 under the tree row, up to 0.59 in the alley center), compared to HD (range: 0.34–0.43). This corresponded to greater variability in the frequencies of daily PAR values, with the more shaded positions receiving greater frequencies of low PAR values. The much lower PAR level under the tree row in SHD, compared to any position in HD, implies greater self-shading in lower-canopy layers, despite similar overall interception. Therefore, knowing overall PAR interception does not allow an understanding of differences in PAR distribution on the ground and within the canopy and their possible effects on canopy radiation use efficiency (RUE) and performance, between different architectural systems.

Water use indicators and economic analysis for on-farm irrigation decision: A case study of a super high density olive tree orchard

Increasing the efficiency of on-farm water use requires wise decisions on the irrigation system, the irrigation strategy and the method to schedule irrigation, among other factors related to water management. Since the early 2000s, the water productivity approach has been widely used to address this issue. It provides useful indicators to both the biophysical water productivity and the economic performance of irrigation. Analysis of the literature, however, shows both confusion on the use of terms and lack of agreement on the equations. We have addressed the rational use of the water productivity approach for the irrigator to improve both biophysical and economic water productivity at the field scale. We also addressed the increasing use of the water footprint approach at the field scale. The literature shows a lack of consensus on the reliability of the conceptual framework behind that approach. We focused on its potential for irrigation decision making, and concluded that it is not advantageous, as compared to the water productivity approach, for assessing on-farm water use. In addition, we show a case study of a super high density olive orchard which analyses the joint use of economic water productivity indicators and both production and profit functions to improve decision making.

Crop Coefficients and Transpiration of a Super Intensive Arbequina Olive Orchard using the Dual Kc Approach and the Kcb Computation with the Fraction of Ground Cover and Height

The SIMDualKc model was used to simulate crop water requirements for a super high density olive orchard in the region of Alentejo, Portugal. This model uses the dual crop coefficient approach to estimate and partitioning the actual crop evapotranspiration (ETc act) and therefore to perform the soil water balance. The model was calibrated with 2011 tree transpiration using trunk sap flow measurements and was validated using similar data from 2012 and tested with 2013 data. Low root mean square errors (RMSE < 0.53 mm·d−1) and acceptable modelling efficiency indicators (EF > 0.25) were obtained. Further validation was performed comparing modelled ETc act with eddy covariance measurements. These indicators support the appropriateness of using SIMDualKc to guide irrigation management. The basal crop coefficient (Kcb) curves obtained with SIMDualKc for those 3 years were compared with the Kcb values computed with the Allen and Pereira approach (A&P approach) where Kcb is estimated from the fraction of ground cover and plant height considering an adjustment factor for crop stomatal control (Fr). Fr values were obtained through a trial and error procedure through comparing the Kcb estimated with this approach and with SIMDualKc. The Kcb curves obtained by both methods resulted highly correlated, which indicates that the A&P approach may be used in the irrigation management practice to estimate crop water requirements. Results of performing the soil water balance with SIMDualKc have shown that soil evaporation is a large fraction of ETc act, varying between 41% and 45% for the 3 years under study. Irrigation, applied with a drip system, represented 39 to 56% of ETc act, which shows the great importance of irrigation to achieve the water requirements of super intensive olive orchards. Nevertheless, the analysis has shown that the irrigation management adopted at the orchard produces a water deficit larger than desirable, with a ratio of ETc act to non-stressed crop evapotranspiration (ETc) varying from 70% to 94% during the mid-season, when that ratio for a eustress irrigation management could be around 90%.

Water status, gas exchange and crop performance in a super high density olive orchard under deficit irrigation scheduled from leaf turgor measurements

We evaluated the suitability of scheduling a regulated deficit irrigation strategy in a hedgerow olive orchard with high plant density from leaf turgor related measurements. Measurements were made for two consecutive years at an olive orchard with 1667 ‘Arbequina’ trees per hectare where we had two deficit irrigation treatments, 45RDICC and 45RDITP, plus a full irrigation as a control. The two 45RDI treatments consisted on applying the same regulated deficit irrigation strategy, aimed to supply a total of 45% of the irrigation needs. The 45RDICC treatment however, was scheduled with the crop coefficient approach, while the 45RDITP treatment was scheduled with an irrigation scheduling approach based on leaf turgor related measurements, first suggested by Padilla-Díaz et al. (2016, Agric. Water Manage. 164:28–37). They worked at the orchard in 2014, and made a preliminary evaluation of the irrigation scheduling approach by comparing 45RDITP versus 45RDICC in terms of irrigation dose and frequency, predawn and midday stem water potential (Ψstem), and the fruit yields of each treatment. In this work, we considered the same variables as well as maximum daily values of stomatal conductance and CO2 net assimilation, the seasonal courses of the number of internodes in current-year shoots, leaf area and oil accumulation in the fruits, and total fruit and oil yields. All those variables were monitored both in 2014 and 2015, and we found no differences between the 45RDITP and the 45RDICC treatments, for any of them. The irrigation amounts applied to each treatment differed occasionally, but the total water supplies were similar to both 45RDI treatments. Our results, therefore, confirm the suitability of the irrigation scheduling approach proposed by Padilla-Díaz et al. (2016) to apply regulated deficit irrigation in commercial hedgerow olive orchards. We found additional evidence for the 15% changes on the irrigation amount recommended by the irrigation scheduling approach as being suitable for the orchard conditions. Caution must be taken when applying this approach to other olive orchards, since the relations between the tree water status and the shape of the daily curves recorded with the ZIM probes may depend on the cultivar and orchard conditions.

Olive oil quality response to irrigation cut-off strategies in a super-high density orchard

An increase in olive oil consumption has occurred worldwide in the last decades and has resulted in more land area being dedicated to olive orchards in several southern hemisphere countries. In order to achieve sustainable productivity under the increasing water scarcity, optimal water use is essential. Thus, a field experiment was conducted during four consecutive growing seasons (2010–2011 to 2013–2014) to evaluate olive oil quality in response to irrigation cut-off strategies applied after fruit set using midday stem water potential (Ψstem) thresholds in a super-high density olive orchard (cv. Arbequina) located in the Pencahue Valley, Maule Region, Chile. The experimental design was completely randomized with four treatments and four replicates. In treatment T1 (control), Ψstem was between −1.4 and −2.2 MPa (100% of actual evapotranspiration) throughout the season, while the T2, T3 and T4 treatments did not receive irrigation from fruit set until they reached a Ψstem threshold of approximately −3.5, −5.0, and −6.0 MPa, respectively. Once these thresholds were reached, irrigation was reestablished and maintained as T1 in all treatments until olives were harvested. Fruit oil and water content (%) at harvest were not affected by the different treatments. Free acidity was also not affected, while peroxide and extinction coefficients only showed minor differences between treatments that were within the limits established for commercial extra virgin oil quality. Total polyphenols at harvest were much higher in the water deficit treatments and showed a significant linear relationship each year with the water stress integral. The percentages of the main fatty acids were not affected by the treatments. However, they were significantly different between seasons. Sensory tests indicated that the higher total polyphenol content positively contributed to more pronounced bitter and pungent attributes of olive oil from trees with higher water deficit. Thus, the irrigation cut-off strategies evaluated at our four-year study can be an excellent management tool to both improve the oil quality of cv. Arbequina and reduce water use in super-high density orchard.