A Comparative Study of the Growth, Yield, and Physiological Responses of Arbosana, Arbequina, Coratina, and Maraqi Olive Cultivars

A Comparative Study of the Growth, Yield, and Physiological Responses of Arbosana, Arbequina, Coratina, and Maraqi Olive Cultivars | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article A Comparative Study of the Growth, Yield, and Physiological Responses of Arbosana, Arbequina, Coratina, and Maraqi Olive Cultivars Abd El-wahed N. Abd El-wahed, Ibrahim A. Elnaggar, Hosny F. Abdel-Aziz, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8662502/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 17 You are reading this latest preprint version Abstract Expanding olive cultivation into marginal, newly reclaimed soils is vital for meeting global demand but poses significant challenges due to abiotic stresses. Success in these conditions depends heavily on cultivar selection, but there is a dearth of comparative information on contemporary cultivars in these settings. To evaluate the performance of four olive cultivars Arbosana, Arbequina, Coratina, and Maraqi in a recently reclaimed sandy soil, this study carried out an extensive two-year field experiment. A range of physiological (chlorophyll content, relative water content (RWC), leaf proline concentration, reproductive (inflorescence traits, fruit set, yield), vegetative growth, and fruit physical properties, oil content parameters were evaluated. The findings showed that adaptive strategies varied significantly by genotype. With the highest absolute fruit yield, the most vigorous vegetative growth, and the highest oil content, "Coratina" demonstrated a high-productivity but high-stress strategy. However, this was accompanied by the highest proline accumulation and the lowest RWC, suggesting extreme physiological stress. However, "Arbequina" and "Arbosana" showed a cautious, effective approach, maintaining a high RWC with little proline accumulation and achieving superior yield efficiency (kg fruit/m³ canopy), which is a sign of successful stress avoidance. With intermediate growth and yield, the highest RWC, and the lowest proline levels, "Maraqi" showed a balanced, stress-avoidant profile that suggested strong innate resilience. The results show a basic trade-off between resource use efficiency and productivity. In conclusion the best cultivar selection depends on management objectives and resource availability: "Coratina" for maximizing yield in situations where resources are not limited, "Arbequina" and "Arbosana" for high density, resource efficient intensive systems, and "Maraqi" as a robust option for sustainable cultivation in unpredictable water regimes. Biological sciences/Ecology Earth and environmental sciences/Ecology Biological sciences/Physiology Biological sciences/Plant sciences Olea europaea L. cultivar selection proline water relations yield efficiency Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 1. Introduction The olive ( Olea europaea L.) has a global reach and reflects a growing trend of olive cultivation into arid and semi-arid areas due to demand for its oil and climate resilient agriculture[ 1 ]. In this new context, often associated with salinity, low organic matter, low fertility, and poor water retention, new reclaimed soils represent a frontier for agricultural development, but it is also a significant agronomic opportunity[ 2 ]. The olive tree is recognized for its drought tolerant and tolerant of marginal conditions, therefore it is well suited to these new lands[ 3 ]. However, its widely touted resilience is a general species characteristic that belies substantial genotypic variation. Thus, choice of cultivar is the most important aspect of whether olive orchards will establish and produce successfully in these high-stress environments[ 4 ]. The genotypic response to abiotic stress is a complex function of physiological, morphological and biochemical acclimatization. Recommended cultivars for marginal lands not only need to survive but also need to demonstrate productivity sustainability and fruit quality. This entails evaluating cultivars holistically beyond yield components when assessing physiological measures of stress response. Chlorophyll content determined by SPAD readings reflects photosynthetic ability and nitrogen status, which is often impaired under stress[ 5 ]. Relative Water Content (RWC) is the first measure of a plant's water balance and a drought avoidance measure[ 6 ]. Accumulation of osmolytes, specifically proline, has been well-described as a biochemical response to osmotic stress, and acts as a marker for the degree of abiotic pressure and the plant's response to lessen the effects of the stress[ 7 ]. At the same time, agronomic performance determined by vegetative growth (canopy volume, shoot growth), reproductive performance (fruit set, yield efficiency) and final fruit quality (oil content) determine the sustainability of a given cultivar [ 8 ]. This study aims to compare the performance of four distinct cultivars that appear potential candidates for intensive plantings: Arbosana, Arbequina, Coratina, and Maraqi. Arbequina and Arbosana are Spanish cultivars that are the basis for most high density and super high-density planting systems throughout the world and are desirable due to their lower vigor and high early productivity[ 9 ]. Coratina, an Italian cultivar, is aesthetically appealing for its high polyphenolic nutrient content but has higher vigor and may have different physiological resource requirements and tolerances for stress[ 10 ]. Finally, Maraqi, which is primarily cultivated in North Africa and the Middle East, is expected to have inherent adaptive properties for heat and drought stress[ 11 ] but is not well represented in international scientific literature. It should be noted that the cultivar performance rank is not permanent, but it is related to whatever the genotype-by-environment (G×E) interaction entails. A cultivar that thrives within the traditional Mediterranean basins may have poor performance potential in the edapho-climatic conditions imposed through the reclamation of new soils, where least constraints like salinity and lower water holding capacity are used to classify the soils. There is a marked shortage of rigorous, multi-factorial comparative studies that compare these cultivars directly under the same stress levels associated with newly reclaimed land. Most existing studies are in established growing areas or only monitor a limited number of parameters. A study that combines physiological stress biomarkers, along with agronomic and pomological information, will be important for making sound, evidence-based recommendations to growers. This study was, therefore, developed to provide the ultimate comparison of the adaptive and productive performance of Arbosana, Arbequina, Coratina and Maraqi cultivars of olives grown in new reclaimed soils. We hypothesized that the four cultivars would exhibit distinct adaptive syndromes, resulting in significant trade-offs between vegetative vigor, physiological stress tolerance, and reproductive efficiency under the conditions of newly reclaimed soil. 2. Materials and Methods 2.1. Site Description and Experimental Orchard Establishment The study was conducted over two consecutive growing seasons (2024 and 2025) at a private orchard located at Wadi Al-Natrun region (Coordinates: approximately 30°24'01.7"N 30°02'20.6" E), El- Behera Governorate, Egypt, planted in sandy soil at 4 × 6 m apart. The region is characterized by an arid and semi-arid climate according to the Köppen-Geiger climate classification[ 12 ]. Meteorological data recorded by an onsite weather station showed average maximum temperatures of 35.8°C in summer and 19.5°C in winter, with an average annual rainfall of < 50 mm, necessitating a full irrigation regime. The orchard was established in early 2015. Ten-year-old, own-rooted cuttings, uniform trees of the four olive cultivars (Arbosana’, ‘Arbequina’, ‘Coratina’, and ‘Maraqi’) were sourced from a certified commercial nursery. The experimental design was a Randomized Complete Block Design (RCBD) with four blocks (replications), each containing four rows of trees (one row per cultivar). Each experimental unit (plot) consisted of 5 trees, with the three central trees used for data collection to avoid edge effects, totaling 16 plots and 80 trees. 2.2. Agronomic Management A common agronomic management practice was applied to all cultivars. Drip irrigation was employed using two pressure-compensating drippers (4 L h⁻¹) per tree. Fertilization followed soil analysis recommendations and standard practices for young olive orchards[ 13 ]. Annually, 1000 g N, 500 g P 2 O 5 and 900 g K 2 O per tree were applied through the fertigation system. 2.3. Data Collection and Measurements Data were collected on the three central trees of each plot during the two study seasons. Moreover, the plant materials were collected from a private orchard with the full permission of the landowner. 2.3.1. Vegetative Growth Parameters: Canopy Volume (m³) : Estimated using the formula for a prolate spheroid: V = (4/3) × π × (H/2) × (W/2)², where H is the canopy height and W is the mean canopy diameter [ 14 ]. Shoot Length (cm) Twenty well-developed, one-year-old shoots per tree were tagged, and their elongation was measured at the end of the growing season. Leaf Area (cm²) The area of 50 mature, fully expanded leaves per tree was measured using a portable leaf area meter (LI-3000C, LI-COR Biosciences). 2.3.2. Physiological Parameters: Leaf Chlorophyll Content : Estimated using a portable SPAD-502Plus chlorophyll meter (Konica Minolta). Readings were taken on clear days between 10:00 and 12:00 on 30 sun-exposed, mature leaves per tree[ 15 ]. Relative Water Content (RWC%) : Measured according to the method of Slama et al.[ 16 ]. Ten leaf discs per tree were sampled, fresh weight (FW) recorded, turgid weight (TW) obtained after floating on distilled water for 24h in the dark, and dry weight (DW) measured after oven-drying at 70°C to constant weight. RWC was calculated as: RWC (%) = [(FW - DW) / (TW - DW)] × 100. Leaf Proline Content (µmol g⁻¹ FW) Quantified using the acid-ninhydrin method described by Bates et al. [ 17 ]. Proline was extracted from 0.5 g of fresh leaf tissue and its concentration determined spectrophotometrically at 520 nm using L-proline as a standard. 2.3.3. Flowering characteristic Genetic Sterilities The fruit set in olive trees is mainly determined by the following two traits: pistil abortion (female sterility) and self-incompatibility[ 18 ]. In our study, we evaluated these two forms of genetic sterility using four cultivars: 'Arbosana', 'Arbequina', 'Coratina', and 'Maraqi' grown for two consecutive seasons (2024–2025). To determine gynosterility, we sampled 60 inflorescences per tree at the time of blooming from three separate canopy heights (0.5–1.0 m, 1.0–1.5 m, and 1.5–2.0 m). To assess self-incompatibility, we followed the procedures established in [ 19 ]. We used 50 inflorescences from each tree, divided between both east and west sides of the canopy. The inflorescences in one group were covered with non-woven bags prior to anthesis thus that they could only self-pollinate by wind-assisted movement. The other group's inflorescences were left exposed for wind-assisted cross-pollination. After veraison, fruit set was assessed for both groups. In addition to assessing the above two forms of genetic sterility, we also monitored the blooming period of the inflorescences in the open-pollination group on a weekly basis. We defined the different phenological stages based on the percentages of inflorescences open as follows: 10% (beginning), 50% (full bloom), and 90% (end of bloom). 2.3.4. Yield and Fruit Characteristics: Fruit Yield (kg tree⁻¹) The total fruit weight from each tree was recorded at commercial harvest maturity (determined by a fruit maturity index). Yield Efficiency (kg m⁻³) Calculated as the ratio of fruit yield to canopy volume[ 20 ]. Fruit physical properties A random sample of 50 fruits per tree was used to measure fruit weight, length, and width using a digital caliper. The pulp-to-pit ratio was determined by manually separating and weighing the components. Oil Content (% on dry weight) : To determine the total amount of extracted oil from the harvested fruit, an average sample weighing 100 g was obtained from each replicate. Each sample was extracted using a Soxhlet extractor with petroleum ether (boiling between 40 and 60°). The length of time for each extraction was 6 hours. Any petroleum ether remaining in the oil/solvent mixture was removed using a rotary evaporator (Heidolph, Germany) set at 40°. The remaining oil was brought to a temperature of 105° using an oven and dried for 1 hour to eliminate water and/or residual petroleum ether prior to recording the final weight of the oil collected from the extracted fruit[ 21 ]. Finally, an oil yield (kg/tree) was calculated for each tree based on the percentage of oil collected from the extracted sample divided by the tree's total harvest weight. Statistical Analysis All data were subjected to one-way Analysis of Variance (ANOVA) using the general linear model (GLM) procedure in co-stat software (version. 6.0). Mean separation was performed using Duncan’s Multiple Range Test (DMRT) at a significant level of p ≤ 0.05. All assumptions of ANOVA, including normality and homogeneity of variances were tested and met. 3. Results 3.1. Vegetative Growth Performance The analysis of vegetative growth parameters revealed significant differences among the four olive cultivars in their adaptation to the conditions of the newly reclaimed soil over the two study seasons. The genotype by environment interaction was also significant, indicating that the cultivars responded differently to the inter annual variations in climatic conditions. Canopy volume, a primary indicator of tree vigor and establishment, data in (Fig. 1 A) showed a clear and consistent hierarchy among the cultivars. 'Coratina' demonstrated the most robust growth, achieving a significantly larger canopy volume than all other cultivars. Conversely, 'Arbequina' and one of the 'Arbosana' trees exhibited the most constrained growth, consistently registering the smallest canopy volumes and belonging to the lowest statistical grouping (Group D). The 'Maraqi' cultivar displayed intermediate vigor, its canopy volume not being statistically different from the larger 'Arbosana' plot in one season and forming an intermediate group (B/C) in the other. This indicates a moderate adaptive capacity in terms of vegetative development. Data in (Fig. 1 B and C) clearly showed that shoot length and leaf area data corroborated the findings on canopy volume, reinforcing the vigor ranking of the cultivars. 'Coratina' again consistently produced the longest shoots and the largest leaves, significantly outperforming the other cultivars. This enhanced photosynthetic machinery (larger leaf area) likely contributes to its greater biomass production (canopy volume). Physiological Responses to Abiotic Stress The physiological parameters measured provide a critical lens into the underlying strategies employed by each cultivar to cope with the abiotic stresses likely including salinity, heat, and water deficit inherent to the newly reclaimed soil. The significant differences observed highlight distinct adaptive mechanisms. 2.1. Leaf Chlorophyll Content Results in (Fig. 2 A) showed that leaf chlorophyll content (SPAD) concentrations, an indicator of photosynthetic potential and nitrogen status, revealed a clear genotypic gradient. 'Coratina' consistently maintained the highest chlorophyll concentration, significantly exceeding the other cultivars. This attribute can be advantageous for productivity but may also increase the risk of photo-oxidative damage under extreme light and temperature stress. Conversely, 'Maraqi' registered the lowest SPAD values in both seasons. 'Arbequina' and 'Arbosana' exhibited intermediate chlorophyll levels, positioning them between the two extremes. 2.2. Plant Water Status Relative water content (RWC%) is a primary indicator of a plant's hydration and its ability to maintain water balance. The data in (Fig. 2 B) uncovered a striking contrast in water relations strategies among the cultivars. 'Maraqi' and 'Arbequina' demonstrated the strongest ability to maintain tissue hydration, consistently achieving the highest RWC values and forming the top statistical group. This trait is a key marker of drought avoidance. In stark contrast, 'Coratina' exhibited the lowest RWC values, significantly lower than all other cultivars. This suggests a different strategy, often termed drought tolerance. 'Coratina' appears to continue transpiring and growing even as soil water decreases, enduring lower tissue water potential. This strategy relies on a robust root system and cellular-level tolerance to dehydration but carries a higher risk of hydraulic failure under prolonged or severe drought. 'Arbosana' showed an intermediate RWC, indicating a moderate water conservation ability. 2.3. Proline content of leaf The results in (Fig. 2 C) showed that 'Coratina' accumulated proline to a significantly greater extent than all other cultivars in both seasons. This markedly high concentration signifies that 'Coratina' was experiencing the highest level of physiological stress among cultivars. Proline functions as a compatible osmolyte for osmotic adjustment, a stabilizer of proteins and membranes, and a ROS scavenger. The high investment in this pathway is consistent with its tolerance strategy but also highlights the significant metabolic cost associated with its growth under these conditions. Conversely, 'Maraqi' and 'Arbequina' maintained the lowest proline levels. This finding is critical, as it aligns that aligns perfectly with their high RWC. 3. Reproductive Development and Yield Formation The investigation of reproductive parameters revealed profound and statistically significant differences ( p < 0.05) among the cultivars, revealing distinct reproductive strategies and their efficacy in the challenging environment of newly reclaimed soil. 3.1. Flowering Capacity and Quality A clear hierarchy was observed in flowering traits. 'Coratina' consistently produced the longest inflorescences and the highest number of flowers per inflorescence, significantly outperforming the other three cultivars (Fig. 3 A and B). Conversely, 'Arbosana' and 'Arbequina' exhibited more conservative flowering, with significantly shorter rachises and fewer flowers per inflorescence. 'Maraqi' consistently displayed an intermediate flowering capacity, positioned between the two extremes. However, quantity was inversely related to quality. The other cultivars maintained significantly lower and statistically similar gynosterility rates, with 'Maraqi' showing a tendency toward higher abortion in the second season, suggesting a potential sensitivity to specific environmental conditions. 3.2. Fruit Set % The culmination of flowering and pollination success is reflected in the fruit set (%) data. Here, the strategy of the different cultivars becomes starkly evident. 'Arbequina' and 'Arbosana' achieved the highest fruit set percentages, successfully converting a large proportion of their fewer flowers into developing fruits (Fig. 3 C). This high efficiency is a hallmark of modern cultivars bred for intensive systems and indicates effective pollination and good carbohydrate availability during the critical fruit set period[ 22 ]. Despite its immense number of flowers, 'Coratina' registered the lowest fruit set percentage by a significant margin. This is a direct consequence of its high gynosterility and likely also due to intense internal competition for carbohydrates among its enormous number of fruitlets, leading to a high rate of abscission (Fig. 3 D). 'Maraqi' demonstrated a fruit set percentage that was intermediate but statistically lower than the efficient setters, indicating a moderate conversion efficiency. 3.3. Fruit yield (kg/tree) The interplay between vegetative growth (as represented by canopy volume from the previous analysis) and reproductive output defines the economic productivity of the orchard. 'Coratina' achieved the highest absolute Yield (kg/tree) (Fig. 4 A), a direct result of its massive vegetative structure and its strategy of compensating for low fruit set with an exceptionally high initial flower number. Its large canopy was able to support this considerable fruit load. In contrast, the lower-vigor cultivars 'Arbequina' and 'Arbosana' produced significantly less fruit on a per-tree basis, which is an expected outcome given their significantly smaller canopy size. However, when evaluating Yield Efficiency (kg fruit per m³ of canopy), this metric revealed a contrasting pattern. 'Arbequina' and 'Arbosana' demonstrated superior efficiency, producing significantly more fruit per unit of vegetative structure (Fig. 4 B). The high efficiency of these cultivars means they deliver a higher return on investments in water, nutrients, and land area dedicated to canopy growth. 'Coratina' and 'Maraqi' exhibited statistically similar but significantly lower yield efficiency. For 'Coratina', this confirms that a substantial portion of its resources is allocated to maintaining its large vegetative framework rather than being directed toward fruit production. The low efficiency of 'Maraqi' suggests that its balanced growth strategy, while stable, does not translate into high reproductive efficiency under these conditions. For orchardists in newly reclaimed areas, this trade-off is central to cultivar selection. Choosing 'Coratina' prioritizes ultimate per-tree production but requires more space and resources per unit of yield. Choosing 'Arbequina' or 'Arbosana' prioritizes maximizing output per land area, water volume, and input investment, which is typically the goal of modern olive cultivation. 4. Physical fruit characteristics 4.1. Fruit size and weight A consistent and significant hierarchy was observed for fruit weight and fruit volume across both seasons. 'Coratina' consistently produced the largest and heaviest fruits, and significantly outperforming the other cultivars (Fig. 5 A). The Italian origin of 'Coratina' has selected for larger fruit size compared to Spanish cultivars. 'Arbequina' consistently produced fruits that were significantly larger and heavier than those of 'Arbosana' and 'Maraqi'. This finding is crucial for orchard management, as fruit size can influence harvesting efficiency and processing parameters. The larger fruit volume of 'Arbequina' may also make it marginally more suitable for table olive production in addition to oil extraction (Fig. 5 B). The stability of this ranking across seasons underscores the strong genetic control over this trait. 4.3. Oil Content % The Oil Content (% dry weight) is the ultimate qualitative parameter for oil-dedicated cultivars. 'Coratina' demonstrated a clear superiority, achieving significantly higher oil content than all other cultivars in both seasons (Fig. 6 ). This high oil concentration, combined with its large fruit size and high absolute yield, makes 'Coratina' an outstanding cultivar for oil production in terms of quantitative output. 'Arbequina' and 'Maraqi' registered statistically similar oil contents, forming a middle group. While lower than 'Coratina', their oil content is still commercially viable and aligns with standard expectations for these cultivars. The data suggests that 'Arbosana' may have slightly higher oil potential than 'Arbequina' and 'Maraqi', particularly in the second season where it grouped with 'Coratina', though more data would be needed to confirm this trend. This potential for high oil yield in a compact tree is a key reason for 'Arbosana's' popularity in high-density systems. In conclusion, the comparative analysis of fruit morphology and oil content confirms that there is no single "best" cultivar. The optimal choice is a function of the specific orchard management system, resource availability, and commercial objectives, ranging from the high output 'Coratina' to the highly efficient 'Arbequina' and 'Arbosana'. Discussion This superior vegetative expansion suggests that 'Coratina' possesses a genetic constitution that allows for more efficient resource capture and biomass accumulation under the moderate salinity and low fertility of the experimental soil. This aligns with its known reputation as a vigorous and resilient cultivar in Mediterranean environments[ 23 ]. This is characteristic of their genetic predisposition for lower vigor, which is a key trait selected for high-density planting systems to reduce inter-tree competition[ 24 ]. The lower vigor cultivars, 'Arbequina' and 'Arbosana', exhibited shorter annual shoot elongation and smaller leaf sizes. This reduced vegetative effort can be interpreted as a conservative strategy, allocating resources away from excessive growth and potentially towards other functions like maintenance or reproduction under stress conditions[ 25 ]. The intermediate values for 'Maraqi' further confirm its middle position in terms of vegetative growth potential in this challenging environment. The consistent growth patterns across both seasons, with 'Coratina' > 'Maraqi' > 'Arbequina'/'Arbosana', highlight the strong genotypic control over vegetative growth traits. However, the observed numerical increase in all growth parameters from the first to the second season for each cultivar suggests a positive response to improved root establishment and perhaps more favorable climatic conditions in the second year, a common phenomenon in young orchards[ 13 ]. This suggests a high investment in the photosynthetic apparatus, which is consistent with its observed supports its high superior vegetative growth and likely carbohydrate demand for both growth and fruit production[ 26 ]. A lower chlorophyll content can be interpreted as a conservative or protective strategy under stress. It may reduce light absorption capacity, thereby minimizing the production of reactive oxygen species (ROS) when the photosynthetic machinery is compromised by drought or salinity, a common stress-response mechanism[ 27 ]. This indicates highly effective stomatal regulation and possibly superior osmotic adjustment, allowing these cultivars to avoid dehydration and maintain physiological function under soil water deficit[ 28 ]. The accumulation of the amino acid Proline is a well-established biochemical response to osmotic stress (salinity or drought) and serves as a reliable biomarker for the severity of abiotic stress perception within the plant[ 29 ]. Their effective stress-avoidance mechanisms such as stomatal control apparently prevented the severe cellular dehydration that triggers major osmolyte synthesis. This suggests they were successful in minimizing physiological disruption, thereby reducing the metabolic cost of stress acclimation. 'Arbosana' showed an intermediate proline accumulation, reflecting a moderate level of perceived stress[ 30 ]. This prolific flowering is a known characteristic of this cultivar and represents a high-investment strategy to ensure reproductive success by saturating the environment with potential fruit sites[ 31 ]. The significantly higher Gynosterility (flower abortion) rate in 'Coratina' indicates that a substantial portion of its prolific flower production was defective and incapable of setting fruit. This phenomenon is well-documented in some high-flowering-intensity olive cultivars and is often exacerbated by abiotic stresses, which can disrupt floral organ development[ 32 ]. This aligns with the concept of a "flowering-fruit set trade-off" observed in many fruit tree species[ 33 ]. This metric is critical for assessing the economic and environmental resource use efficiency of an orchard system[ 34 ]. ). This is a well-known characteristic of this cultivar, which is valued for its high pulp-to-pit ratio and oil yield[ 35 ] The amount of oil that is present in the fruits, the oil content at harvest, is the defining feature of the quality and economic viability of olive oil cultivars. Our analytical research indicates that the genotype of olive oil cultivars shows considerable and reliable variation for oil content under the combined influence of soil quality and water availability in newly developed soils. The results clearly demonstrate that 'Coratina' has a greater concentration of oils by weight (Fig. 6 ), strongly supporting its long held view of being among the best oil-producing cultivars[ 23 ]. As such, because of the genetically determined high-oil characteristics of 'Coratina' and its demonstrated fruit size advantages and increased oil production per tree, this cultivar is an exceptional candidate to enhance the total production of gross oil with respect to area planted, provided that space or resources do not limit the number of trees that can be established. This is consistent with the historical use of 'Coratina' in large, extensive plantings in Southern Italy, where the robust growth and high oil production of the cultivar have been cultivated. Oil concentrations measured for ‘Arbequin’ and ‘Maraqi’ are both intermediate in statistical terms, but within the bounds of what is commercially viable for both cultivars. Therefore, we can consider them both reliable for producing oil under marginal growing conditions. However, 'Arbosana' must be evaluated more thoroughly. ‘Arbosana’ has been grouped with ‘Arbequina’ and ‘Maraqi', but exhibits a tendency to cluster with ‘Coratina’ in two seasons, indicating potential for higher oil content. This indicates an agronomic opportunity to identify a cultivar capable of producing large amounts of oil from a small tree with weak vigor across multiple sites and seasons. This is one of the primary driving forces behind the global adoption of ‘Arbosana’ for olive production in high-density (‘super high-density’) production systems, where maximum yield efficiency of canopies and land area, rather than tree-by-tree productivity, are the priorities of production[ 36 ]. Thus, when data related to productive capacity, resource-use efficiency, and plant physiology, we draw one conclusion that unites these concepts: no one cultivar is superior; rather there is a distinct trade-off between resource-use efficiency and productive capacity as determined by the physiological strategies of each cultivar. Choosing the best cultivar is not just about picking the one that has the greatest oil levels; there is a strategic aspect in looking at how the selected cultivar will integrate to the other management goals and resources of the orchard. Conclusion This study highlights the contrasting adaptive strategies and agronomic performance of four olive cultivars, Coratina’, ‘Arbequina’, ‘Arbosana’, and ‘Maraqi’ under newly reclaimed soils. Results reveal a trade-off between vegetative growth, stress response, and yield efficiency, underscoring the need for context-specific cultivar selection. ‘Coratina’ showed vigorous growth, high yield, and superior oil content, but at the cost of severe physiological stress, making it productive yet risk-prone. In contrast, Arbequina’ and ‘Arbosana’ adopted a resource-efficient strategy, combining compact growth with high yield efficiency and stable water status, suiting them to high-density, intensive systems. ‘Maraqi’ offered resilience through superior water retention and minimal stress indicators, making it best suited for drought-prone or uncertain environments. No cultivar is universally superior. Choice depends on production goals and resource availability: Coratina’ for maximum yield and oil, ‘Arbequina’/‘Arbosana’ for efficiency-driven systems, and ‘Maraqi’ for stability under water-limited conditions. These findings provide a framework for sustainable olive expansion in marginal lands, with future studies needed on long-term performance under water stress. Declarations Ethics approval and consent to participate The authors confirmed that the institutional committee and licensing committee approved the experiments, including all relevant details and that all experiments have been performed in accordance with specified named guidelines and regulations. Consent for publication: The article contains no such material that may be unlawful, defamatory, or which would, if published, in any way whatsoever, violate the terms and conditions as laid down in the agreement. Availability of data and material: The data generated and/or analysed during the current study are available per request to the corresponding author. Competing interests: The authors declare that they have no conflict of interest in the publication. Funding: This research did not receive any external funding. Authors' contributions: Conceptualization HFA and AEH; Data curation HFA, and ANA; Formal analysis HFA, AEH, IAE, and ANA; Investigation AEH, and ANA; Methodology HFA and ANA; Project administration AMA; Resources IAE, and ANA; Software HFA, and ANA; Supervision AEH; Validation AEH, and ANA; Visualization HFA, AEH, IAE, and ANA; Writing - original draft AEH; Writing - review and editing AEH. All authors read and approved the final manuscript. References Fraga, H., Moriondo, M., Leolini, L. & Santos, J. A. Mediterranean olive orchards under climate change: A review of future impacts and adaptation strategies. Agronomy 11 , 56 (2020). Kavvadias, V. & Koubouris, G. Sustainable soil management practices in olive groves. in Soil fertility management for sustainable development 167–188 (Springer, 2019). Brito, C., Dinis, L.-T., Moutinho-Pereira, J. & Correia, C. M. Drought stress effects and olive tree acclimation under a changing climate. Plants 8 , 232 (2019). Lo Bianco, R., Proietti, P., Regni, L. & Caruso, T. Planting systems for modern olive growing: Strengths and weaknesses. Agriculture 11 , 494 (2021). Guermazi, E., Wali, A. & Ksibi, M. Combining remote sensing, SPAD readings, and laboratory analysis for monitoring olive groves and olive oil quality. Precision Agriculture 25 , 65–82 (2024). Karimi, S., Rahemi, M., Rostami, A. A. & Sedaghat, S. Drought effects on growth, water content and osmoprotectants in four olive cultivars with different drought tolerance. International Journal of Fruit Science 18 , 254–267 (2018). Spormann, S. et al. Accumulation of proline in plants under contaminated soils—are we on the same page? Antioxidants 12 , 666 (2023). Gucci, R. et al. Fruit growth, yield and oil quality changes induced by deficit irrigation at different stages of olive fruit development. Agricultural Water Management 212 , 88–98 (2019). Camposeo, S., Vivaldi, G. A., Montemurro, C., Fanelli, V. & Cunill Canal, M. Lecciana, a new low-vigour olive cultivar suitable for super high density orchards and for nutraceutical EVOO production. Agronomy 11 , 2154 (2021). Molinu, M. G. et al. Looking for Typical Traits in Monovarietal VOOs According to Their Phenolic Composition. Foods 13 , 3425 (2024). ELSORADY, M. E., MOHAMED, A. S. & MOHAMED, E. S. Influence of organic fertilization and irrigation on quality of maraqi cultivar virgin olive oil. Egyptian Journal of Agricultural Research 92 , 709–728 (2014). Peel, M. C., Finlayson, B. L. & McMahon, T. A. Updated world map of the Köppen-Geiger climate classification. Hydrology and earth system sciences 11 , 1633–1644 (2007). Fernández-Escobar, R. Olive nutritional status and tolerance to biotic and abiotic stresses. Frontiers in plant science 10 , 1151 (2019). Rosati, A., Wolz, K. J., Murphy, L., Ponti, L. & Jose, S. Modeling light below tree canopies overestimates net photosynthesis and radiation use efficiency in understory crops by averaging light in space and time. Agricultural and Forest Meteorology 284 , 107892 (2020). Křížová, K. et al. Using a single-board computer as a low-cost instrument for SPAD value estimation through colour images and chlorophyll-related spectral indices. Ecological Informatics 67 , 101496 (2022). Slama, A., Mallek-Maalej, E., Ben Mohamed, H., Rhim, T. & Radhouane, L. A return to the genetic heritage of durum wheat to cope with drought heightened by climate change. PLoS One 13 , e0196873 (2018). Bates, L. S., Waldren, R. P. A. & Teare, I. D. Rapid determination of free proline for water-stress studies. Plant and soil 39 , 205–207 (1973). Seifi, E., Guerin, J., Kaiser, B. & Sedgley, M. Flowering and fruit set in olive: a review. Iran. J. Plant Physiol 5 , 1263–1272 (2015). Montemurro, C., Dambruoso, G., Bottalico, G. & Sabetta, W. Self-incompatibility assessment of some Italian olive genotypes (Olea europaea L.) and cross-derived seedling selection by SSR markers on seed endosperms. Frontiers in plant science 10 , 451 (2019). Famiani, F. et al. Deflowering as a Tool to Accelerate Growth of Young Trees in Both Intensive and Super-High-Density Olive Orchards. Agronomy 12 , 2319 (2022). Feldsine, P., Abeyta, C. & Andrews, W. H. AOAC INTERNATIONAL Methods Committee Guidelines for Validation of Qualitative and Quantitative Food Microbiological Official Methods of Analysis. Journal of AOAC INTERNATIONAL 85 , 1187–1200 (2002). Famiani, F. et al. Harvesting system and fruit storage affect basic quality parameters and phenolic and volatile compounds of oils from intensive and super-intensive olive orchards. Scientia Horticulturae 263 , 109045 (2020). Clodoveo, M. L. et al. Research and Innovative Approaches to Obtain Virgin Olive Oils with a Higher Level of Bioactive Constituents. in Olive and Olive Oil Bioactive Constituents 179–215 (Elsevier, 2015). doi:10.1016/B978-1-63067-041-2.50013-6. Maris, S. C., Teira-Esmatges, M. R., Arbonés, A. & Rufat, J. Effect of irrigation, nitrogen application, and a nitrification inhibitor on nitrous oxide, carbon dioxide and methane emissions from an olive (Olea europaea L.) orchard. Science of The Total Environment 538 , 966–978 (2015). Sobreiro, J., Patanita, M. I., Patanita, M. & Tomaz, A. Sustainability of High-Density Olive Orchards: Hints for Irrigation Management and Agroecological Approaches. Water 15 , 2486 (2023). Rosati, A., Lodolini, E. M. & Famiani, F. From flower to fruit: fruit growth and development in olive (Olea europaea L.)—a review. Front. Plant Sci. 14 , 1276178 (2023). El Yamani, M. & Cordovilla, M. D. P. Tolerance Mechanisms of Olive Tree (Olea europaea) under Saline Conditions. Plants 13 , 2094 (2024). Ben Abdallah, M. et al. Unraveling physiological, biochemical and molecular mechanisms involved in olive (Olea europaea L. cv. Chétoui) tolerance to drought and salt stresses. Journal of Plant Physiology 220 , 83–95 (2018). Ben Abdallah, M., Methenni, K., Taamalli, W. & Ben Youssef, N. Post-stress recovery from drought and salinity in olive plants is an active process associated to physiological and metabolic changes. Acta Physiol Plant 46 , 120 (2024). Poury, N., Seifi, E. & Alizadeh, M. Effects of Salinity and Proline On Growth and Physiological Characteristics of Three Olive Cultivars. Gesunde Pflanzen 75 , 1169–1180 (2023). Camarero, M. C. et al. Characterization of Transcriptome Dynamics during Early Fruit Development in Olive (Olea europaea L.). IJMS 24 , 961 (2023). Silva, E. et al. Olive Yield and Physicochemical Properties of Olives and Oil in Response to Nutrient Application under Rainfed Conditions. Molecules 28 , 831 (2023). Garnier, E. et al. Leaf longevity and structure, fruit mass and phenology in 52 cultivated varieties and wild accessions of olive. Functional Ecology 1365-2435.70012 (2025) doi:10.1111/1365-2435.70012. Trentacoste, E. R. et al. Effect of regulated deficit irrigation during the vegetative growth period on shoot elongation and oil yield components in olive hedgerows (cv. Arbosana) pruned annually on alternate sides in San Juan, Argentina. Irrig Sci 37 , 533–546 (2019). Cecchi, L. et al. Virgin Olive Oil By-Product Valorization: An Insight into the Phenolic Composition of Olive Seed Extracts from Three Cultivars as Sources of Bioactive Molecules. Molecules 28 , 2776 (2023). Tous, J. The influence of growing region and cultivar on olives and olive oil characteristics and on their functional constituents. in Olives and Olive Oil as Functional Foods (eds Shahidi, F. & Kiritsakis, A.) 45–80 (Wiley, 2017). doi:10.1002/9781119135340.ch4. Additional Declarations No competing interests reported. Supplementary Files Discussion.docx Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 23 Feb, 2026 Reviews received at journal 23 Feb, 2026 Reviews received at journal 11 Feb, 2026 Reviews received at journal 10 Feb, 2026 Reviews received at journal 10 Feb, 2026 Reviewers agreed at journal 02 Feb, 2026 Reviewers agreed at journal 01 Feb, 2026 Reviewers agreed at journal 29 Jan, 2026 Reviewers agreed at journal 29 Jan, 2026 Reviewers agreed at journal 29 Jan, 2026 Reviewers agreed at journal 27 Jan, 2026 Reviewers agreed at journal 27 Jan, 2026 Reviewers invited by journal 27 Jan, 2026 Editor assigned by journal 27 Jan, 2026 Editor invited by journal 27 Jan, 2026 Submission checks completed at journal 22 Jan, 2026 First submitted to journal 22 Jan, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8662502","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":581793866,"identity":"da4e5914-8842-4474-9201-ebb1822656da","order_by":0,"name":"Abd El-wahed N. Abd El-wahed","email":"","orcid":"","institution":"Al Azhar University","correspondingAuthor":false,"prefix":"","firstName":"Abd","middleName":"El-wahed N. Abd","lastName":"El-wahed","suffix":""},{"id":581793867,"identity":"93df55ad-c721-43c8-930f-b078ef234b93","order_by":1,"name":"Ibrahim A. Elnaggar","email":"","orcid":"","institution":"Al Azhar University","correspondingAuthor":false,"prefix":"","firstName":"Ibrahim","middleName":"A.","lastName":"Elnaggar","suffix":""},{"id":581793868,"identity":"041c2775-cc59-4a21-a99b-8f23d426d9c4","order_by":2,"name":"Hosny F. Abdel-Aziz","email":"","orcid":"","institution":"Al Azhar University","correspondingAuthor":false,"prefix":"","firstName":"Hosny","middleName":"F.","lastName":"Abdel-Aziz","suffix":""},{"id":581793869,"identity":"70ae96fb-ddf9-4fd7-b24f-b13494a07132","order_by":3,"name":"Ashraf E. Hamdy","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABCElEQVRIie3PMUsDMRTA8VcK6ZJy67ul9xXeIRwelParRA5uOnQQpNCqKUImwY/gV1AEcbwSSJcT1+vc1cHi0lvUVNwk0NtE8oeEEPjxEgCf70/G7RruDt0SOvL7ivYguV2MidaE034kuHlevE/EcBzcXm82zdPoBHpXjwiTcyfB+jgLK5F30fQfMKyyVHJzhlAt3WNqTuF8qxmY/h3GqkuARYIdZZwieqkOGik+eWT4enukLgmiV0s+3ITKIgmlKJEMZ7hQ2k7hlsiZk8R1kaRSZBSbPEnnakmM56eHwpROMrAPW0kxGg+0Xq8aNaWgp+/rt9mF+/u/YrtNgG5Bfmozxefz+f55XzfsUVz8jiJWAAAAAElFTkSuQmCC","orcid":"","institution":"Al Azhar University","correspondingAuthor":true,"prefix":"","firstName":"Ashraf","middleName":"E.","lastName":"Hamdy","suffix":""}],"badges":[],"createdAt":"2026-01-21 17:38:58","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8662502/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8662502/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":101752155,"identity":"9b310240-4ae8-4415-b6cb-32128cd68c9a","added_by":"auto","created_at":"2026-02-03 10:25:46","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":323094,"visible":true,"origin":"","legend":"\u003cp\u003eCanopy volume (A), shoot length (B), and leaf area (C) of four olive cultivars in 2024 and 2025 growing seasons. Bars within a season followed by the same letter are not significantly different (\u003cem\u003ep\u003c/em\u003e≤ 0.05) according to Duncan’s test.\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8662502/v1/ba9a0a7a1ed44691222db51d.jpeg"},{"id":101433642,"identity":"c23df9aa-1889-418c-b205-026413261e57","added_by":"auto","created_at":"2026-01-29 15:57:31","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":384245,"visible":true,"origin":"","legend":"\u003cp\u003eTotal leaf chlorophyll (SPAD) (A), relative water content (RWC, %) (B), and leaf proline content (C) of four olive cultivars in 2024 and 2025 growing seasons. Bars within a season followed by the same letter are not significantly different (p ≤ 0.05) according to Duncan’s test.\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8662502/v1/eb76f942a5e5cafdd530b6c8.jpeg"},{"id":101433646,"identity":"b2d23e12-dbd7-4731-9df4-da7bdbd4e7f4","added_by":"auto","created_at":"2026-01-29 15:57:32","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":710512,"visible":true,"origin":"","legend":"\u003cp\u003eThe inflorescence length (A), number of flowers per inflorescence (B), Gynosterility % (C), and fruit set % of four olive cultivars in 2024 and 2025 growing seasons. Bars within a season followed by the same letter are not significantly different (p ≤ 0.05) according to Duncan’s test.\u003c/p\u003e","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8662502/v1/68673c12703117f4c1a8c854.jpeg"},{"id":101433637,"identity":"5aa10814-9a91-4bef-aa41-b9221835bd6f","added_by":"auto","created_at":"2026-01-29 15:57:28","extension":"jpeg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":332915,"visible":true,"origin":"","legend":"\u003cp\u003eFruit yield (kg/tree) (A), Yield Efficiency (kg fruit /m³ of canopy) (B), of four olive cultivars in 2024 and 2025 growing seasons. Bars within a season followed by the same letter are not significantly different (p ≤ 0.05) according to Duncan’s test.\u003c/p\u003e","description":"","filename":"floatimage4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8662502/v1/8854bd9564588f6e086bf924.jpeg"},{"id":101433645,"identity":"2d8d937e-0623-48b3-a32e-fe4ed954bd1e","added_by":"auto","created_at":"2026-01-29 15:57:32","extension":"jpeg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":355522,"visible":true,"origin":"","legend":"\u003cp\u003eFruit weight (g) (A), and fruit volume (cm³) (B), of four olive cultivars in 2024 and 2025 growing seasons. Bars within a season followed by the same letter are not significantly different (p ≤ 0.05) according to Duncan’s test.\u003c/p\u003e","description":"","filename":"floatimage5.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8662502/v1/aa6e5489711300245750933c.jpeg"},{"id":101433641,"identity":"eb1c3f1e-b49e-4729-838e-8581aa569e1e","added_by":"auto","created_at":"2026-01-29 15:57:31","extension":"jpeg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":178653,"visible":true,"origin":"","legend":"\u003cp\u003eFruit oil content %, of four olive cultivars in 2024 and 2025 growing seasons. Bars within a season followed by the same letter are not significantly different (p ≤ 0.05) according to Duncan’s test.\u003c/p\u003e","description":"","filename":"floatimage6.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8662502/v1/ca6fb099a79b055509b42b59.jpeg"},{"id":101756207,"identity":"d1880c36-198b-48dc-9e12-7c07df72137b","added_by":"auto","created_at":"2026-02-03 10:56:58","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3218834,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8662502/v1/0a06bb59-427b-4939-8d89-0788f59ca482.pdf"},{"id":101433643,"identity":"f96f8973-5c6c-44e6-a560-d9214c9c4b05","added_by":"auto","created_at":"2026-01-29 15:57:31","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":18974,"visible":true,"origin":"","legend":"","description":"","filename":"Discussion.docx","url":"https://assets-eu.researchsquare.com/files/rs-8662502/v1/9d36a803e5687a5fa9b757da.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"A Comparative Study of the Growth, Yield, and Physiological Responses of Arbosana, Arbequina, Coratina, and Maraqi Olive Cultivars","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eThe olive (\u003cem\u003eOlea europaea\u003c/em\u003e L.) has a global reach and reflects a growing trend of olive cultivation into arid and semi-arid areas due to demand for its oil and climate resilient agriculture[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. In this new context, often associated with salinity, low organic matter, low fertility, and poor water retention, new reclaimed soils represent a frontier for agricultural development, but it is also a significant agronomic opportunity[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. The olive tree is recognized for its drought tolerant and tolerant of marginal conditions, therefore it is well suited to these new lands[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. However, its widely touted resilience is a general species characteristic that belies substantial genotypic variation. Thus, choice of cultivar is the most important aspect of whether olive orchards will establish and produce successfully in these high-stress environments[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe genotypic response to abiotic stress is a complex function of physiological, morphological and biochemical acclimatization. Recommended cultivars for marginal lands not only need to survive but also need to demonstrate productivity sustainability and fruit quality. This entails evaluating cultivars holistically beyond yield components when assessing physiological measures of stress response. Chlorophyll content determined by SPAD readings reflects photosynthetic ability and nitrogen status, which is often impaired under stress[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Relative Water Content (RWC) is the first measure of a plant's water balance and a drought avoidance measure[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Accumulation of osmolytes, specifically proline, has been well-described as a biochemical response to osmotic stress, and acts as a marker for the degree of abiotic pressure and the plant's response to lessen the effects of the stress[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. At the same time, agronomic performance determined by vegetative growth (canopy volume, shoot growth), reproductive performance (fruit set, yield efficiency) and final fruit quality (oil content) determine the sustainability of a given cultivar [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThis study aims to compare the performance of four distinct cultivars that appear potential candidates for intensive plantings: Arbosana, Arbequina, Coratina, and Maraqi. Arbequina and Arbosana are Spanish cultivars that are the basis for most high density and super high-density planting systems throughout the world and are desirable due to their lower vigor and high early productivity[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Coratina, an Italian cultivar, is aesthetically appealing for its high polyphenolic nutrient content but has higher vigor and may have different physiological resource requirements and tolerances for stress[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Finally, Maraqi, which is primarily cultivated in North Africa and the Middle East, is expected to have inherent adaptive properties for heat and drought stress[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] but is not well represented in international scientific literature. It should be noted that the cultivar performance rank is not permanent, but it is related to whatever the genotype-by-environment (G\u0026times;E) interaction entails. A cultivar that thrives within the traditional Mediterranean basins may have poor performance potential in the edapho-climatic conditions imposed through the reclamation of new soils, where least constraints like salinity and lower water holding capacity are used to classify the soils.\u003c/p\u003e \u003cp\u003eThere is a marked shortage of rigorous, multi-factorial comparative studies that compare these cultivars directly under the same stress levels associated with newly reclaimed land. Most existing studies are in established growing areas or only monitor a limited number of parameters. A study that combines physiological stress biomarkers, along with agronomic and pomological information, will be important for making sound, evidence-based recommendations to growers. This study was, therefore, developed to provide the ultimate comparison of the adaptive and productive performance of Arbosana, Arbequina, Coratina and Maraqi cultivars of olives grown in new reclaimed soils. We hypothesized that the four cultivars would exhibit distinct adaptive syndromes, resulting in significant trade-offs between vegetative vigor, physiological stress tolerance, and reproductive efficiency under the conditions of newly reclaimed soil.\u003c/p\u003e"},{"header":"2. Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Site Description and Experimental Orchard Establishment\u003c/h2\u003e \u003cp\u003eThe study was conducted over two consecutive growing seasons (2024 and 2025) at a private orchard located at Wadi Al-Natrun region (Coordinates: approximately 30\u0026deg;24'01.7\"N 30\u0026deg;02'20.6\" E), El- Behera Governorate, Egypt, planted in sandy soil at 4 \u0026times; 6 m apart. The region is characterized by an arid and semi-arid climate according to the K\u0026ouml;ppen-Geiger climate classification[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Meteorological data recorded by an onsite weather station showed average maximum temperatures of 35.8\u0026deg;C in summer and 19.5\u0026deg;C in winter, with an average annual rainfall of \u0026lt;\u0026thinsp;50 mm, necessitating a full irrigation regime. The orchard was established in early 2015. Ten-year-old, own-rooted cuttings, uniform trees of the four olive cultivars (Arbosana\u0026rsquo;, \u0026lsquo;Arbequina\u0026rsquo;, \u0026lsquo;Coratina\u0026rsquo;, and \u0026lsquo;Maraqi\u0026rsquo;) were sourced from a certified commercial nursery. The experimental design was a Randomized Complete Block Design (RCBD) with four blocks (replications), each containing four rows of trees (one row per cultivar). Each experimental unit (plot) consisted of 5 trees, with the three central trees used for data collection to avoid edge effects, totaling 16 plots and 80 trees.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2. Agronomic Management\u003c/h2\u003e \u003cp\u003eA common agronomic management practice was applied to all cultivars. Drip irrigation was employed using two pressure-compensating drippers (4 L h⁻\u0026sup1;) per tree. Fertilization followed soil analysis recommendations and standard practices for young olive orchards[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Annually, 1000 g N, 500 g P\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e and 900 g K\u003csub\u003e2\u003c/sub\u003eO per tree were applied through the fertigation system.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Data Collection and Measurements\u003c/h2\u003e \u003cp\u003eData were collected on the three central trees of each plot during the two study seasons. Moreover, the plant materials were collected from a private orchard with the full permission of the landowner.\u003c/p\u003e \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e \u003ch2\u003e2.3.1. Vegetative Growth Parameters:\u003c/h2\u003e \u003cp\u003e \u003cb\u003eCanopy Volume (m\u0026sup3;)\u003c/b\u003e: Estimated using the formula for a prolate spheroid: V = (4/3) \u0026times; π \u0026times; (H/2) \u0026times; (W/2)\u0026sup2;, where H is the canopy height and W is the mean canopy diameter [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eShoot Length (cm)\u003c/strong\u003e \u003cp\u003eTwenty well-developed, one-year-old shoots per tree were tagged, and their elongation was measured at the end of the growing season.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eLeaf Area (cm\u0026sup2;)\u003c/strong\u003e \u003cp\u003eThe area of 50 mature, fully expanded leaves per tree was measured using a portable leaf area meter (LI-3000C, LI-COR Biosciences).\u003c/p\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section3\"\u003e \u003ch2\u003e2.3.2. Physiological Parameters:\u003c/h2\u003e \u003cp\u003e \u003cb\u003eLeaf Chlorophyll Content\u003c/b\u003e: Estimated using a portable SPAD-502Plus chlorophyll meter (Konica Minolta). Readings were taken on clear days between 10:00 and 12:00 on 30 sun-exposed, mature leaves per tree[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003cb\u003eRelative Water Content (RWC%)\u003c/b\u003e: Measured according to the method of Slama et al.[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Ten leaf discs per tree were sampled, fresh weight (FW) recorded, turgid weight (TW) obtained after floating on distilled water for 24h in the dark, and dry weight (DW) measured after oven-drying at 70\u0026deg;C to constant weight. RWC was calculated as: RWC (%) = [(FW - DW) / (TW - DW)] \u0026times; 100.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eLeaf Proline Content (\u0026micro;mol g⁻\u0026sup1; FW)\u003c/strong\u003e \u003cp\u003eQuantified using the acid-ninhydrin method described by Bates et al. [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Proline was extracted from 0.5 g of fresh leaf tissue and its concentration determined spectrophotometrically at 520 nm using L-proline as a standard.\u003c/p\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section3\"\u003e \u003ch2\u003e2.3.3. Flowering characteristic\u003c/h2\u003e \u003cp\u003e \u003cb\u003eGenetic Sterilities\u003c/b\u003e \u003c/p\u003e \u003cp\u003eThe fruit set in olive trees is mainly determined by the following two traits: pistil abortion (female sterility) and self-incompatibility[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. In our study, we evaluated these two forms of genetic sterility using four cultivars: 'Arbosana', 'Arbequina', 'Coratina', and 'Maraqi' grown for two consecutive seasons (2024\u0026ndash;2025). To determine gynosterility, we sampled 60 inflorescences per tree at the time of blooming from three separate canopy heights (0.5\u0026ndash;1.0 m, 1.0\u0026ndash;1.5 m, and 1.5\u0026ndash;2.0 m). To assess self-incompatibility, we followed the procedures established in [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. We used 50 inflorescences from each tree, divided between both east and west sides of the canopy. The inflorescences in one group were covered with non-woven bags prior to anthesis thus that they could only self-pollinate by wind-assisted movement. The other group's inflorescences were left exposed for wind-assisted cross-pollination. After veraison, fruit set was assessed for both groups. In addition to assessing the above two forms of genetic sterility, we also monitored the blooming period of the inflorescences in the open-pollination group on a weekly basis. We defined the different phenological stages based on the percentages of inflorescences open as follows: 10% (beginning), 50% (full bloom), and 90% (end of bloom).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003e2.3.4. Yield and Fruit Characteristics:\u003c/h2\u003e \u003cp\u003e \u003cstrong\u003eFruit Yield (kg tree⁻\u0026sup1;)\u003c/strong\u003e \u003cp\u003eThe total fruit weight from each tree was recorded at commercial harvest maturity (determined by a fruit maturity index).\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eYield Efficiency (kg m⁻\u0026sup3;)\u003c/strong\u003e \u003cp\u003eCalculated as the ratio of fruit yield to canopy volume[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eFruit physical properties\u003c/strong\u003e \u003cp\u003eA random sample of 50 fruits per tree was used to measure fruit weight, length, and width using a digital caliper. The pulp-to-pit ratio was determined by manually separating and weighing the components.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003eOil Content (% on dry weight)\u003c/b\u003e:\u003c/p\u003e \u003cp\u003eTo determine the total amount of extracted oil from the harvested fruit, an average sample weighing 100 g was obtained from each replicate. Each sample was extracted using a Soxhlet extractor with petroleum ether (boiling between 40 and 60\u0026deg;). The length of time for each extraction was 6 hours. Any petroleum ether remaining in the oil/solvent mixture was removed using a rotary evaporator (Heidolph, Germany) set at 40\u0026deg;. The remaining oil was brought to a temperature of 105\u0026deg; using an oven and dried for 1 hour to eliminate water and/or residual petroleum ether prior to recording the final weight of the oil collected from the extracted fruit[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Finally, an oil yield (kg/tree) was calculated for each tree based on the percentage of oil collected from the extracted sample divided by the tree's total harvest weight.\u003c/p\u003e \u003cp\u003e \u003cb\u003eStatistical Analysis\u003c/b\u003e \u003c/p\u003e \u003cp\u003eAll data were subjected to one-way Analysis of Variance (ANOVA) using the general linear model (GLM) procedure in co-stat software (version. 6.0). Mean separation was performed using Duncan\u0026rsquo;s Multiple Range Test (DMRT) at a significant level of \u003cb\u003ep\u003c/b\u003e\u0026thinsp;\u0026le;\u0026thinsp;0.05. All assumptions of ANOVA, including normality and homogeneity of variances were tested and met.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"3. Results","content":"\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e3.1. Vegetative Growth Performance\u003c/h2\u003e \u003cp\u003eThe analysis of vegetative growth parameters revealed significant differences among the four olive cultivars in their adaptation to the conditions of the newly reclaimed soil over the two study seasons. The genotype by environment interaction was also significant, indicating that the cultivars responded differently to the inter annual variations in climatic conditions.\u003c/p\u003e \u003cp\u003eCanopy volume, a primary indicator of tree vigor and establishment, data in (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA) showed a clear and consistent hierarchy among the cultivars. 'Coratina' demonstrated the most robust growth, achieving a significantly larger canopy volume than all other cultivars. Conversely, 'Arbequina' and one of the 'Arbosana' trees exhibited the most constrained growth, consistently registering the smallest canopy volumes and belonging to the lowest statistical grouping (Group D). The 'Maraqi' cultivar displayed intermediate vigor, its canopy volume not being statistically different from the larger 'Arbosana' plot in one season and forming an intermediate group (B/C) in the other. This indicates a moderate adaptive capacity in terms of vegetative development.\u003c/p\u003e \u003cp\u003eData in (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB and C) clearly showed that shoot length and leaf area data corroborated the findings on canopy volume, reinforcing the vigor ranking of the cultivars. 'Coratina' again consistently produced the longest shoots and the largest leaves, significantly outperforming the other cultivars. This enhanced photosynthetic machinery (larger leaf area) likely contributes to its greater biomass production (canopy volume).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003ePhysiological Responses to Abiotic Stress\u003c/b\u003e \u003c/p\u003e \u003cp\u003eThe physiological parameters measured provide a critical lens into the underlying strategies employed by each cultivar to cope with the abiotic stresses likely including salinity, heat, and water deficit inherent to the newly reclaimed soil. The significant differences observed highlight distinct adaptive mechanisms.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Leaf Chlorophyll Content\u003c/h2\u003e \u003cp\u003eResults in (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA) showed that leaf chlorophyll content (SPAD) concentrations, an indicator of photosynthetic potential and nitrogen status, revealed a clear genotypic gradient. 'Coratina' consistently maintained the highest chlorophyll concentration, significantly exceeding the other cultivars. This attribute can be advantageous for productivity but may also increase the risk of photo-oxidative damage under extreme light and temperature stress. Conversely, 'Maraqi' registered the lowest SPAD values in both seasons. 'Arbequina' and 'Arbosana' exhibited intermediate chlorophyll levels, positioning them between the two extremes.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003e2.2. Plant Water Status\u003c/h2\u003e \u003cp\u003eRelative water content (RWC%) is a primary indicator of a plant's hydration and its ability to maintain water balance. The data in (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eB) uncovered a striking contrast in water relations strategies among the cultivars. 'Maraqi' and 'Arbequina' demonstrated the strongest ability to maintain tissue hydration, consistently achieving the highest RWC values and forming the top statistical group. This trait is a key marker of drought avoidance. In stark contrast, 'Coratina' exhibited the lowest RWC values, significantly lower than all other cultivars. This suggests a different strategy, often termed drought tolerance. 'Coratina' appears to continue transpiring and growing even as soil water decreases, enduring lower tissue water potential. This strategy relies on a robust root system and cellular-level tolerance to dehydration but carries a higher risk of hydraulic failure under prolonged or severe drought. 'Arbosana' showed an intermediate RWC, indicating a moderate water conservation ability.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Proline content of leaf\u003c/h2\u003e \u003cp\u003eThe results in (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eC) showed that 'Coratina' accumulated proline to a significantly greater extent than all other cultivars in both seasons. This markedly high concentration signifies that 'Coratina' was experiencing the highest level of physiological stress among cultivars. Proline functions as a compatible osmolyte for osmotic adjustment, a stabilizer of proteins and membranes, and a ROS scavenger. The high investment in this pathway is consistent with its tolerance strategy but also highlights the significant metabolic cost associated with its growth under these conditions. Conversely, 'Maraqi' and 'Arbequina' maintained the lowest proline levels. This finding is critical, as it aligns that aligns perfectly with their high RWC.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"3. Reproductive Development and Yield Formation","content":"\u003cp\u003eThe investigation of reproductive parameters revealed profound and statistically significant differences (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) among the cultivars, revealing distinct reproductive strategies and their efficacy in the challenging environment of newly reclaimed soil.\u003c/p\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003e3.1. Flowering Capacity and Quality\u003c/h2\u003e \u003cp\u003eA clear hierarchy was observed in flowering traits. 'Coratina' consistently produced the longest inflorescences and the highest number of flowers per inflorescence, significantly outperforming the other three cultivars (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eA and B). Conversely, 'Arbosana' and 'Arbequina' exhibited more conservative flowering, with significantly shorter rachises and fewer flowers per inflorescence. 'Maraqi' consistently displayed an intermediate flowering capacity, positioned between the two extremes. However, quantity was inversely related to quality. The other cultivars maintained significantly lower and statistically similar gynosterility rates, with 'Maraqi' showing a tendency toward higher abortion in the second season, suggesting a potential sensitivity to specific environmental conditions.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003e3.2. Fruit Set %\u003c/h2\u003e \u003cp\u003eThe culmination of flowering and pollination success is reflected in the fruit set (%) data. Here, the strategy of the different cultivars becomes starkly evident. 'Arbequina' and 'Arbosana' achieved the highest fruit set percentages, successfully converting a large proportion of their fewer flowers into developing fruits (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eC). This high efficiency is a hallmark of modern cultivars bred for intensive systems and indicates effective pollination and good carbohydrate availability during the critical fruit set period[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Despite its immense number of flowers, 'Coratina' registered the lowest fruit set percentage by a significant margin. This is a direct consequence of its high gynosterility and likely also due to intense internal competition for carbohydrates among its enormous number of fruitlets, leading to a high rate of abscission (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eD). 'Maraqi' demonstrated a fruit set percentage that was intermediate but statistically lower than the efficient setters, indicating a moderate conversion efficiency.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec18\" class=\"Section2\"\u003e \u003ch2\u003e3.3. Fruit yield (kg/tree)\u003c/h2\u003e \u003cp\u003eThe interplay between vegetative growth (as represented by canopy volume from the previous analysis) and reproductive output defines the economic productivity of the orchard. 'Coratina' achieved the highest absolute Yield (kg/tree) (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eA), a direct result of its massive vegetative structure and its strategy of compensating for low fruit set with an exceptionally high initial flower number. Its large canopy was able to support this considerable fruit load. In contrast, the lower-vigor cultivars 'Arbequina' and 'Arbosana' produced significantly less fruit on a per-tree basis, which is an expected outcome given their significantly smaller canopy size. However, when evaluating Yield Efficiency (kg fruit per m\u0026sup3; of canopy), this metric revealed a contrasting pattern. 'Arbequina' and 'Arbosana' demonstrated superior efficiency, producing significantly more fruit per unit of vegetative structure (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eB). The high efficiency of these cultivars means they deliver a higher return on investments in water, nutrients, and land area dedicated to canopy growth. 'Coratina' and 'Maraqi' exhibited statistically similar but significantly lower yield efficiency. For 'Coratina', this confirms that a substantial portion of its resources is allocated to maintaining its large vegetative framework rather than being directed toward fruit production. The low efficiency of 'Maraqi' suggests that its balanced growth strategy, while stable, does not translate into high reproductive efficiency under these conditions. For orchardists in newly reclaimed areas, this trade-off is central to cultivar selection. Choosing 'Coratina' prioritizes ultimate per-tree production but requires more space and resources per unit of yield. Choosing 'Arbequina' or 'Arbosana' prioritizes maximizing output per land area, water volume, and input investment, which is typically the goal of modern olive cultivation.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"4. Physical fruit characteristics","content":"\u003cdiv id=\"Sec20\" class=\"Section2\"\u003e \u003ch2\u003e4.1. Fruit size and weight\u003c/h2\u003e \u003cp\u003eA consistent and significant hierarchy was observed for fruit weight and fruit volume across both seasons. 'Coratina' consistently produced the largest and heaviest fruits, and significantly outperforming the other cultivars (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eA). The Italian origin of 'Coratina' has selected for larger fruit size compared to Spanish cultivars. 'Arbequina' consistently produced fruits that were significantly larger and heavier than those of 'Arbosana' and 'Maraqi'. This finding is crucial for orchard management, as fruit size can influence harvesting efficiency and processing parameters. The larger fruit volume of 'Arbequina' may also make it marginally more suitable for table olive production in addition to oil extraction (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eB). The stability of this ranking across seasons underscores the strong genetic control over this trait.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec21\" class=\"Section2\"\u003e \u003ch2\u003e4.3. Oil Content %\u003c/h2\u003e \u003cp\u003eThe Oil Content (% dry weight) is the ultimate qualitative parameter for oil-dedicated cultivars. 'Coratina' demonstrated a clear superiority, achieving significantly higher oil content than all other cultivars in both seasons (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). This high oil concentration, combined with its large fruit size and high absolute yield, makes 'Coratina' an outstanding cultivar for oil production in terms of quantitative output. 'Arbequina' and 'Maraqi' registered statistically similar oil contents, forming a middle group. While lower than 'Coratina', their oil content is still commercially viable and aligns with standard expectations for these cultivars. The data suggests that 'Arbosana' may have slightly higher oil potential than 'Arbequina' and 'Maraqi', particularly in the second season where it grouped with 'Coratina', though more data would be needed to confirm this trend. This potential for high oil yield in a compact tree is a key reason for 'Arbosana's' popularity in high-density systems. In conclusion, the comparative analysis of fruit morphology and oil content confirms that there is no single \"best\" cultivar. The optimal choice is a function of the specific orchard management system, resource availability, and commercial objectives, ranging from the high output 'Coratina' to the highly efficient 'Arbequina' and 'Arbosana'.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis superior vegetative expansion suggests that 'Coratina' possesses a genetic constitution that allows for more efficient resource capture and biomass accumulation under the moderate salinity and low fertility of the experimental soil. This aligns with its known reputation as a vigorous and resilient cultivar in Mediterranean environments[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. This is characteristic of their genetic predisposition for lower vigor, which is a key trait selected for high-density planting systems to reduce inter-tree competition[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. The lower vigor cultivars, 'Arbequina' and 'Arbosana', exhibited shorter annual shoot elongation and smaller leaf sizes. This reduced vegetative effort can be interpreted as a conservative strategy, allocating resources away from excessive growth and potentially towards other functions like maintenance or reproduction under stress conditions[\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. The intermediate values for 'Maraqi' further confirm its middle position in terms of vegetative growth potential in this challenging environment. The consistent growth patterns across both seasons, with 'Coratina' \u0026gt; 'Maraqi' \u0026gt; 'Arbequina'/'Arbosana', highlight the strong genotypic control over vegetative growth traits. However, the observed numerical increase in all growth parameters from the first to the second season for each cultivar suggests a positive response to improved root establishment and perhaps more favorable climatic conditions in the second year, a common phenomenon in young orchards[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThis suggests a high investment in the photosynthetic apparatus, which is consistent with its observed supports its high superior vegetative growth and likely carbohydrate demand for both growth and fruit production[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. A lower chlorophyll content can be interpreted as a conservative or protective strategy under stress. It may reduce light absorption capacity, thereby minimizing the production of reactive oxygen species (ROS) when the photosynthetic machinery is compromised by drought or salinity, a common stress-response mechanism[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. This indicates highly effective stomatal regulation and possibly superior osmotic adjustment, allowing these cultivars to avoid dehydration and maintain physiological function under soil water deficit[\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. The accumulation of the amino acid Proline is a well-established biochemical response to osmotic stress (salinity or drought) and serves as a reliable biomarker for the severity of abiotic stress perception within the plant[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. Their effective stress-avoidance mechanisms such as stomatal control apparently prevented the severe cellular dehydration that triggers major osmolyte synthesis. This suggests they were successful in minimizing physiological disruption, thereby reducing the metabolic cost of stress acclimation. 'Arbosana' showed an intermediate proline accumulation, reflecting a moderate level of perceived stress[\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. This prolific flowering is a known characteristic of this cultivar and represents a high-investment strategy to ensure reproductive success by saturating the environment with potential fruit sites[\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. The significantly higher Gynosterility (flower abortion) rate in 'Coratina' indicates that a substantial portion of its prolific flower production was defective and incapable of setting fruit. This phenomenon is well-documented in some high-flowering-intensity olive cultivars and is often exacerbated by abiotic stresses, which can disrupt floral organ development[\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. This aligns with the concept of a \"flowering-fruit set trade-off\" observed in many fruit tree species[\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThis metric is critical for assessing the economic and environmental resource use efficiency of an orchard system[\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. ). This is a well-known characteristic of this cultivar, which is valued for its high pulp-to-pit ratio and oil yield[\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eThe amount of oil that is present in the fruits, the oil content at harvest, is the defining feature of the quality and economic viability of olive oil cultivars. Our analytical research indicates that the genotype of olive oil cultivars shows considerable and reliable variation for oil content under the combined influence of soil quality and water availability in newly developed soils. The results clearly demonstrate that 'Coratina' has a greater concentration of oils by weight (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e), strongly supporting its long held view of being among the best oil-producing cultivars[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. As such, because of the genetically determined high-oil characteristics of 'Coratina' and its demonstrated fruit size advantages and increased oil production per tree, this cultivar is an exceptional candidate to enhance the total production of gross oil with respect to area planted, provided that space or resources do not limit the number of trees that can be established. This is consistent with the historical use of 'Coratina' in large, extensive plantings in Southern Italy, where the robust growth and high oil production of the cultivar have been cultivated.\u003c/p\u003e \u003cp\u003eOil concentrations measured for \u0026lsquo;Arbequin\u0026rsquo; and \u0026lsquo;Maraqi\u0026rsquo; are both intermediate in statistical terms, but within the bounds of what is commercially viable for both cultivars. Therefore, we can consider them both reliable for producing oil under marginal growing conditions. However, 'Arbosana' must be evaluated more thoroughly. \u0026lsquo;Arbosana\u0026rsquo; has been grouped with \u0026lsquo;Arbequina\u0026rsquo; and \u0026lsquo;Maraqi', but exhibits a tendency to cluster with \u0026lsquo;Coratina\u0026rsquo; in two seasons, indicating potential for higher oil content. This indicates an agronomic opportunity to identify a cultivar capable of producing large amounts of oil from a small tree with weak vigor across multiple sites and seasons. This is one of the primary driving forces behind the global adoption of \u0026lsquo;Arbosana\u0026rsquo; for olive production in high-density (\u0026lsquo;super high-density\u0026rsquo;) production systems, where maximum yield efficiency of canopies and land area, rather than tree-by-tree productivity, are the priorities of production[\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]. Thus, when data related to productive capacity, resource-use efficiency, and plant physiology, we draw one conclusion that unites these concepts: no one cultivar is superior; rather there is a distinct trade-off between resource-use efficiency and productive capacity as determined by the physiological strategies of each cultivar. Choosing the best cultivar is not just about picking the one that has the greatest oil levels; there is a strategic aspect in looking at how the selected cultivar will integrate to the other management goals and resources of the orchard.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis study highlights the contrasting adaptive strategies and agronomic performance of four olive cultivars, Coratina\u0026rsquo;, \u0026lsquo;Arbequina\u0026rsquo;, \u0026lsquo;Arbosana\u0026rsquo;, and \u0026lsquo;Maraqi\u0026rsquo; under newly reclaimed soils. Results reveal a trade-off between vegetative growth, stress response, and yield efficiency, underscoring the need for context-specific cultivar selection. \u0026lsquo;Coratina\u0026rsquo; showed vigorous growth, high yield, and superior oil content, but at the cost of severe physiological stress, making it productive yet risk-prone. In contrast, Arbequina\u0026rsquo; and \u0026lsquo;Arbosana\u0026rsquo; adopted a resource-efficient strategy, combining compact growth with high yield efficiency and stable water status, suiting them to high-density, intensive systems. \u0026lsquo;Maraqi\u0026rsquo; offered resilience through superior water retention and minimal stress indicators, making it best suited for drought-prone or uncertain environments. No cultivar is universally superior. Choice depends on production goals and resource availability: Coratina\u0026rsquo; for maximum yield and oil, \u0026lsquo;Arbequina\u0026rsquo;/\u0026lsquo;Arbosana\u0026rsquo; for efficiency-driven systems, and \u0026lsquo;Maraqi\u0026rsquo; for stability under water-limited conditions. These findings provide a framework for sustainable olive expansion in marginal lands, with future studies needed on long-term performance under water stress.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors confirmed that the institutional committee and licensing committee approved the experiments, including all relevant details and that all experiments have been performed in accordance with \u0026nbsp;specified named guidelines and regulations.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u0026nbsp;\u003c/strong\u003eThe article contains no such material that may be unlawful, defamatory, or which would, if published, in any way whatsoever, violate the terms and conditions as laid down in the agreement.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and material:\u0026nbsp;\u003c/strong\u003eThe data generated and/or analysed during the current study are available per request to the corresponding author.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no conflict of interest in the publication.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e This research did not receive any external funding.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors' contributions:\u003c/strong\u003e Conceptualization HFA and AEH; Data curation HFA, and ANA; Formal analysis HFA, AEH, IAE, and ANA; Investigation AEH, and ANA; Methodology HFA and ANA; Project administration AMA; Resources IAE, and ANA; Software HFA, and ANA; Supervision AEH; Validation AEH, and ANA; Visualization HFA, AEH, IAE, and ANA; Writing - original draft AEH; Writing - review and editing AEH. All authors read and approved the final manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eFraga, H., Moriondo, M., Leolini, L. \u0026amp; Santos, J. A. Mediterranean olive orchards under climate change: A review of future impacts and adaptation strategies. \u003cem\u003eAgronomy\u003c/em\u003e \u003cstrong\u003e11\u003c/strong\u003e, 56 (2020).\u003c/li\u003e\n \u003cli\u003eKavvadias, V. \u0026amp; Koubouris, G. Sustainable soil management practices in olive groves. in \u003cem\u003eSoil fertility management for sustainable development\u003c/em\u003e 167\u0026ndash;188 (Springer, 2019).\u003c/li\u003e\n \u003cli\u003eBrito, C., Dinis, L.-T., Moutinho-Pereira, J. \u0026amp; Correia, C. M. Drought stress effects and olive tree acclimation under a changing climate. \u003cem\u003ePlants\u003c/em\u003e \u003cstrong\u003e8\u003c/strong\u003e, 232 (2019).\u003c/li\u003e\n \u003cli\u003eLo Bianco, R., Proietti, P., Regni, L. \u0026amp; Caruso, T. Planting systems for modern olive growing: Strengths and weaknesses. \u003cem\u003eAgriculture\u003c/em\u003e \u003cstrong\u003e11\u003c/strong\u003e, 494 (2021).\u003c/li\u003e\n \u003cli\u003eGuermazi, E., Wali, A. \u0026amp; Ksibi, M. Combining remote sensing, SPAD readings, and laboratory analysis for monitoring olive groves and olive oil quality. \u003cem\u003ePrecision Agriculture\u003c/em\u003e \u003cstrong\u003e25\u003c/strong\u003e, 65\u0026ndash;82 (2024).\u003c/li\u003e\n \u003cli\u003eKarimi, S., Rahemi, M., Rostami, A. A. \u0026amp; Sedaghat, S. Drought effects on growth, water content and osmoprotectants in four olive cultivars with different drought tolerance. \u003cem\u003eInternational Journal of Fruit Science\u003c/em\u003e \u003cstrong\u003e18\u003c/strong\u003e, 254\u0026ndash;267 (2018).\u003c/li\u003e\n \u003cli\u003eSpormann, S. \u003cem\u003eet al.\u003c/em\u003e Accumulation of proline in plants under contaminated soils\u0026mdash;are we on the same page? \u003cem\u003eAntioxidants\u003c/em\u003e \u003cstrong\u003e12\u003c/strong\u003e, 666 (2023).\u003c/li\u003e\n \u003cli\u003eGucci, R. \u003cem\u003eet al.\u003c/em\u003e Fruit growth, yield and oil quality changes induced by deficit irrigation at different stages of olive fruit development. \u003cem\u003eAgricultural Water Management\u003c/em\u003e \u003cstrong\u003e212\u003c/strong\u003e, 88\u0026ndash;98 (2019).\u003c/li\u003e\n \u003cli\u003eCamposeo, S., Vivaldi, G. A., Montemurro, C., Fanelli, V. \u0026amp; Cunill Canal, M. Lecciana, a new low-vigour olive cultivar suitable for super high density orchards and for nutraceutical EVOO production. \u003cem\u003eAgronomy\u003c/em\u003e \u003cstrong\u003e11\u003c/strong\u003e, 2154 (2021).\u003c/li\u003e\n \u003cli\u003eMolinu, M. G. \u003cem\u003eet al.\u003c/em\u003e Looking for Typical Traits in Monovarietal VOOs According to Their Phenolic Composition. \u003cem\u003eFoods\u003c/em\u003e \u003cstrong\u003e13\u003c/strong\u003e, 3425 (2024).\u003c/li\u003e\n \u003cli\u003eELSORADY, M. E., MOHAMED, A. S. \u0026amp; MOHAMED, E. S. Influence of organic fertilization and irrigation on quality of maraqi cultivar virgin olive oil. \u003cem\u003eEgyptian Journal of Agricultural Research\u003c/em\u003e \u003cstrong\u003e92\u003c/strong\u003e, 709\u0026ndash;728 (2014).\u003c/li\u003e\n \u003cli\u003ePeel, M. C., Finlayson, B. L. \u0026amp; McMahon, T. A. Updated world map of the K\u0026ouml;ppen-Geiger climate classification. \u003cem\u003eHydrology and earth system sciences\u003c/em\u003e \u003cstrong\u003e11\u003c/strong\u003e, 1633\u0026ndash;1644 (2007).\u003c/li\u003e\n \u003cli\u003eFern\u0026aacute;ndez-Escobar, R. Olive nutritional status and tolerance to biotic and abiotic stresses. \u003cem\u003eFrontiers in plant science\u003c/em\u003e \u003cstrong\u003e10\u003c/strong\u003e, 1151 (2019).\u003c/li\u003e\n \u003cli\u003eRosati, A., Wolz, K. J., Murphy, L., Ponti, L. \u0026amp; Jose, S. Modeling light below tree canopies overestimates net photosynthesis and radiation use efficiency in understory crops by averaging light in space and time. \u003cem\u003eAgricultural and Forest Meteorology\u003c/em\u003e \u003cstrong\u003e284\u003c/strong\u003e, 107892 (2020).\u003c/li\u003e\n \u003cli\u003eKř\u0026iacute;žov\u0026aacute;, K. \u003cem\u003eet al.\u003c/em\u003e Using a single-board computer as a low-cost instrument for SPAD value estimation through colour images and chlorophyll-related spectral indices. \u003cem\u003eEcological Informatics\u003c/em\u003e \u003cstrong\u003e67\u003c/strong\u003e, 101496 (2022).\u003c/li\u003e\n \u003cli\u003eSlama, A., Mallek-Maalej, E., Ben Mohamed, H., Rhim, T. \u0026amp; Radhouane, L. A return to the genetic heritage of durum wheat to cope with drought heightened by climate change. \u003cem\u003ePLoS One\u003c/em\u003e \u003cstrong\u003e13\u003c/strong\u003e, e0196873 (2018).\u003c/li\u003e\n \u003cli\u003eBates, L. S., Waldren, R. P. A. \u0026amp; Teare, I. D. Rapid determination of free proline for water-stress studies. \u003cem\u003ePlant and soil\u003c/em\u003e \u003cstrong\u003e39\u003c/strong\u003e, 205\u0026ndash;207 (1973).\u003c/li\u003e\n \u003cli\u003eSeifi, E., Guerin, J., Kaiser, B. \u0026amp; Sedgley, M. Flowering and fruit set in olive: a review. \u003cem\u003eIran. J. Plant Physiol\u003c/em\u003e \u003cstrong\u003e5\u003c/strong\u003e, 1263\u0026ndash;1272 (2015).\u003c/li\u003e\n \u003cli\u003eMontemurro, C., Dambruoso, G., Bottalico, G. \u0026amp; Sabetta, W. Self-incompatibility assessment of some Italian olive genotypes (Olea europaea L.) and cross-derived seedling selection by SSR markers on seed endosperms. \u003cem\u003eFrontiers in plant science\u003c/em\u003e \u003cstrong\u003e10\u003c/strong\u003e, 451 (2019).\u003c/li\u003e\n \u003cli\u003eFamiani, F. \u003cem\u003eet al.\u003c/em\u003e Deflowering as a Tool to Accelerate Growth of Young Trees in Both Intensive and Super-High-Density Olive Orchards. \u003cem\u003eAgronomy\u003c/em\u003e \u003cstrong\u003e12\u003c/strong\u003e, 2319 (2022).\u003c/li\u003e\n \u003cli\u003eFeldsine, P., Abeyta, C. \u0026amp; Andrews, W. H. AOAC INTERNATIONAL Methods Committee Guidelines for Validation of Qualitative and Quantitative Food Microbiological Official Methods of Analysis. \u003cem\u003eJournal of AOAC INTERNATIONAL\u003c/em\u003e \u003cstrong\u003e85\u003c/strong\u003e, 1187\u0026ndash;1200 (2002).\u003c/li\u003e\n \u003cli\u003eFamiani, F. \u003cem\u003eet al.\u003c/em\u003e Harvesting system and fruit storage affect basic quality parameters and phenolic and volatile compounds of oils from intensive and super-intensive olive orchards. \u003cem\u003eScientia Horticulturae\u003c/em\u003e \u003cstrong\u003e263\u003c/strong\u003e, 109045 (2020).\u003c/li\u003e\n \u003cli\u003eClodoveo, M. L. \u003cem\u003eet al.\u003c/em\u003e Research and Innovative Approaches to Obtain Virgin Olive Oils with a Higher Level of Bioactive Constituents. in \u003cem\u003eOlive and Olive Oil Bioactive Constituents\u003c/em\u003e 179\u0026ndash;215 (Elsevier, 2015). doi:10.1016/B978-1-63067-041-2.50013-6.\u003c/li\u003e\n \u003cli\u003eMaris, S. C., Teira-Esmatges, M. R., Arbon\u0026eacute;s, A. \u0026amp; Rufat, J. Effect of irrigation, nitrogen application, and a nitrification inhibitor on nitrous oxide, carbon dioxide and methane emissions from an olive (Olea europaea L.) orchard. \u003cem\u003eScience of The Total Environment\u003c/em\u003e \u003cstrong\u003e538\u003c/strong\u003e, 966\u0026ndash;978 (2015).\u003c/li\u003e\n \u003cli\u003eSobreiro, J., Patanita, M. I., Patanita, M. \u0026amp; Tomaz, A. Sustainability of High-Density Olive Orchards: Hints for Irrigation Management and Agroecological Approaches. \u003cem\u003eWater\u003c/em\u003e \u003cstrong\u003e15\u003c/strong\u003e, 2486 (2023).\u003c/li\u003e\n \u003cli\u003eRosati, A., Lodolini, E. M. \u0026amp; Famiani, F. From flower to fruit: fruit growth and development in olive (Olea europaea L.)\u0026mdash;a review. \u003cem\u003eFront. Plant Sci.\u003c/em\u003e \u003cstrong\u003e14\u003c/strong\u003e, 1276178 (2023).\u003c/li\u003e\n \u003cli\u003eEl Yamani, M. \u0026amp; Cordovilla, M. D. P. Tolerance Mechanisms of Olive Tree (Olea europaea) under Saline Conditions. \u003cem\u003ePlants\u003c/em\u003e \u003cstrong\u003e13\u003c/strong\u003e, 2094 (2024).\u003c/li\u003e\n \u003cli\u003eBen Abdallah, M. \u003cem\u003eet al.\u003c/em\u003e Unraveling physiological, biochemical and molecular mechanisms involved in olive (Olea europaea L. cv. Ch\u0026eacute;toui) tolerance to drought and salt stresses. \u003cem\u003eJournal of Plant Physiology\u003c/em\u003e \u003cstrong\u003e220\u003c/strong\u003e, 83\u0026ndash;95 (2018).\u003c/li\u003e\n \u003cli\u003eBen Abdallah, M., Methenni, K., Taamalli, W. \u0026amp; Ben Youssef, N. Post-stress recovery from drought and salinity in olive plants is an active process associated to physiological and metabolic changes. \u003cem\u003eActa Physiol Plant\u003c/em\u003e \u003cstrong\u003e46\u003c/strong\u003e, 120 (2024).\u003c/li\u003e\n \u003cli\u003ePoury, N., Seifi, E. \u0026amp; Alizadeh, M. Effects of Salinity and Proline On Growth and Physiological Characteristics of Three Olive Cultivars. \u003cem\u003eGesunde Pflanzen\u003c/em\u003e \u003cstrong\u003e75\u003c/strong\u003e, 1169\u0026ndash;1180 (2023).\u003c/li\u003e\n \u003cli\u003eCamarero, M. C. \u003cem\u003eet al.\u003c/em\u003e Characterization of Transcriptome Dynamics during Early Fruit Development in Olive (Olea europaea L.). \u003cem\u003eIJMS\u003c/em\u003e \u003cstrong\u003e24\u003c/strong\u003e, 961 (2023).\u003c/li\u003e\n \u003cli\u003eSilva, E. \u003cem\u003eet al.\u003c/em\u003e Olive Yield and Physicochemical Properties of Olives and Oil in Response to Nutrient Application under Rainfed Conditions. \u003cem\u003eMolecules\u003c/em\u003e \u003cstrong\u003e28\u003c/strong\u003e, 831 (2023).\u003c/li\u003e\n \u003cli\u003eGarnier, E. \u003cem\u003eet al.\u003c/em\u003e Leaf longevity and structure, fruit mass and phenology in 52 cultivated varieties and wild accessions of olive. \u003cem\u003eFunctional Ecology\u003c/em\u003e 1365-2435.70012 (2025) doi:10.1111/1365-2435.70012.\u003c/li\u003e\n \u003cli\u003eTrentacoste, E. R. \u003cem\u003eet al.\u003c/em\u003e Effect of regulated deficit irrigation during the vegetative growth period on shoot elongation and oil yield components in olive hedgerows (cv. Arbosana) pruned annually on alternate sides in San Juan, Argentina. \u003cem\u003eIrrig Sci\u003c/em\u003e \u003cstrong\u003e37\u003c/strong\u003e, 533\u0026ndash;546 (2019).\u003c/li\u003e\n \u003cli\u003eCecchi, L. \u003cem\u003eet al.\u003c/em\u003e Virgin Olive Oil By-Product Valorization: An Insight into the Phenolic Composition of Olive Seed Extracts from Three Cultivars as Sources of Bioactive Molecules. \u003cem\u003eMolecules\u003c/em\u003e \u003cstrong\u003e28\u003c/strong\u003e, 2776 (2023).\u003c/li\u003e\n \u003cli\u003eTous, J. The influence of growing region and cultivar on olives and olive oil characteristics and on their functional constituents. in \u003cem\u003eOlives and Olive Oil as Functional Foods\u003c/em\u003e (eds Shahidi, F. \u0026amp; Kiritsakis, A.) 45\u0026ndash;80 (Wiley, 2017). doi:10.1002/9781119135340.ch4.\u003cem\u003e\u003c/em\u003e\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Olea europaea L., cultivar selection, proline, water relations, yield efficiency","lastPublishedDoi":"10.21203/rs.3.rs-8662502/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8662502/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eExpanding olive cultivation into marginal, newly reclaimed soils is vital for meeting global demand but poses significant challenges due to abiotic stresses. Success in these conditions depends heavily on cultivar selection, but there is a dearth of comparative information on contemporary cultivars in these settings. To evaluate the performance of four olive cultivars Arbosana, Arbequina, Coratina, and Maraqi in a recently reclaimed sandy soil, this study carried out an extensive two-year field experiment. A range of physiological (chlorophyll content, relative water content (RWC), leaf proline concentration, reproductive (inflorescence traits, fruit set, yield), vegetative growth, and fruit physical properties, oil content parameters were evaluated. The findings showed that adaptive strategies varied significantly by genotype. With the highest absolute fruit yield, the most vigorous vegetative growth, and the highest oil content, \"Coratina\" demonstrated a high-productivity but high-stress strategy. However, this was accompanied by the highest proline accumulation and the lowest RWC, suggesting extreme physiological stress. However, \"Arbequina\" and \"Arbosana\" showed a cautious, effective approach, maintaining a high RWC with little proline accumulation and achieving superior yield efficiency (kg fruit/m\u0026sup3; canopy), which is a sign of successful stress avoidance. With intermediate growth and yield, the highest RWC, and the lowest proline levels, \"Maraqi\" showed a balanced, stress-avoidant profile that suggested strong innate resilience. The results show a basic trade-off between resource use efficiency and productivity. In conclusion the best cultivar selection depends on management objectives and resource availability: \"Coratina\" for maximizing yield in situations where resources are not limited, \"Arbequina\" and \"Arbosana\" for high density, resource efficient intensive systems, and \"Maraqi\" as a robust option for sustainable cultivation in unpredictable water regimes.\u003c/p\u003e","manuscriptTitle":"A Comparative Study of the Growth, Yield, and Physiological Responses of Arbosana, Arbequina, Coratina, and Maraqi Olive Cultivars","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-29 15:57:19","doi":"10.21203/rs.3.rs-8662502/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-02-24T04:31:23+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-23T15:07:01+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-11T16:22:38+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-10T16:57:25+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-10T12:45:03+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"22556355525329735273482648205024367","date":"2026-02-02T07:17:30+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"60396179662593145471193861189549731378","date":"2026-02-01T13:02:06+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"216602906623397737390401669665756093701","date":"2026-01-29T13:55:08+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"144605924864265745778260618138229890798","date":"2026-01-29T11:01:31+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"74463005994774609512015758610765055119","date":"2026-01-29T09:03:36+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"94825214376347076497359719047028998091","date":"2026-01-27T17:25:55+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"197857243811584831930039043866096790091","date":"2026-01-27T10:58:46+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-01-27T10:32:04+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-01-27T10:30:23+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-01-27T10:02:54+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-01-22T08:39:22+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2026-01-22T08:04:48+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"373beae1-f20a-429c-950b-161379ac215f","owner":[],"postedDate":"January 29th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":61896761,"name":"Biological sciences/Ecology"},{"id":61896762,"name":"Earth and environmental sciences/Ecology"},{"id":61896763,"name":"Biological sciences/Physiology"},{"id":61896764,"name":"Biological sciences/Plant sciences"}],"tags":[],"updatedAt":"2026-05-04T11:23:20+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-29 15:57:19","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8662502","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8662502","identity":"rs-8662502","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}