Olive Yield Research Articles

Identifying superior drought-tolerant olive genotypes and their biochemical and some physiological responses to various irrigation levels

Drought is currently one of the most severe abiotic factors limiting agricultural production. The high rates of population growth and global warming are expected to further exacerbate the threat of drought, especially in areas with a semi-arid climate as in the Middle East region. Selecting genotypes for improved drought tolerance has long been of interest for those involved in horticulture. The present research investigated the reaction of seven 10-year-old olive genotypes to drought stress in Dallaho Olive Research Station, Iran. To determine the reaction of genotypes to drought stress, physiological and biochemical characteristics, fruit and oil yield, and water use efficiency were measured. The results showed that different genotypes react differently to drought stress while drought decreased vegetative and reproductive traits such as shoot length and diameter, relative water content of the leaves, Ca and K percentage, and fruit yield. Finally, Dd1 and Bn6 showed the highest oil and fruit yield per hectare and the highest water use efficiency. In addition, Bn3 had a favorable status in most of the measured parameters. So, they can be suggested as the genotypes that are tolerant of drought stress. The results also showed that olive yield and irrigation management can be improved by applying proper irrigation levels and using tolerant genotypes.

Climate change projections for olive yields in the Mediterranean Basin

AbstractThe olive tree is one of the most important crops in the Mediterranean basin. Given the strong climatic influence on olive trees, it becomes imperative to assess climate change impacts on this crop. Herein, these impacts were innovatively assessed, based on an ensemble of state‐of‐the‐art climate models, future scenarios and dynamic crop models. The recent‐past (1989–2005) and future (2041–2070, RCP4.5 and RCP8.5) olive growing season length (GSL), yield, growing season temperature (GST) and precipitation (GSP), potential (ETP) and actual (ETA) evapotranspiration, water demand (WD) and water productivity (WP) were assessed over Southern Europe. Crop models were fed with an ensemble of EURO‐CORDEX regional climate model data, along with soil and terrain data. For the recent‐past, important differences between western and eastern olive growing areas are found. GSL presents a strong latitudinal gradient, with higher/lower values at lower/higher latitudes. Yields are lower in inner south Iberia and higher in Italy and Greece, which is corroborated by historical data. Southern Iberia shows higher GST and lower GSP, which contributes to a higher ETP, lower ETA and, consequently, stronger WD. Regarding WP, the recent‐past values show similar ranges across Europe. Future projections point to a general increase in GSL along with an increase in GST up to 3°C. GSP is projected to decrease in Western Europe, leading to enhanced WD and consequently a yield decrease (down to −45%). Over eastern European, GSP is projected to slightly increase, leading to lower WD and to a small yield increase (up to +15%). WP will remain mostly unchanged. We conclude that climate change may negatively impact the viability of olive orchards in southern Iberia and some parts of Italy. Thus, adequate and timely planning of suitable adaptation measures are needed to ensure the sustainability of the olive sector.

The effect of nitrogen fertilization on the incidence of olive fruit fly, olive leaf spot and olive anthracnose in two olive cultivars grown in rainfed conditions

Pests and diseases can cause significant loss of olive yield and/or justify control measures with pesticides which are harmful to the environment. Several agroecological variables, such as fertilization, can favour or limit the incidence of pests and diseases. However, in olive, few studies exist on the subject than can assist in the implementation of more sustainable phytosanitary measures. In this study the effect of nitrogen fertilization (0, 20, 40 and 120 kg N ha−1) on the incidence of olive fruit fly (Bactrocera oleae), olive leaf spot (Spilocaea oleaginea) and olive anthracnose (Colletotrichum gloeosporioides) was evaluated in two olive orchards of the cultivars ‘Cobrançosa’ and ‘Madural’. The study took place in 2017 and 2018 in Lombo, NE Portugal. Nitrogen fertilization significantly increased olive yield and nitrogen concentrations in plant tissues and induced a delay in fruit maturity. The incidence of the olive fruit fly was significantly lower in the more fertilized treatments of both cultivars. However, ‘Madural’ showed itself to be more susceptible than ‘Cobrançosa’ to olive fruit fly. The effect of nitrogen on the reduction of the incidence of the olive fruit fly was attributed to the delay caused in fruit maturation, which might have desynchronized the attractiveness of the fruits for insects to lay their eggs on their flight curve. In contrast, olive leaf spot and olive anthracnose were not influenced by nitrogen fertilization. As a result, nutrient management in olive groves must balance carefully the requirements of economic rationality with environmental preservation, particularly with regard to the harmful relationship between the use of excessive nitrogen rates and several adverse environmental effects.

THE ECONOMIC ANALYSIS OF PRODUCTION AND COST FUNCTIONS OF OLIVE CROP AT MATROUH GOVERNORATE

E ECONOMIC ANALYSIS OF PRODUCTION AND COST FUNCTIONS OF OLIVE CROP AT MATROUH GOVERNORATE The problem of research was the limitations of water resources with the growing water needs in agriculture. The research aimed at studying the estimation of the production and costs functions of the olive crop.Production functions show the extent to which agricultural production units achieve economic efficiency in their use of production resources involved in the production process and the extent to which these units maximize the profits of the agricultural product. The important indicators both at the level of the production unit and at the national level the relationship between costs and production, which can be used in the formulation and analysis of price policies and help agricultural producers in making their own productive decisions, which would encourage producers to continue or to expand the production process or stop production, as well as to determine the volume of production that maximizes profits and thus achieve economic efficiency of the use of productive elements. The Results showed that to determine the parameters of the yield function of the olive yield from the data of the research sample according to the estimated model in the form of cup-Douglas, by introducing all the productive elements affecting the total output of the olive yield, (EP) for the function by about 0.51 for the total sample and 0.99, 1.06 and 1.02 for the three categories respectively. This shows that the production is in the first stage and the optimum production volume which reduces the costs of olive production in the total sample of the study was about 4.3 tons and the other three categories Reached 1.98 tons, 2.3 tons, 3.4 tons, respectively , And that the total actual farm size of the total sample was about 2.5 tons, which is less than the optimal production volume and 2.2 tons, 2.3 tons, 3 tons, which is greater than the optimal production volume in the third category. As for the size of economic production, which maximizes profit, 4.9 tons in the total sample and in the other three categories reached 2 tons, 2.38 tons, 4.9 tons, respectively. The research recommends to develop rain harvesting methods, introduction of modern supplementary irrigation techniques to increase the increase production and the level of economic efficiency of olives on farms.efficiency of supplementary irrigation, awareness of the importance of tillage operations to increase soil permeability so that it can absorb the largest amount of rainwater and store it in layers under the surface of the soil to benefit trees during the growing season, and caring for the human element to

Soil and foliar applied boron in olive: tree crop growth and yield, and boron remobilization within plant tissues

Boron (B) has great importance in the fertilizer recommendation programs of olive, since B deficiency is a frequent nutritional disorder. This paper reports results of the olive response to applied B from two 3-year field trials (ExpF1, ExpF2) and two pot experiments (ExpP1, ExpP2). The ExpF1 was installed in a 3-year-old orchard and the ExpF2 consisted of planting young trees with the aboveground biomass yield being recorded. In ExpP1, B was applied to the soil or as a foliar spray to the whole of the canopy. The ExpP2 consisted of the application of B to selected parts of the canopy. The concentration of B in the existing tissues receiving the spray directly and in the new shoots developing after the B application was determined. The performance of the crop, including olive yield, did not increase in ExpF1 with soil-applied B. However, dry matter yield of young plants in ExpF2 significantly increased with B application. The application of B, both as a soil fertilizer and as a foliar spray, significantly increased the B concentration in all tissues and in all experiments. From ExpP1, soil applied B proved to be a more powerful tool of delivering high amounts of B to the plant than foliar spray. From ExpP2, B was shown to be mobile in the tree to some extent, although the mobility appears to be cultivar-dependent. In 'Arbequina' the older leaves that received the foliar spray showed higher B levels than the young leaves that developed thereafter, whereas in 'Cobrançosa' this difference was not observed.

Self-Incompatibility Assessment of Some Italian Olive Genotypes (Olea europaea L.) and Cross-Derived Seedling Selection by SSR Markers on Seed Endosperms.

The morphology of olive flowers allows either self- or cross-pollination that could partially explain the existence of both reproductive features in this species. However, a high degree of self-incompatibility is reported for many olive genotypes, that could be an important reproductive barrier influencing olive yield. Due to the strong environmental influence, results of compatibility tests are often contradictory, making cultivar classification quite imprecise. In this study, the self-incompatibility value has been determined for four olive genotypes (Bella di Spagna, Coratina, Leccino, and Ogliarola barese) widespread in the Mediterranean basin. Moreover, the incompatibility relationships of cultivar Coratina with some suitable pollinizers (Leccino, Oliastro, and Picholine) have been studied in controlled crosses: the in vitro germination potential of progenies has been evaluated and the selection of cross-derived embryos has been indirectly performed by the molecular characterization of the corresponding endosperm. The results increase knowledge on factors affecting self-compatibility in olive. Moreover, they provide useful information to farmers about the most effective cultivars for the set-up of new olive grove or for graft planning. Finally, they provide a new strategy and procedure based on endosperm analysis by SSRs for an accurate, fast, and relatively cheap screening of embryos/seedlings.

Natural habitat increases natural pest control in olive groves: economic implications

Natural habitat at the landscape scale can promote biological control of crop pests, but farmers often regard natural habitat as a cost or a lost economic opportunity. Evaluating the benefits of promoting natural habitats in economic terms should make different management alternatives easier to compare. However, it is important to understand the mechanisms underlying the connection between natural habitat and natural pest control. In this study, we link measurements of natural habitat and ground cover with abundances of multiple natural enemy groups and biological control of the olive pest Prays oleae to describe spatial patterns in biocontrol and the economic value associated. Natural habitat increased biocontrol and crop yields by an average of 186.36 €/ha. This could be attributable to the entire community of predatory natural enemies present in the olive regardless of natural habitat. One predator species of this community, Anthocoris nemoralis, whose abundance was influenced by natural habitat, was strongly associated with elevated biocontrol. We hypothesize that this predator species could be the link between natural habitat and the biological control. Our results suggest that olive growers could stand to gain from conserving natural habitat. Moreover, our evidence suggests that minimizing the use of chopped pruning remains may result in increased biocontrol by bolstering the abundance of A. nemoralis. More generally, our study indicates that diversifying olive orchards and surrounding landscapes may improve olive yields.

A new aerobiological indicator to optimize the prediction of the olive crop yield in intensive farming areas of southern Spain

In the present study, bio-meteorological regression models for forecasting the fruit produced by the olive trees in Jaen (southern Spain), the province with the largest extension of olive groves in the world, were revised and improved. The new forecasting models were constructed using partial least-squares regression, taking the annual olive yield as the dependent variable and several aerobiological and meteorological parameters as the independent variables. The models were validated following a full cross-validation method. A 23-year period (1994–2016) was used. The number of days with pollen concentrations ≥400 pollen grains m−3 was revealed as a newfangled predictive variable to accurately predict the olive harvest in this area, being included in the forecasting model with the highest determination coefficient value (R2 = 0.89). Weather-related variables such as the cumulative precipitation from October to December of the previous year or the mean maximum temperature from January to March were also factors of particular importance on crop production. The new model proposed provides early and effective olive crop forecasting by using independent variables which can be easily obtained towards the middle of June, also incorporating to the model the phenological variability associated with changes in the local weather. The approach shown in this study readily could be applied to any potential new situation and to be extensible to other similar olive growing areas across the Mediterranean region.

Preliminary Evaluation of Olive (Olea europaea L.) Cultivars under Hot and Arid Environment of Mexico

Currently in Mexico there are few studies on agronomic management in olive production. The objective of this experiment was to evaluate eleven olive cultivars for table and oil production (Arbequina, Koroneiki, Arbosana, Kalamata, Barnea, Pendolino, Empeltre, Manzanilla of Sevilla, Carboncella, Frantoio and Cassaliva) under hot and arid environment of Mexico. The experiment was carried out during two consecutive years in 2015 and 2016 at National Research Institute for Forestry, Agriculture and Livestock (INIFAP) in the Experimental Station of Caborca, Sonora, Mexico. The plantation was done on March, 2012 using a density of 100 trees ha-1 (10 x 10 m) under drip irrigation system. The parameters evaluated were vegetative parameters, yield, fruit quality and oil content. The experiment was analyzed using a randomized complete block design and five replications. The results showed statistical differences for all parameters evaluated. Arbequina obtained the highest olive yield with 34.5 and 70.3 kg per tree for the first and second year production, respectively and Barnea recorded the highest oil content with 19.2%. Finally, Manzanilla of Sevilla and Barnea varieties represent a good option as double-purpose varieties.

Impact of climate change on yield and water requirement of rainfed crops in the Setif region

PurposeThe purpose of this paper is to show the impact of climate change on yield and water requirement of three rainfed crops in Setif region.Design/methodology/approachThis study investigates likely changes in annual temperature and precipitation over Setif high plains region (North East of Algeria) among three future periods: 2025, 2050 and 2075. The projections are based on the SRES A2 and B2 scenarios. MAGICC-SCENGEN 5.3 v.2 was used as a tool for downscaling the four selected general circulation models (GCMs) output data. The expected impact of climate change on yield and water requirement of winter wheat, barley and olive was evaluated using the CROPWAT model.FindingsThe projection of the four GCMs showed that average temperature will increase by 0.73 to 3.42°C, and the precipitation will decrease by 1 to 52.7 percent, across the three future periods under the two SRES scenarios. Winter wheat and olive yields are expected to decrease under the three types of soils (heavy, medium and light). However, barley yield is expected to reduce under light soil only. Crop water requirements and irrigation water requirements are expected to increase under the two scenarios and across the three future periods.Originality/valueThis research is one of the first to study the impact of future climate change on water requirement and yield of rainfed crops over Setif region.

Effects of organic fertilizer application on yield, soil organic matter and porosity on kilis oil olive variety under arid conditions

Plant and soil must use fertilizer in order to maintain productivity in agricultural production. High-oil olive varieties are grown which has specific high economic value and locally in Kilis city under dry conditions. Kilis oil olive variety has produced without fertilization in dry conditions, in our city. It is necessary to fertilizer the soil and plant in order to ensure sustainability in agricultural production. If agricultural production made from non-fertilizer of plant and soil, soil physical conditions are degraded becomes poor and low yield is emerged. In this study, Kilis olive oil variety which is important variety in our country, they are 38years old and 25 kg/tree, 50 kg/tree and 75 kg/tree farm fertilizer was applied to them. As a result of the study, soil porosity values ranged from 36.2% and 55.8%. The highest porosity value was measured from 75kg/tree organic fertilizer application. Soil organic matter was determined to be 2.28% with soil organic matter while it was 0.95% with traditional application. The highest olive yield was obtained from 75kg/tree organic fertilizer application. Close results were obtained at 50 and 75 kg/tree fertilizer doses therefore 50kg fertilizer dose is recommended for olive producers.

The metabolic and genetic diversity of soil bacterial communities depends on the soil management system and C/N dynamics: The case of sustainable and conventional olive groves

Under Mediterranean type climates, a sustainable soil management aimed at increasing soil organic carbon and microbiological diversity is of key importance. The aim of this study was to characterize and compare soils from a mature Mediterranean olive (Olea europaea L.) orchard subjected to two different soil management systems (sustainable, Smng, and conventional, Cmng) for 18 years. Composite soil samples were analyzed qualitatively (pedological determinations) and quantitatively (soil C, N and pH). Bacterial metabolic activity and diversity were evaluated spectrophometrically by the Biolog® assay, while 16S-based metagenomics analysis was used to analyse the abundance of N-cycling bacteria. From the general analysis of the data obtained by the study of soil profiles and litter, C and N dynamics, and the genetic and functional diversity of soil bacteria, it emerged that the Smng system caused an improvement in soil organic matter in the topsoil layers, compared to the Cmng system, with consequent increases in the abundance of soil N-cycling bacteria but without affecting the indices related to total bacterial metabolic activity and diversity. The results obtained could promote the development of new approaches for optimizing soil carbon cycling, managing nutrient transport, and sustaining and improving olive yield and quality.

Olive Mill Wastewater Agronomic Valorization by its Spreading in Olive Grove

Olive mill wastewater (OMW) is one of the main waste streams of olive processing and its disposal can represent a relevant environmental issue in Mediterranean countries. OMW is characterised by high pollutant load, salinity and phytotoxic levels of polyphenols, but also by a high amount of organic compounds and plant mineral nutrients. This study aimed to investigate the OMW reuse as a whole effluent for its soil conditioner and fertilizer potentialities in agriculture, in the frame work of circular economy. For this purpose, OMW was applied at three doses (50, 100 and 200 m3 ha−1 year−1) over three successive years in olive field. Soil physico-chemical characteristics, enzymes activities and microbial properties, olive yield and olive oil quality were analysed. The findings revealed that the electrical conductivity, organic matter, total nitrogen, sodium, and potassium soil contents increased proportionally with OMW concentration and application frequency in the soil OMW-treated layers. Compared to their control soil counterparts, aerobic bacteria and fungi increased in proportion with the OMW spreading rates. Furthermore, all the soil enzyme activities tested (dehydrogenase, β-glucosidase and urease) were enhanced in the OMW-amended soils compared to the control. Vegetative activity and olive yield showed improvement according to the OMW level spread. With the only exception of the phenol content, which was significantly higher in the oils extracted from OMW treated olive trees than the control, the oil quality parameters did not show any significant difference. OMW agronomic application constitutes a suitable practice to better manage this effluent, with positive effects on olive production and oil quality. Consequently, OMW could be considered as a useful and low cost fertilizer in olive orchard requiring the use of suitable doses especially in the Mediterranean area where this practice has been extended.

Olive response to potassium applications under different water regimes and cultivars

Although potassium (K) is a macronutrient few studies have evaluated the response of olive tree to K fertilization. In this work results of two field and two pot K fertilizer experiments are presented. One of the field trials was conducted in a commercial young olive grove. The second was conducted in a plantation purposely established for this study. In the two field and the first pot experiment, the K supply was the single variation factor. The second pot experiment was arranged as a factorial with two K rates, two water regimes and two cultivars (‘Arbequina’ and ‘Cobrancosa’). K supply did not increase olive tree growth or yield. Accumulated olive yield in the first field experiment, for instance, varied from 2.46 and 2.84 kg tree−1, respectively in K treated and untreated plants. K supply increased the shoot/root ratio (1.6–2.0 from the control to the most fertilized treatment) and the concentration of K in roots (2.9–11.2 g kg−1) to a greater extent than in leaves (7.0–11.9 g kg−1), suggesting that shoots are a priority sink for K and roots may store the nutrient as a reserve. Plant water status and chlorophyll a fluorescence were not significantly affected by K applications. Plants suffering from water stress yielded less phytomass (40.2–56.4 g pot−1, respectively in control and well-watered plants) and showed higher K concentrations in leaves (14.2–11.6 g kg−1) and lower in roots (4.9–6.8 g kg−1) which is probably due to the reduction of K uptake from the dry soil. ‘Cobrancosa’ appeared to be more tolerant to water stress than ‘Arbequina’. These experiments showed a poor response of olive tree to K fertilization. Considering that K is usually applied by farmers every year, it seems that further studies on K fertilization in olive are needed in order to adjust K fertilizer rates to crop needs.

Olive tree response to the severity of pruning

Pruning has been seen as a means of improving olive tree productivity. The presumed importance of pruning was described by Columella (born 4 AD), and has persisted in general terms to the present. In this work, the effect of different pruning regimes was assessed from two field trials conducted in Mirandela, NE Portugal, in an olive grove of cv. 'Cobrançosa', rainfed managed. The first trial began after a light crop ("off" year) and received four pruning regimes (hard, moderate, light, and nonpruned control). The second trial started the following year, after a heavy crop ("on" year), and received two pruning regimes (hard and nonpruning). The study was carried out from 2012 to 2016. The accumulated crops of the four harvests performed after pruning in the first experiment did not significantly vary among nonpruning (8754 kg ha-1), slight pruning (8850 kg ha-1), and moderate pruning (8334 kg ha-1) but was significantly lower in hard pruning (6449 kg ha-1). The olive trees showed a high plasticity or tolerance to pruning, since olive yield did not decrease in response to light or moderate pruning regimes. It seems that it is possible to carry out light to moderate pruning to achieve several objectives of orchard management without significant loss of production. The results also showed that if pruning is done under a hard regime it should only be performed after a heavy crop. In addition, if done under a light regime, pruning can also reduce the alternate-year bearing behavior of the olive tree. Alternate bearing, Olea europaea, olive yield, pruning regime

Kaolin and salicylic acid foliar application modulate yield, quality and phytochemical composition of olive pulp and oil from rainfed trees

Abstract Olive orchards, rainfed managed, are threatened by the current and predicted adverse environmental conditions, which change the yield and quality of olive products, largely known for its benefits to human health. To mitigate these problems, it is highly recommended to perform some adjustments in agronomic practices, such as the use of foliar sprays that cloud help the trees to cope with climate change. During two consecutive years, olive trees were pre-harvest sprayed with kaolin (KL) and salicylic acid (SA) to attenuate the adverse effects of summer stress. Olive yield was increased by 97% and 72% with KL and SA, respectively. Phenolics and antioxidant capacity of both olives and olive oil increased and decreased in the first and second year, respectively, in a closely association with the prevailing climatic conditions. The foliar sprays did not significantly affect the oil quality indices, free acidity, peroxide value and K232 coefficient and decreased the K270 coefficient. This study strongly suggests that the applied products might be effective in mitigating the adverse environmental conditions, without substantial changes in fruit and olive oil quality.

Evaluation of four rejuvenation pruning methods on olive tree vegetative growth and yield

This study was conducted to evaluate the effect of four rejuvenation pruning methods on olive tree vegetative growth and yield. The study was conducted on a 45-year-old olive orchard of the cultivar 'Nabali Baladi' located in Al-Karak governorate, Jordan. The four pruning methods applied were coppicing of the whole tree at the ground level (T1), rejuvenation by removal of one main branch per year (T2), rejuvenation by crown shoots (T3) and rejuvenation from the underground section of the trunk base (T4). These treatments were compared with the control (traditional pruning). All treatments were applied in February 2008 and, after 3 years (2011, 2012 and 2013), the following measurements were taken: shoot diameter, shoot length, canopy diameter, fruit characters (fruit weight, width, number of fruits per kg) and yield per tree. The results showed that all treatments gave greater shoot diameter, shoot length and canopy diameter after rejuvenation pruning as compared with the control. Average fruit yield produced by all rejuvenated trees was significantly higher than that of the control trees (5.78 kg). The mean yield per tree amounted to 24.71, 22.77, 16.46 and 12.47 kg for treatments T2, T3, T1 and T4, respectively. All the fruit parameters measured including weight, length and width were significantly higher than those of the control.

Effect of rejuvenation pruning on the olive yield of different cultivars in a super-high-density olive orchard

Effect of rejuvenation pruning on the olive yield of different cultivars in a super-high-density olive orchard

Effect of soil and land factors on olive (Olea europaeaL.) yield and oil concentration in a rainfed Mediterranean system

Olive (Olea europaea L.) production in Mediterranean environments is mostly practiced under dryland and low-input conditions. The contribution of different soil and land parameters to olive yield is not well understood. The objective of this study was to evaluate the effect of different soil and land factors on olive nutritional status, yield, and oil concentration through surveying 'Zeiti' trees in northwestern Syria. To determine the most yield-affecting factors, correlations were established between yield, on the one hand, and soil/land factors as well as leaf nutrient concentrations, on the other hand. Soil fertility and land parameters (field slope, soil depth) and concentrations of leaf minerals were determined. Total available nutrients per tree were calculated using rootzone volume and nutrient concentrations. Yield correlated well with total available soil potassium (K, r2=0.68), total soil nitrogen (N) amount (r2=0.59), and soil depth (r2=0.56). A model that included soil K amount, soil depth, leaf boron (B), and leaf iron (Fe) concentrations explained 83% of the total yield variation. Oil concentration was weakly correlated to leaf zinc (Zn) (r2=0.37), B (r2=0.25), K (r2=0.20), and manganese (Mn) (r2=0.17) concentrations.

Effects of long-term olive mill wastewater spreading on the physiological and biochemical responses of adult Chemlali olive trees (Olea europaea L.)

Olive mill wastewater (OMW), a by-product from the olive oil extraction process, is annually produced in huge amounts in olive-growing areas and represents a significant environmental problem in Mediterranean areas. Whereas its high organic load and polyphenols concentrations are associated with troublesome environmental effects, its rich mineral and organic matter contents represent valuable nutrients. This study aimed to investigate adult ‘Chemlali’ olive trees subjected to OMW application at three doses (50, 100, and 200m3ha−1year−1) after eight successive years in an olive field. The main focus of the study was on gas exchange characteristics, photosynthetic pigments, soluble sugars, total phenolic compounds, antioxidant activity, leaf mineral nutrient and yield of the trees. The findings showed significant raises of net photosynthesis (Pn) and stomatal conductance (Gs) in OMW treated olive trees by 50 and 100m3ha−1. The lowest Pn and Gs rates were recorded in treatment with the highest OMW dose (200m3ha−1). In addition, olive trees amended with 200m3ha−1 exhibited a significant decrease of both chlorophyll (a+b) and carotenoid contents, while olive plants which received 50 and 100m3ha−1 of OMW showed higher photosynthetic pigments contents compared to the control olive trees. However, there was no significant difference in carotenoid content. Soluble sugars, total phenol contents and antioxidant activity increment were noticed in leaf plants amended with a 200m3ha−1 dose. The OMW spreading rates at 50 and 100m3ha−1 significantly increased the mineral contents of leaves (N, P, K, Ca and Mg). Nevertheless, the highest OMW application was associated with a significant reduction of olive leaf nutrient concentrations. Olive yield showed a continuous improvement of up to 100m3ha−1year−1 spread rate. The present study confirms that olive trees responses were dependent on OMW dose applied. Consequently, key physiological parameters of adult olive trees seemed to benefit from spreading OMW at moderate doses (50 and 100m3ha−1year−1) while the application of a higher dose (200m3ha−1year−1) seemed to disrupt them.