Olive Tree Plantations Research Articles

Morpho-molecular identification of the bark beetle Hylesinus macmahoni (Stebbing, 1909) (Coleoptera: Curculionidae: Scolytinae) infesting Olea europaea subsp. cuspidata (Wall. & G.Don) Cif., along with a brief biological synopsis

Abstract In Jammu and Kashmir's Govindpora (Ramban) and Salamabad (Baramulla), horticultural nurseries with a majority of Olea europaea subsp. cuspidata (Wall. & G.Don) Cif. plantings were examined for possible bark beetle attacks. These olive tree plantations are infested with a variety of insect pests, but the bark beetle Hylesinus macmahoni (Stebbing, 1909) did significant harm to the olive trees that carry fruit. The beetle attacks and consumes the phloem tissues of the plant during its development, causing the afflicted trees to become weak and eventually die. At both sites, infestations of H. macmahoni were discovered. The cytochrome oxidase subunit I (COI) gene was used to validate the species' diagnosis, and its morphological characteristics were re-described. The species has a polygynous matting system (one male and two females), producing two full and a third partial generation annually in Kashmir.

Agricultural Practices for Hillslope Erosion Mitigation: A Case Study in Morocco

In the last decades, the Rif area in Morocco has been frequently affected by soil erosion due to intense rainfall events. In order to help farmers improve their lives and avoid damages caused by this phenomenon, a management project (the MCA Project) aiming to grow fruit trees has been realized. The objective of this study was to evaluate, in three provinces of Morocco, the effect on the hydrological response of selected erosion control management techniques combined with olive tree plantations. The investigated variables were the final infiltration (If), the imbibition of rainwater (Pi), the runoff coefficient (Kr), and the soil detachment (D). In particular, for each investigated soil utilization, three replications of a rain simulation test (80 mm/h) and soil sampling were conducted. Results for surface conditions demonstrate that under vegetation in matorral and fallow, the surface is covered at more than 75% with a high content of organic matter (OM) at 4.5% and 2.6%, respectively. Despite the compaction observed in those land uses, the surface area opened exceeded 90% in the study area. Regarding the soils physical properties, they were rich in silt at more than 40%; the rate of porosity is high where bulk density is low. At the Taounate site, low porosity was at 62% in fallow and at 55% in plowing, with high densities of 1.01 g/cm2 and 1.2 g/cm2, respectively. Tests also demonstrate that vegetation has an important role in moisture conservation in the depths of 0 to 10 cm at all sites with macroagregate stability (MA%) compared to plowing sites. In terms of soil hydrology, vegetation reduces the runoff because, under matorral (it was at 0%), it avoids soil erosion.

Modeling Hydrological Responses to Land Use Change in Sejnane Watershed, Northern Tunisia

Land use change is a crucial driving factor in hydrological processes. Understanding its long-term dynamics is essential for sustainable water resources management. This study sought to quantify and analyze land use change between 1985 and 2021 and its impacts on the hydrology of the Sejnane watershed, northern Tunisia. Remote sensing and a SWAT model using the SUFI-2 algorithm to identify the most sensitive parameters were used to achieve this objective. Land use maps were developed for 1985, 2001 and 2021. For the last 37 years, the watershed experienced a slight decrease in forest, scrubland and forage crops, a significant reduction in grassland, and a conspicuous expansion of olive trees and vegetable crops. Given the scarcity of observed discharge data, a SWAT model was calibrated for the period 1997–2010 and validated for 2011–2019. Model performance was good for both calibration (NSE = 0.78, PBIAS = −6.6 and R2 = 0.85) and validation (NSE = 0.70, PBIAS = −29.2 and R2 = 0.81). Changes in land use strongly affected the water balance components. Surface runoff and percolation were the most influenced, showing an increase in runoff and a decrease in percolation by 15.5% and 13.8%, respectively. The results revealed that the construction of the Sejnane dam, the extension of irrigated perimeters and olive tree plantations were the major contributors to changes in hydrology.

What does the diet of the Common Starling (Sturnus vulgaris Linnaeus, 1758) in the Ziban Oasis (Algeria) indicate: pest or useful in agriculture?

The Common Starling (Sturnus vulgaris, L. 1758) is a migratory bird with a vast distribution throughout the Western Palearctic and beyond. It has gained notoriety as one of the most pernicious invaders globally due to its highly destructive nature. In Algeria, this species mostly affects olive tree plantations. We studied the diet of the Common Starling from October 2021 to February 2022 by dissecting the gizzards of 92 specimens from five localities in the Ziban region of Algeria. The investigation revealed a total of 708 prey items, consisting of animal and plant parts. The animal part was dominant, comprising 522 prey items that belonged to 42 species distributed among 27 families and 10 orders. Coleoptera were represented by 24 species in 14 families and were the most abundant order. The ant Messor barbarus and the beetle Opatrum sabulosum were the most consumed species. The plant part was represented by 9 species across 8 families and orders, with Phoenix dactylifera and Olea europea being the two most consumed species. Surprisingly, the European Starling menu also revealed 13 crop pests that were frequently present in its diet, such as the beetle Opatrum sabulosum, the fly Bactrocera oleae, and the moth Plodia interpunctella. The Shannon index (H’ = 4.27) showed that the diet of the Common Starling was diverse, and the value of evenness (E = 0.75) showed that the sampling was relatively even. We highlight that the Common Starling’s diet is very varied and changes based on the local food availability.

The Italian wall lizard, Podarcis siculus campestris, unexpected presence on Gorgona Island (Tuscan Archipelago)

We here report the unexpected presence of the Italian wall lizard (Podarcis siculus campestris) on Gorgona Island, in the Parco Nazionale Arcipelago Toscano (Tuscan Archipelago, Tyrrhenian Sea, Tuscany, Central Italy). Field observations were carried out in 2020 confirming its presence on the island, where it had never been reported before. We recorded 37 GPS points of the species in three major areas of Gorgona (with 50 lizard records) and about 180 visual counts regarding all age classes (newborns, juveniles and adults). The species was found in the urban area (site of state prison) and in two grassy and bushed areas, around and along olive tree plantations. Seven individuals were captured and their tails were used to assess the sequence variation of the mitochondrial CYB gene. Biometrical parameters were also evaluated for six of these individuals. We detected three distinct CYB haplotypes that were compared to Podarcis siculus CYB sequences available in public databases. They resulted identical or phylogenetically closest to those found in mainland Tuscany. One haplotype, found in three specimens, was identical to one previously detected at Orti Bottagone (WWF Oasis in Piombino), while the other two haplotypes were most similar to haplotypes reported in the Giannella peninsula and Pisa, respectively.

Southern Range Expansion of the Emerald Ash Borer, Agrilus planipennis, in Russia Threatens Ash and Olive Trees in the Middle East and Southern Europe

Agrilus planipennis (Coleoptera: Buprestidae) is the most serious invasive pest of ash trees (Fraxinus spp., Oleaceae) in the world. It has not yet reached the range of olive tree plantations, however it has been shown to complete its life cycle in this host tree. This pest native to East Asia was first found in Europe in Moscow in 2003 and has been spreading ever since. The aims of this study were to determine if the southern border of the range has already reached the Caucasus and to assess the potential range in this region based on host availability and heat availability. In 2021, we surveyed ash trees south to the known range in Russia. We did not find the pest in six cities in the North Caucasus region but found it in the city of Azov close to the Caucasus. Analysis of information about 550 localities of ash trees in the Caucasus showed that Fraxinus spp. is common throughout the region. The calculation of annual growing degree days base 10 °C indicated that the places where Fraxinus spp. grow above 1500 m are too cold for A. planipennis and therefore could potentially become a refuge for ash trees. The spread of A. planipennis to the Caucasus is of concern. First, the forest ecosystems of this region are endangered, since European ash Fraxinus excelsior is much more common there than in the currently infested regions in Russia. Second, the Russian Caucasus can become the gateway to Georgia, Armenia, Azerbaijan, Turkey and other countries of the Middle East and Southern Europe. We propose using Fraxinus angustifolia, F. ornus and Olea europaea growing in the Caucasus and adjacent regions as sentinel trees for the monitoring and pest risk assessment of these tree species.

Land suitability mapping for rainfed olive tree plantation in the West Bank, Palestine

Land suitability mapping for rainfed olive tree plantation in the West Bank, Palestine

Evolution and sustainability of the olive production systems in Southern Tunisia: Comparative study between traditional and modern farms in Zarzis region

The objective of this work is to carry out a comparative study between irrigated and rain-fed olive farms in arid area, Zarzis belonging to Southern Tunisia. In order to achieve this objective, a survey was carried out on nearly 30 farms: 13 are in the irrigated lands and 17 are in dry areas. As a first step, we proceeded through a socio-economic, technical and environmental assessment in order to determine the characteristics of each type of farms. As a second part, we tried to identify the strengths, weaknesses, opportunities and threats specific to the olive sector in this arid region, through SWOT method. The assessment shows that the irrigated farms were the object of modernization process, whose owners are really investors, aiming a rapid profitability by this farming activity. The farms are characterized by a high density of olive tree plantations and the stability of yields. Thus, they represent a source of employment in the region. On the other side, dry olive farms have a classic production system and low yields, generating not only a problem of profitability, but also of the viability of these farms, which explains the abandonment of these lands.

Weed cover controls soil and water losses in rainfed olive groves in Sierra de Enguera, eastern Iberian Peninsula

Soil erosion is a threat for the sustainability of agriculture and severely affects the Mediterranean crops. Olive groves are among the rainfed agriculture lands that exhibit soil and water losses due to the impact of unsustainable practices such as conventional tillage and herbicides abuse. To achieve a more sustainable olive oil production, alternative, greener crop management practices need to be tested in the field. Here, a weed cover (CW) treatment is tested at an olive tree plantation that has undergone conventional mechanical tillage for 20 years and results were compared against an adjacent control plantation that maintained tillage as a weed control strategy (CO). Both plantations were under the same tillage management for centuries and macroscopic analysis confirms they are otherwise comparable. Compared to the CO, where tilled soil cover was zero, 20 years of CW (weeds cover 64%; litter cover 5%) had led to significantly higher values of soil bulk density and soil organic matter. Results from rainfall simulation experiments at 55 mm h−1 on 0.25 m2 plots under CO (N = 25) and CW (N = 25) show that as a result of the improved soil structure, CW (i) reduced soil losses by two orders of magnitude (140 times), (ii) decreased runoff yield by one order of magnitude (from 2.65 till 27.6% of the rainfall), (iii) significantly reduced runoff sediment concentration (from 18.6 till 1.43 g l−1), and (iv) significantly delayed runoff generation (CO = 273 s; CW = 788 s). These results indicate that weed cover is a sustainable land management practice in Mediterranean olive groves and promotes sustainable agriculture production in mountainous areas under rainfed conditions, which are typically affected by high erosion rates such those found in the CO plots. Due to the spontaneous recovery of plant cover, we conclude that weed cover is an excellent nature-based solution to increase in the soil organic matter content and soil erosion reduction in rainfed olive orchards.

ESTIMATION OF CARBON SEQUESTRATION FROM OLIVE TREE GROVES IN THE ISLAND OF CRETE, GREECE

Tree plantations remove atmospheric carbon through photosynthesis, assisting in climate change mitigation. Olive oil is the main agricultural product produced in the island of Crete, Greece. The role of olive groves in carbon removal in the island has not been investigated so far. The current work aims in evaluating the annual carbon sequestration in Crete from olive groves. Existing data regarding carbon removal rate from olive trees have been used combined with the cultivated area of olive tree orchards in Crete. The annual carbon removal rate in olive groves is at 2.5 tC/ha while the area of olive tree plantations in Crete is estimated at 142,900 ha. The annual carbon sequestration rate due to olive groves in Crete is estimated at 1,310,393 tCO2 or 1.92 tCO2 per capita. This is compared with 3.03 tCO2 per capita emitted during electricity generation in the island and 0.14 tCO2 per capita emitted due to heating oil use in heating buildings. It corresponded at 32.54 % of the total CO2 emissions per capita in the country in 2017. The results indicate that carbon sequestration due to olive groves in Crete is not negligible and it should be taken into account in designing the appropriate policies for reducing the carbon footprint in the island.

SOCIAL AND PRIVATE PROFITABILITY OF TREE-BASED ADAPTATION OPTIONS TO CLIMATE CHANGE IN A DRYLAND AREA OF TUNISIA

Climate change exacerbates the effects of water scarcity on livelihoods. Governments can intervene by structuring incentives for agricultural adaptations so that farmers can choose the ones that create more benefits for the society as a whole. This requires consideration of a range of different benefits to different groups within the social cost-benefit analysis (CBA). We assess the social and private profitability of two alternative tree-based adaptation techniques that have received state support in the traditional barley cropping/rangeland systems in Central Tunisia: olive tree plantation, and intercropping with cactus. The results showed that society does not benefit from offering incentives for olive production. The production of irrigated olive trees without incentives is profitable for farmers and for society, while rainfed plantation is not profitable at all. However, it is possible for farmers to increase their incomes without increasing agricultural water use if they are encouraged to adopt intercropping with cactus to supplement livestock food and watering. The findings highlight scope for policies to balance between returns both for society, and for farmers, as revealed through the application of quantitative social CBA.

Analysing the combined effect of wetted area and irrigation volume on olive tree transpiration using a SPAC model with a multi-compartment soil solution

In this paper, we analyse the combined effect of wetted area and irrigation volume and its impact on olive tree transpiration (E p) after validating a multi-compartment SPAC model in a drip-irrigated hedgerow olive tree plantation. Modelled E p is compared with 2 years of calibrated sap flow records under two different irrigation treatments: a control (C) that was watered using a crop coefficient (K c) of 0.75 and a regulated deficit irrigation (RDI) in which applied irrigation was gradually reduced in relation to the K c of the control (50, 25 and 20% from June to August). The simulated midday leaf water potential (Ψ l) was also compared with measurements performed twice a month in each treatment and for both years. The model accurately predicted E p in both years for the two treatments (R 2 = 0.81 and RMSE = 0.29 mm/day), while midday Ψ l was slightly underestimated. Simulation analysis showed that (a) the use of drip irrigation systems always limits the maximum attainable E p for a given environment; and (b) irrigation design should depend on available water. If irrigation water is limited, the wetted area should be minimized to reduce losses from soil evaporation, thus maximizing the water devoted to E p; by contrast, if water is available, the maximum E p would be reached when wetting at least 30–40% of tree space. The model was accurate enough to capture the trends in E p and Ψ l of trees submitted to different irrigation regimes.

Assessment of carbon sequestration and the carbon footprint in olive groves in Southern Spain

ABSTRACTTree plantations are characterized by their ability to remove CO2 from the atmosphere and store it in a stable manner in tree structures (trunks, roots and branches) as well as in the soil. The study was conducted in Southern Spain in olive groves and covering an area of 1121 ha, where 22 homogenous plantation units were selected. The Picual and Arbequina varieties were assessed in intensive, super-intensive and conventional plantations as well as in rainfed and irrigated plantations. The net carbon (C) balance in the olive tree plantations was clearly positive, especially in intensive and super-intensive plantations (2.05 and 4.10 Mg C ha–1 yr–1 on average for all plantations studied). These results are significant for life-cycle evaluations of olive oil and for obtaining the C footprint of olive oil as a final product. Improved practices for soil management, such as the use of conservation tillage and cover crops and reincorporating pruning residues into the soil, can notably increase the net C balance in tree plantations and may even double it in amount. Thus, including the C sequestration rate of olive tree plantations can increase the accuracy of C footprint estimations for olive oil and represents a key factor in marketing the final product according to its environmental benefits.

Iberian lynx (Lynx pardinus) breeding in olive tree plantations

Abstract At the turn of the 21st century, <100 Iberian lynx (Lynx pardinus) individuals were found to occur in Southern Spain. Research conducted when the species was that scarce identified Mediterranean scrubland as its breeding habitat. In recent years, the population has grown both in number of individuals and occupied surface. Here, we describe the use of olive tree plantations with low scrub density as breeding habitats by the Iberian lynx. Our results suggest that habitats that were formerly considered as non-suitable, such as agricultural land, could indeed host Iberian lynx breeding territories in areas with low scrubland coverage if wild rabbits are abundant.

Ecological focus area – EFA: the biological value of olive groves. A case study in Sardinia (Italy)

Among the CAP (Common Agricultural Policy) 2015-2020 innovations, a mandatory ‘greening’ component of direct payment has been included to improve sustainable and environmentally friendly agricultural practices in arable lands. Permanent crops1 are considered as ‘greening’ by definition and therefore exempted from additional agronomic duties. So far, however, an adequate knowledge of the real biological value of permanent crops is still lacking. In the present work, realized in the context of the MO.NA.CO. project, we monitored animal diversity in olive-groves characterized by three different managements (from low to medium intensity). Monitoring was carried out in Sardinia (Italy), using different animal groups as bio-indicators: Arthropods, Reptiles and Birds. Considering Arthropod orders and Coleopteran families we did not found significant differences in the overall abundance and in the biodiversity indexes. However, faunal composition clearly varied among managements: moreover, the higher or lesser presence of certain taxa highlighted the existence of microenvironmental variables that may be related, for instance, to the level of soil vegetation cover or to the degree of naturalness of the agroecosystem. Limitedly to the Arthropod diversity, the comparison with other land uses (including data gathered in previous projects) showed a good potentiality of olive groves as ‘ecological focus areas’, at least considering the managements here examined. The monitoring of Reptiles and Birds showed the peculiarity of the olive groves located in a hilly area characterized by non-intensive management, which hosted a rich herpetofauna and a bird community typical of habitats characterized by a high degree of naturalness. The present monitoring provides data for the assessment of the biological value of olive groves and of the potential impact of different managements on faunistic diversity. Future monitoring is needed to improve the knowledge on olive tree plantations characterized by high intensive management.

Towards an optimized method of olive tree crown volume measurement.

Accurate crown characterization of large isolated olive trees is vital for adjusting spray doses in three-dimensional crop agriculture. Among the many methodologies available, laser sensors have proved to be the most reliable and accurate. However, their operation is time consuming and requires specialist knowledge and so a simpler crown characterization method is required. To this end, three methods were evaluated and compared with LiDAR measurements to determine their accuracy: Vertical Crown Projected Area method (VCPA), Ellipsoid Volume method (VE) and Tree Silhouette Volume method (VTS). Trials were performed in three different kinds of olive tree plantations: intensive, adapted one-trunked traditional and traditional. In total, 55 trees were characterized. Results show that all three methods are appropriate to estimate the crown volume, reaching high coefficients of determination: R2 = 0.783, 0.843 and 0.824 for VCPA, VE and VTS, respectively. However, discrepancies arise when evaluating tree plantations separately, especially for traditional trees. Here, correlations between LiDAR volume and other parameters showed that the Mean Vector calculated for VCPA method showed the highest correlation for traditional trees, thus its use in traditional plantations is highly recommended.

Effect of Different Irrigation Levels on the Yield and Traits of Memecik Olive Trees ( Olea europaea L.) in the Aegean Coastal Region of Turkey

AbstractAlthough olive trees are well known to be resistant to drought, the economic advantages of irrigation have been clearly demonstrated. Today, the olive growing areas in the Mediterranean Basin suffer from water shortages and increased competition from other sectors for the available water resources. This study was conducted in an olive tree plantation in western Turkey in 2008–2010. In the study, the effects of different irrigation levels on yield and the physiological and morphological development of olive trees (Olea europaea L. cv. Memecik) were investigated, and the optimal irrigation schedule was determined according to the findings of the study. Six different irrigation treatments were created using a drip irrigation system. The treatments were: a control (SC) in which irrigation amounts were scheduled based on the soil moisture content of the top 90 cm of root depth by the gravimetric method and five treatments that received an amount of water equivalent to 25% (S0.25), 50% (S0.50), 75% (S0....

Estimation of wood volume and height of olive tree plantations using airborne discrete-return LiDAR data

The aim of this study is to analyze methodologies based on airborne LiDAR (light detection and ranging) technology of low pulse density points (0.5 m−2) for height and volume quantification of olive trees in Viver (Spain). A total of 29 circular plots, each with a radius of 20 m, were sampled and their volumes and heights were obtained by dendrometric methods. For these estimations, several statistics derived from LiDAR data were calculated in each plot. Regression models were used to predict volume and height. The results showed good performance for estimating volume (R2 = 0.70) and total height (R2 = 0.67).

Determination of Crop Water Stress Index and Irrigation Timing on Olive Trees Using a Handheld Infrared Thermometer

Leaf temperature has long been recognized as an indicator of water availability. The stress level in a plant can be quantified from leaf temperature by using the crop water stress index (CWSI). In this study, it was investigated whether infrared thermometer measurements and accordingly CWSI could be used to create irrigation schedules for olive trees (cultivated variety Memecik). The research was conducted at the olive tree plantation of the Olive Research Station between 2009 and 2010. In the study, the effects of different irrigation treatments on the yield, canopy temperature, and CWSI of olive trees were investigated, and the optimum irrigation schedule was determined according to the findings. Seven different water application treatments were created using the drip irrigation method. Five treatments consisted of irrigating at a rate equivalent to 25% (S-0.25), 50% (S-0.50), 75% (S-0.75), 100% (S-1.00), and 125% (S-1.25) of the cumulative evaporation in 5 days from a Class A evaporation pan. The other two treatments consisted of a treatment in which the humidity lost at a soil depth of 0–90 cm was replenished each time to the field capacity (Control, S-C) and a treatment in which no irrigation was performed and cultivation was carried out under completely rain-based conditions (Stress, S-0). In the study, the amounts of irrigation water applied to the treatments ranged from 0 to 809 mm, and the crop water consumption values varied from 127 to 853 mm according to the average of both years. The highest water-use efficiency was obtained in the S-0 treatment, whereas the highest irrigation water–use efficiency was obtained from the S-0.50 treatment. One of the important findings of this study was that handheld infrared thermometer can be used for stress detection and irrigation scheduling of olive trees. When the mean CWSI values in the experimental years were examined in terms of the irrigation treatments, the CWSI values ranged from 0 to 0.68 in 2009 and from 0.02 to 0.71 in 2010. In both years, the highest values were recorded in the S-0 treatment, and the lowest values in the S-1.25 treatment. When water-use efficiency is evaluated along with CWSI values, irrigation can be recommended at half of the evaporation from a Class A evaporation pan (S-0.50, when CWSI values reach 0.39). In conditions in which water sources are insufficient, it can be recommended that irrigation be started when evaporation is a quarter (S-0.25), that is, when CWSI values reach 0.49.

Site-specific management in an olive tree plantation

Yield and soil mapping were carried out in 2007 and 2008 in a 9.1 ha commercial olive tree plantation for olive oil production. The orchard is in the southern Peloponnese, where olives are cultivated extensively for extra virgin olive oil production. The field is planted in rows with about 1650 trees in total. Weed control was practiced during the previous 3 years using post emergence herbicides under no-tillage over about 2/3 of the field, and over the remaining 1/3 by mechanical weeding using a rotary cultivator. For yield mapping, olives were collected manually using rods to shake the tree shoots and letting the olives fall onto a plastic net covering the ground. Sacks of approximately 58 kg capacity were filled with olives from as many adjacent trees as were needed to fill a sack. The location of the sacks, or group of closely placed sacks, was identified using a commercial GPS (5 m resolution). In addition, 91 cores of soil were taken at a depth of 0–30 cm on a 30-m systematic sampling grid corresponding to a density of 10 soil samples per ha. The soil properties measured were penetration resistance, soil texture, organic matter, pH, P, NO3–N, K, Mg, Zn, Mn, Fe, B and Ca contents. The effect of the method of weed control on the soil condition for post emergence herbicides under no-tillage versus rotary cultivation was evaluated on the basis of soil organic matter content and penetration resistance. The data were analyzed using both descriptive statistics and geostatistical methods. Maps were created as a basis for site-specific management of P, K and lime, and these were applied 15 days after harvest in the winter of 2008. The results indicated considerable spatial variation in yield and soil properties. The soil organic matter content was about 22% greater and the penetration resistance about 26% less in the areas under no-tillage. The mean pH increased from 5.9 to 7.0 as a result of lime application in the areas with pH below 6.5.