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The olive tree is crucial to the Mediterranean agricultural economy but faces significant threats from climate change and soil-borne pathogens like Verticillium dahliae. This study assesses the dual role of an onion extract formulation, rich in organosulfur compounds, as both biostimulant and antifungal agent. Research was conducted across three settings: a controlled climatic chamber with non-stressed olive trees; an experimental farm with olive trees under abiotic stress; and two commercial olive orchards affected by V. dahliae. Results showed that in the climatic chamber, onion extract significantly reduced MDA levels in olive leaves, with a more pronounced reduction observed when the extract was applied by irrigation compared to foliar spray. The treatment also increased root length by up to 37.1% compared to controls. In field trials, irrigation with onion extract increased the number of new shoots by 148% and the length of shoots by 53.5%. In commercial orchards, treated trees exhibited reduced MDA levels, lower V. dahliae density, and a 26.7% increase in fruit fat content. These findings suggest that the onion extract effectively reduces oxidative stress and pathogen colonization, while enhancing plant development and fruit fat content. This supports the use of the onion extract formulation as a promising, sustainable alternative to chemical treatments for improving olive crop resilience. [ABSTRACT FROM AUTHOR]

Trunk injection applies more nutrients in the correct volume and composition, delivering ideal results with fewer fertilizer treatments under drought-stress conditions. We used a completely randomized block design to examine the effects of trunk injection therapy on the development of drought stress tolerance in olive trees in arid climates. Treatments included seaweed extract (SWE), potassium amino acid chelate (PAC), calcium silicate (CS), and potassium silicate (PS) at five different concentrations: 0.25, 0.5, 1, 2, and 4% for each treatment. Each treatment consisted of four replications – four dry replications for each treatment and four irrigation controls – each receiving weekly irrigation. The findings showed that, in comparison to drought control, trunk injection of PAC at a concentration of 2% enhances the relative water content of leaf and proline and decreases electrolyte leakage (EL) and malondialdehyde (MDA) content. Chlorophyll a, carotenoids, and proline content are all significantly higher in the trunk after CS injection at a 4% concentration than in the control treatment. MDA and EL were also reduced. Injecting PS leads to an increase in proline and photosynthetic pigments. The SWE treatment improved the proline, relative leaf water content, and photosynthetic pigments. To sum up, trunk injection treatments under drought conditions improved plant photosynthetic pigments, increased proline content, prevented relative water content reduction, and prevented an increase in MDA and EL. In conclusion, among the several treatments, the use of 2% PS was the most effective at reducing the adverse effects of drought stress on olive plants. [ABSTRACT FROM AUTHOR]

The fungi Botryosphaeriaceae are involved in olive declines in both the world hemispheres and in all continents where this species is cultivated. In Salento (Apulia, Italy), the Botryosphaeriaceae Neofusicoccum mediterraneum and N. stellenboschiana have been reported as the agents of a branch and twig dieback that overlaps with olive quick decline syndrome caused by Xylella fastidiosa subsp. pauca. In this study, we report the finding of Diplodia seriata, another Botryosphaeriaceae species, in Salento in Xylella fastidiosa-infected olive trees affected by symptoms of branch and twig dieback. Given that its presence was also reported in olive in the Americas and in Europe (Croatia) with different degrees of virulence, we were prompted to assess its role in the Apulian decline. We identified representative isolates based on morphological features and a multilocus phylogeny. In vitro tests showed that the optimum growth temperature of the isolates is around 25–30 °C, and that they are highly thermo-tolerant. In pathogenicity trials conducted over eleven months, D. seriata expressed a very low virulence. Nonetheless, when we imposed severe water stress before the inoculation, D. seriata significatively necrotized bark and wood in a time frame of 35 days. Moreover, the symptoms which resulted were much more severe in the trial performed in summer compared with that in autumn. In osmolyte-supplemented media with a water potential from −1 to −3 Mpa, the isolates increased or maintained their growth rate compared with non-supplemented media, and they also grew, albeit to a lesser extent, on media with a water potential as low as −7 Mpa. This suggests that olives with a low water potential, namely those subjected to drought, may offer a suitable environment for the fungus' development. The analysis of the meteorological parameters, temperatures and rainfall, in Salento in the timeframe 1989–2023, showed that this area is subjected to a progressive increase of temperature and drought during the summer. Thus, overall, D. seriata has to be considered a contributor to the manifestation of branch and twig dieback of olive in Salento. Coherently with the spiral decline concept of trees, our results suggest that heat and drought act as predisposing/inciting factors facilitating D. seriata as a contributor. The fact that several adverse factors, biotic and abiotic, are simultaneously burdening olive trees in Salento offers a cue to discuss the possible complex nature of the olive decline in Salento. [ABSTRACT FROM AUTHOR]

The olive tree (Olea europaea) and olive oil hold significant cultural and historical importance in Europe. The health benefits associated with olive oil consumption have been well documented. This paper explores the mechanisms of the anti-cancer effects of olive oil and olive leaf, focusing on their key bioactive compounds, namely oleocanthal, oleacein, and oleuropein. The chemopreventive potential of oleocanthal, oleacein, and oleuropein is comprehensively examined through this systematic review. We conducted a systematic literature search to identify eligible articles from Scopus, PubMed, and Web of Science databases published up to 10 October 2023. Among 4037 identified articles, there were 88 eligible articles describing mechanisms of chemopreventive effects of oleocanthal, oleacein, and oleuropein. These compounds have the ability to inhibit cell proliferation, induce cell death (apoptosis, autophagy, and necrosis), inhibit angiogenesis, suppress tumor metastasis, and modulate cancer-associated signalling pathways. Additionally, oleocanthal and oleuropein were also reported to disrupt redox hemostasis. This review provides insights into the chemopreventive mechanisms of O. europaea-derived secoiridoids, shedding light on their role in chemoprevention. The bioactivities summarized in the paper support the epidemiological evidence demonstrating a negative correlation between olive oil consumption and cancer risk. Furthermore, the mapped and summarized secondary signalling pathways may provide information to elucidate new synergies with other chemopreventive agents to complement chemotherapies and develop novel nutrition-based anti-cancer approaches. [ABSTRACT FROM AUTHOR]

We explored the activation of defense genes and the changes in volatile profiles in olive (Olea europaea var. Picual) plants subjected to mechanical wounding and prior soil inoculation with the fungus Trichoderma afroharzianum T22. Our findings indicate a sustained effect of the inoculant in olive plants, which shifted the constitutive volatile emission more significantly towards an aldehyde-dominated blend than the mechanical damage alone. Furthermore, we found that wounding alone did not alter the expression of hydroperoxide lyase genes associated with aldehyde biosynthesis. However, this expression was significantly enhanced when combined with prior T22 inoculation. Mechanical wounding amplified the plant's immediate defensive response by enhancing the upregulation of the direct defense enzyme acetone cyanohydrin lyase. Trichoderma afroharzianum T22 also modulated direct defense, although to a lesser extent, and its effect persisted 9 months after inoculation. Metagenomic analyses revealed that aerial mechanical damage did influence specific root bacterial functions. Specifically, an upregulation of predicted bacterial functions related to various metabolic processes, including responses to biotic and abiotic stresses, was observed. On the contrary, T22's impact on bacterial functional traits was minor and/or transient. [ABSTRACT FROM AUTHOR]

In Tunisia, the olive is the most cultivated fruit crop in the northern region, where annual rainfall exceeds 400 mm. This olive-growing area is characterized by a wide coverage of marginal soil with a high slope gradient. Therefore, the inclusion of cover crops in olive orchards is a sustainable solution to enhance ecosystem productivity, improve soil fertility, and increase oil yields. This study aimed to investigate the short-term (two cropping seasons in 2021 and 2022) effects of different seeded cover crops and soil management practices on soil characteristics, as well as soil health by measuring soil enzyme activities and microbial diversity. Six cover crop types consisting of wheat, vetch, oat, fenugreek, a vetch–oat mixture, and spontaneous vegetation were tested in association with rainfed olive trees (cv. Chetoui) in the north of Tunisia and compared to a control (which was tilled periodically three times per year without intercropping). During the first cropping season, cover crops were cut as animal feed, and only residues were incorporated into the soil. However, during the second year, all cover crop biomass was incorporated into the soil. The results indicated that the dry biomass production and carbon uptake were significantly higher in grass species (wheat and oat). All of the cover crops, including the spontaneous vegetation, significantly increased soil organic matter (SOM) and macronutrient levels, mainly, available phosphorus. On the other hand, the highest level of soil nitrogen was found in the fenugreek cover crop. The soil enzyme activities in the cover crops of wheat, oat, and the vetch–oat mix were higher than those in the control. Together with the increase in soil organic matter (SOM), this demonstrates a significant improvement in soil health with cover crops. Furthermore, this study proves that the utilization of carbon sources was dominated by amides, amines, and amino acids in the fenugreek plot, while it was dominated by polymers and carboxylic acids in the case of the wheat and oat. Overall, this study demonstrates that seeding cover crops is a sustainable management practice not only to integrate livestock but also to improve soil health in semiarid olive orchards. [ABSTRACT FROM AUTHOR]

This systematic review explores the role of remote sensing technology in addressing the requirements of sustainable olive growing, set against the backdrop of growing global food demands and contemporary environmental constraints in agriculture. The critical analysis presented in this document assesses different remote sensing platforms (satellites, manned aircraft vehicles, unmanned aerial vehicles and terrestrial equipment) and sensors (RGB, multispectral, thermal, hyperspectral and LiDAR), emphasizing their strategic selection based on specific study aims and geographical scales. Focusing on olive growing, particularly prominent in the Mediterranean region, this article analyzes the diverse applications of remote sensing, including the management of inventory and irrigation; detection/monitoring of diseases and phenology; and estimation of crucial parameters regarding biophysical parameters, water stress indicators, crop evapotranspiration and yield. Through a global perspective and insights from studies conducted in diverse olive-growing regions, this review underscores the potential benefits of remote sensing in shaping and improving sustainable agricultural practices, mitigating environmental impacts and ensuring the economic viability of olive trees. [ABSTRACT FROM AUTHOR]

The olive tree is a significant woody crop in the Mediterranean basin, with the primary olive-growing areas located in the south and southwest of the Iberian Peninsula. Climate plays a crucial role in crop distribution, viability, production, and yield. The climatic and topographical conditions of Extremadura in southwestern Spain, were analysed to characterise and group the olive-growing areas. To achieve this, a Geographic Information System (GIS) was developed to locate all registered olive tree plots. The orientations and elevations of these were analysed, along with the average, minimum, and maximum temperatures, precipitation, and frost for the period of 1990–2021. The study reveals that olive groves in Extremadura are primarily situated at elevations ranging from 200 to 600 m above sea level. Additionally, it was found that the least common orientation is towards the north. Temperatures are not a constraint for olive growing, except in the mountainous areas in the north of the region; however, rainfall can be a limiting factor. In fact, 50% of the olive-growing area receives less rainfall than is considered adequate for optimal production. Frost days and the low probability of severe frosts are not a problem for olive growing in this region, except in the highest parts of the region. The scale of this study, at plantation level, will enable the implementation of measures aimed at climate change adaptation and mitigation. [ABSTRACT FROM AUTHOR]

Olive anthracnose is the most important fungal disease of the olive fruit worldwide, with the fungus Colletotrichum acutatum as the main cause of the disease in Greece. A total of 11 commercial biological plant protection products (bioPPPs) (Amylo-X®, Botector®, FytoSave®, LBG 01F34®, Mevalone®, Polyversum®, Remedier®, Serenade® ASO, Sonata®, Trianum-P®, Vacciplant®), with various modes of action against the fungus C. acutatum, were evaluated by bioassays using detached fruits of two important olive Greek varieties, cv. Koroneiki and cv. Kalamon. Subsequently, the most effective bioPPPs were evaluated for their ability to induce plant defense mechanisms, by determining the expression levels of ten Olea europaea defense genes (Pal, CuaO, Aldh1, Bglu, Mpol, Lox, Phely, CHI-2, PR-10, PR-5). Remedier®, Trianum-P®, Serenade® ASO, Sonata®, and Mevalone® were the most effective in reducing disease severity, and/or inhibiting the conidia production by the fungus at high rates. Post bioPPPs application, high expression levels of several olive plant defense genes were observed. This study provides insights into commercial bioPPPs' effectiveness in controlling olive anthracnose, as well as biocontrol-agents-mediated modulation of olive defense mechanisms. [ABSTRACT FROM AUTHOR]

The olive fruit fly (Bactrocera oleae Rossi) is the most dangerous pest of olive fruits and negatively influences the chemical and sensory quality of the oil produced. Organic farms have few tools against this pest and are constantly looking for effective and sustainable products such as geomaterials, i.e., zeolite. Since a particle film covers the canopy, a study was carried out on the olive tree's responses to zeolite foliar coating. The tested treatments were natural zeolite (NZ), zeolite enriched with ammonium (EZ), and Spintor-Fly® (SF). EZ was associated with higher photosynthetic activity with respect to the other treatments, while no differences were found between SF and NZ. Foliar treatments affect the amount of BVOC produced in both leaves and olives, where 26 and 23 different BVOCs (biogenic volatile organic compounds) were identified but not the type of compounds emitted. Foliar treatment with EZ significantly affected fruit size, and the olive fruit fly more frequently attacked the olives, while treatment with NZ had olives with similar size and attack as those treated with Spintor-Fly®; no difference in oil quantity was detected. Oil produced from olives treated with NZ presented higher values of phenolic content and intensities of bitterness and spiciness than oils from those treated with EZ and SF. According to the results of this study, using zeolite films on an olive tree canopy does not negatively influence plant physiology; it has an impact on BVOC emission and the chemical and sensory characteristics of the oil. [ABSTRACT FROM AUTHOR]

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The olive tree is crucial to the Mediterranean agricultural economy but faces significant threats from climate change and soil-borne pathogens like Verticillium dahliae. This study assesses the dual role of an onion extract formulation, rich in organosulfur compounds, as both biostimulant and antifungal agent. Research was conducted across three settings: a controlled climatic chamber with non-stressed olive trees; an experimental farm with olive trees under abiotic stress; and two commercial olive orchards affected by V. dahliae. Results showed that in the climatic chamber, onion extract significantly reduced MDA levels in olive leaves, with a more pronounced reduction observed when the extract was applied by irrigation compared to foliar spray. The treatment also increased root length by up to 37.1% compared to controls. In field trials, irrigation with onion extract increased the number of new shoots by 148% and the length of shoots by 53.5%. In commercial orchards, treated trees exhibited reduced MDA levels, lower V. dahliae density, and a 26.7% increase in fruit fat content. These findings suggest that the onion extract effectively reduces oxidative stress and pathogen colonization, while enhancing plant development and fruit fat content. This supports the use of the onion extract formulation as a promising, sustainable alternative to chemical treatments for improving olive crop resilience.

The olive tree (Olea europaea) and olive oil hold significant cultural and historical importance in Europe. The health benefits associated with olive oil consumption have been well documented. This paper explores the mechanisms of the anti-cancer effects of olive oil and olive leaf, focusing on their key bioactive compounds, namely oleocanthal, oleacein, and oleuropein. The chemopreventive potential of oleocanthal, oleacein, and oleuropein is comprehensively examined through this systematic review. We conducted a systematic literature search to identify eligible articles from Scopus, PubMed, and Web of Science databases published up to 10 October 2023. Among 4037 identified articles, there were 88 eligible articles describing mechanisms of chemopreventive effects of oleocanthal, oleacein, and oleuropein. These compounds have the ability to inhibit cell proliferation, induce cell death (apoptosis, autophagy, and necrosis), inhibit angiogenesis, suppress tumor metastasis, and modulate cancer-associated signalling pathways. Additionally, oleocanthal and oleuropein were also reported to disrupt redox hemostasis. This review provides insights into the chemopreventive mechanisms of O. europaea-derived secoiridoids, shedding light on their role in chemoprevention. The bioactivities summarized in the paper support the epidemiological evidence demonstrating a negative correlation between olive oil consumption and cancer risk. Furthermore, the mapped and summarized secondary signalling pathways may provide information to elucidate new synergies with other chemopreventive agents to complement chemotherapies and develop novel nutrition-based anti-cancer approaches.

The fungi Botryosphaeriaceae are involved in olive declines in both the world hemispheres and in all continents where this species is cultivated. In Salento (Apulia, Italy), the Botryosphaeriaceae Neofusicoccum mediterraneum and N. stellenboschiana have been reported as the agents of a branch and twig dieback that overlaps with olive quick decline syndrome caused by Xylella fastidiosa subsp. pauca. In this study, we report the finding of Diplodia seriata, another Botryosphaeriaceae species, in Salento in Xylella fastidiosa-infected olive trees affected by symptoms of branch and twig dieback. Given that its presence was also reported in olive in the Americas and in Europe (Croatia) with different degrees of virulence, we were prompted to assess its role in the Apulian decline. We identified representative isolates based on morphological features and a multilocus phylogeny. In vitro tests showed that the optimum growth temperature of the isolates is around 25–30 °C, and that they are highly thermo-tolerant. In pathogenicity trials conducted over eleven months, D. seriata expressed a very low virulence. Nonetheless, when we imposed severe water stress before the inoculation, D. seriata significatively necrotized bark and wood in a time frame of 35 days. Moreover, the symptoms which resulted were much more severe in the trial performed in summer compared with that in autumn. In osmolyte-supplemented media with a water potential from −1 to −3 Mpa, the isolates increased or maintained their growth rate compared with non-supplemented media, and they also grew, albeit to a lesser extent, on media with a water potential as low as −7 Mpa. This suggests that olives with a low water potential, namely those subjected to drought, may offer a suitable environment for the fungus’ development. The analysis of the meteorological parameters, temperatures and rainfall, in Salento in the timeframe 1989–2023, showed that this area is subjected to a progressive increase of temperature and drought during the summer. Thus, overall, D. seriata has to be considered a contributor to the manifestation of branch and twig dieback of olive in Salento. Coherently with the spiral decline concept of trees, our results suggest that heat and drought act as predisposing/inciting factors facilitating D. seriata as a contributor. The fact that several adverse factors, biotic and abiotic, are simultaneously burdening olive trees in Salento offers a cue to discuss the possible complex nature of the olive decline in Salento.

This study evaluates the economic and environmental effects of replacing inorganic fertilization with organic fertilization (manure and compost) in three characteristic crops of the rainfed land of southeastern Spain: almond, olive, and barley. To do this, the conventional cultivation model of the three production systems was established and analyzed through the LCC (Life Cycle Costing) and LCA (Life Cycle Assessment) methodologies. Next, a sensitivity analysis was performed to see the effects of the substitution. In the three conventional systems, inorganic fertilizers represent at least 11% of the total costs. At the same time, they are the element with the greatest global contribution to environmental impacts (between 60 and 88%). Through the sensitivity analysis, it was shown that tillage practices that involve the addition of manure or compost not only reduce costs for the three crops (with a maximum reduction of EUR 88/ha in the case of olive trees with compost application), but also most of the impact categories evaluated. In terms of global warming, the reduction varies from 2–9% depending on the crop and the organic fertilizer used. And if we take into account that the production of inorganic fertilizers is avoided, the results of this category decrease between 28% and 48%. [ABSTRACT FROM AUTHOR]

The aim of this article was to provide a comprehensive review of the factors that influence the risk of pests in olive cultivation on a global scale. Two different analytical methods were used: a bibliometric review and a systematic review. The first method, based on the Scopus database and supported by analytical tools such as VOSviewer and Bibliometrix, allowed for the identification and analysis of 1060 publications, with a particular focus on the 445 most cited from 2014 to 2023. This bibliometric exploration highlighted the main contributions and trends in research on pest management in olive growing. On the other hand, the systematic review was carried out through a triangulation of databases, including Scopus, EBSCO, and Web of Science, following the PRISMA protocol to ensure a rigorous methodological process. A total of 27 scientific studies were selected that provided a detailed and relevant view of pest control practices. The results of this systematic analysis show the critical importance of the controlled and judicious use of pesticides in olive cultivation to prevent adverse effects on human health, biodiversity, and the environment. They also highlight the need to promote sustainable cultivation practices that reduce dependence on agrochemicals, thereby improving soil health and the quality of the harvested product. [ABSTRACT FROM AUTHOR]

The rising demand for olive oil worldwide led to an increase of oil production, causing an undesired side-effect such as the huge quantity of olive mill wastewater (OMWW) and leaf waste, which represent a serious problem in agriculture. The present work aims to recycle these wastes and use them as fertilizer in nurseries for young olive trees. Hence, three treatments of OMWW were used: i) Photocatalytic treatment (PT) by silicon dioxide nanoparticles; ii) Biological treatment (BT) by olive leaves and iii) a combination of both biological and photocatalytic treatments (CT). The obtained results showed that BT and PT, when used separately, reduced the phenolic content (PC) and chemical oxygen demand (COD), compared to raw OMWW. Interestingly, by combining both treatments, the removal rate of PC and COD reached 78% and 66%, respectively. Following the amendment of young olive trees by treated OMWW, plants growth and morphology, photosynthetic machinery and antioxidant capacity were improved compared to those amended with raw OMWW, with the best values observed under CT. In conclusion, CT allowed the bioremediation of two olive by-products that are useful as biofertilizer for olive young plants in a short period of time and at low cost. [ABSTRACT FROM AUTHOR]

Soil degradation and climate change are threatening the sustainability of Mediterranean olive orchards, typically grown under rainfed conditions and conventional soil tillage. Thus, implementing sustainable soil management practices is crucial to preserve soil health and mitigate the negative effects on plant performance. In this study, we assessed the effects of conventional tillage (T), an early maturing and self-reseeding annual legume cover crop (LC) and its combination with natural zeolites (ZL) on plant physiological performance, tree nutritional status, crop yield, and soil physicochemical and microbiological properties. Although both LC and ZL enhanced the photosynthetic activity, tree nutritional status, soil moisture and olive yield relative to T, ZL was clearly more efficient at improving some soil health indicators, namely at the 0–10 cm soil layer, once soil acidity decreased and Kjeldahl N, extractable P and B, cation exchange capacity and microbiological activity increased, as evidenced by the higher concentrations of easily extractable and total glomalin-related soil protein, microbial biomass carbon, microbial biomass quotient, and actinomycetes. Therefore, using natural zeolite with leguminous cover crops appears to be a promising strategy of sustainable soil management in rainfed olive orchards, as it is able to provide numerous ecosystem services. [ABSTRACT FROM AUTHOR]

The climate change has negative effects on crop production worldwide. The scarcity of water in semi-arid zones proper the use of biostimulants to improve yield and quality parameters. The present work evaluated the impact of exogenous spraying with moringa leaves aqueous extract (MLE 5%) on agro-physiological behavior of the olive cultivar "Arbequina" conducted in super high density during two growing seasons (2019–2020). The experiment consisted of six treatments (T0 = 100% ETc; T1 = 100% ETc + 5% MLE; T2 = 75% ETc; T3 = 75% ETc + 5% MLE; T4 = 50% ETc; and T5 = 50% ETc + 5% MLE). Twelve trees were considered for each treatment and distilled water was applied as control for the MLE treatment. Vegetative growth, yield, water status, antioxidants, oil parameters, leaf gas exchange, and chlorophyll fluorescence were analyzed. Results showed that the net photosynthesis (Pn), stomatal conductance (gs), and evapotranspiration (E) varied significantly in response to drought stress and MLE treatments. The two water regimes (100% and 75% ETc) showed similar behavior regarding the agro-physiological responses to the applied treatments, whereas the 50% ETc water regime significantly affected the studied parameters. The MLE was effective in mitigating the water stress on olive trees, by improving vegetative growth, yield, photosynthesis, and water productivity. It appears that trees grown under 75% ETc water regime were more responsive to 5% MLE, as they exhibit the highest yield (8.4 kg/tree), oil content (28.3%), and water use efficiency, whereas 25% of irrigation water was saved. [ABSTRACT FROM AUTHOR]

Xylella fastidiosa subsp. pauca (XFP), Neofusicoccum mediterraneum, N. stellenboschiana and other fungi have been found in olive groves of Salento (Apulia, Italy) that show symptoms of severe decline. XFP is well known to be the cause of olive quick decline syndrome (OQDS). It has also been assessed that Neofusicoccum spp. causes a distinct disease syndrome, namely, branch and twig dieback (BTD). All these phytopathogens incite severe symptoms that can compromise the viability of large canopy sectors or the whole tree. However, their specific symptoms are not easily distinguished, especially during the final stages of the disease when branches are definitively desiccated. By contrast, they can be differentiated during the initial phases of the infection when some facets of the diseases are typical, especially wood discoloration, incited solely by fungi. Here, we describe the typical symptomatological features of OQDS and BTD that can be observed in the field and that have been confirmed by Koch postulate experiments. Similar symptoms, caused by some abiotic adverse conditions and even by additional biotic factors, are also described. Thus, this review aims at: (i) raising the awareness that declining olive trees in Salento do not have to be linked a priori to XFP; (ii) defining the guidelines for a correct symptomatic diagnosis to orient proper laboratory analyses, which is crucial for the application of effective control measures. The possibility that bacterium and fungi could act as a polyspecies and in conjunction with predisposing abiotic stresses is also widely discussed. [ABSTRACT FROM AUTHOR]

Leaf spot symptoms were spotted in two olive orchards in Istria and in Kvarner Gulf, Croatia. Fungal species from three representative isolates (P13 LECIII, R18 BI, JA20 NP) have been morphologically characterized based on the colony and conidial characteristics. Several techniques were performed for inducing the sporulation of the JA20 NP isolate. Only PDA + banana medium was successful. PCR was conducted for ITS, TUB, and EF1α gene regions. Phylogenetic analyses were performed using internal transcribed spacer, beta-tubulin, and translation elongation factor 1-alpha sequence data. Three types of tests were conducted: a pathogenicity test on detached leaves, on detached and scratched leaves, and on olive seedlings. Ultimately, from the morphological characterizations, DNA sequence analysis of ITS, TUB, and EF1α gene regions, and phylogenetic analysis, these species were identified as Nigrospora gorlenkoana Novobr., Nigrospora osmanthi Mei Wang & L. Cai, and Nigrospora philosophiae-doctoris M. Raza, Qian Chen & L. Cai. This is the first report of Nigrospora species causing leaf spot on olive trees and the first report of Nigrospora philosophiae-doctoris as a plant pathogen. Fungal leaf diseases in conditions that are favorable for infection and disease development can lead to a decrease in the yield and olive oil quality. Therefore, it is necessary to conduct further research and the monitoring of fungal leaf diseases. [ABSTRACT FROM AUTHOR]

In this paper we present OLEAtool, a new software tool for palynological research to facilitate morphological analysis and measurements of Olea pollen. OLEAtool is a macro extension for use with ImageJ, an open-access and freely available image analysis software, and was developed as a component of the OLEA-project. This larger project examines olive tree expansion and mosaic landscape formation on the Balearic Islands. Pollen analysis of both fossil and modern grains has been proven useful for characterizing cultivars and therefore an important method for studying olive tree cultivation in the Mediterranean. However, these methods still struggle with distinguishing between wild and cultivated varieties. Traditional morphological analysis of pollen grains can be a difficult and time-consuming task. However, OLEAtool dramatically increases the speed of collecting data on pollen grains, expands the number of variables an analyst can measure, and greatly enhances the replicability of morphological analysis.

The survival of newly planted seedlings and their successful development after transplantation, including faster plant growth, improved plant quality, larger production, and the absence of dependence on arable land, is one of the primary goals of horticultural nurseries. Although peat is the most frequently used amendment in commercial potting substrates, exploiting it degrades essential ecosystems like peatlands and uses slowly renewable resources. This study evaluated the growth and nutrition of olive-rooted cuttings when peat was partially or completely replaced with vermicompost, searching for more sustainable methods and recovering urban wastewater treatment sludge sequentially. The progress of the plants’ growth was compared to that of corresponding plants in which commercial peat had been used as substrate. Leachates from every procedure were also examined, and the results revealed that trace element and heavy metal contents were much lower than those deemed hazardous for aquifers and soil. The outcomes indicated that peat might be effectively replaced with vermicompost sludge, promoting plant growth without further fertilizer. Comparatively to olive cuttings grown in peat-based substrates, those grown in compost-based substrates experienced improved nutrition and development. Further, it was found that irrigation doses were significantly reduced in treatments with a significant amount of vermicompost as the water drained more slowly. A technical-economic analysis was being conducted in the meantime, illustrating the financial benefits for a nursery when peat is replaced with vermicomposted sludge.

The olive tree is a significant woody crop in the Mediterranean basin, with the primary olive-growing areas located in the south and southwest of the Iberian Peninsula. Climate plays a crucial role in crop distribution, viability, production, and yield. The climatic and topographical conditions of Extremadura in southwestern Spain, were analysed to characterise and group the olive-growing areas. To achieve this, a Geographic Information System (GIS) was developed to locate all registered olive tree plots. The orientations and elevations of these were analysed, along with the average, minimum, and maximum temperatures, precipitation, and frost for the period of 1990–2021. The study reveals that olive groves in Extremadura are primarily situated at elevations ranging from 200 to 600 m above sea level. Additionally, it was found that the least common orientation is towards the north. Temperatures are not a constraint for olive growing, except in the mountainous areas in the north of the region; however, rainfall can be a limiting factor. In fact, 50% of the olive-growing area receives less rainfall than is considered adequate for optimal production. Frost days and the low probability of severe frosts are not a problem for olive growing in this region, except in the highest parts of the region. The scale of this study, at plantation level, will enable the implementation of measures aimed at climate change adaptation and mitigation.

The survival of newly planted seedlings and their successful development after transplantation, including faster plant growth, improved plant quality, larger production, and the absence of dependence on arable land, is one of the primary goals of horticultural nurseries. Although peat is the most frequently used amendment in commercial potting substrates, exploiting it degrades essential ecosystems like peatlands and uses slowly renewable resources. This study evaluated the growth and nutrition of olive-rooted cuttings when peat was partially or completely replaced with vermicompost, searching for more sustainable methods and recovering urban wastewater treatment sludge sequentially. The progress of the plants' growth was compared to that of corresponding plants in which commercial peat had been used as substrate. Leachates from every procedure were also examined, and the results revealed that trace element and heavy metal contents were much lower than those deemed hazardous for aquifers and soil. The outcomes indicated that peat might be effectively replaced with vermicompost sludge, promoting plant growth without further fertilizer. Comparatively to olive cuttings grown in peat-based substrates, those grown in compost-based substrates experienced improved nutrition and development. Further, it was found that irrigation doses were significantly reduced in treatments with a significant amount of vermicompost as the water drained more slowly. A technical-economic analysis was being conducted in the meantime, illustrating the financial benefits for a nursery when peat is replaced with vermicomposted sludge. [ABSTRACT FROM AUTHOR]

The recent COVID-19 pandemic caused by SARS-CoV-2 affected hundreds of millions of people and caused millions of deaths. There are few effective medications against SARS-CoV-2, and several studies attempted to make drugs based on natural components, such as olive leaves. Olive leaves are rich in polyphenolic compounds, which were proposed as a viable co-therapy supplement to treat and improve clinical symptoms in COVID-19 patients. Polyphenols have renown anti-inflammatory and multitarget antiviral effects on several virus families, which could be among the reasons of the beneficial effects of the Mediterranean diet against COVID-19. This scoping review is focused on the effect of olive tree polyphenols as a natural remedy to inhibit SARS-CoV-2, mainly discussing their influence on the process of viral entry into host cells by endocytosis. [ABSTRACT FROM AUTHOR]

Whole grains play a crucial role in the human diet. Despite being cultivated in distinct regions, they are shipped everywhere, therefore making biosafety and security essential throughout the grain industry, from harvest to distribution. Phytopathogens, which have an impact on crop yield, induce grain spoiling and reduce grain quality in a number of ways, providing a constant danger to crop storage and distribution. Chemical control approaches, such as the use of pesticides and fungicides, are detrimental to the environment and hazardous to human health. The development of alternative, environmentally friendly, and generally acceptable solutions to ensure increased grain yield, biosafety, and quality during storage is crucial in order to guarantee sufficient food and feed supplies. As a means of self-defense against microbial infection and spoilage, plant matrices feature antimicrobial natural chemicals, which have led to their widespread usage as food preservatives in recent decades. Olive tree extracts, known for their high polyphenol content, have been widely used in the food preservation industry with great success, and are highly welcomed by people all over the world. In addition to their well-known health advantages, polyphenols are a valuable plant secondary metabolite because of their great antibacterial capabilities as natural preservatives. This article discusses the promising usage of polyphenols from olive trees as a natural alternative preservative, while also highlighting the future of olive eaves in the food industry. [ABSTRACT FROM AUTHOR]

The global COVID-19 outbreak, started in December 2019, resulted in severe financial losses and extraordinary health crises. Finding a potent and secure medication candidate to treat SARS-CoV-2 infection and its symptoms is still an urgent global need. After reviewing previous studies, olive leaves, being rich in polyphenolic compounds (a large class of bioactive substances naturally found in plants), were proposed as a viable co-therapy supplement to treat and improve clinical symptoms in COVID-19 patients. It has long been known that olive tree polyphenols--such as oleuropein, hydroxytyrosol, verbascoside, as well as triterpenoids like maslinic, ursolic, and oleanolic acids--have anti-inflammatory and multitarget antiviral effects on several virus families, and they could be one of the reasons of the beneficial effects of the Mediterranean diet against COVID-19. Thus, olive tree polyphenols were tested in silico and in vitro for preventing SARS-CoV-2 infection, claiming that they have beneficial effects. Nevertheless, there is still a small number of research studies on this topic. The aim of this scoping review is to provide more information and offer an opinion on the feasibility of using olive tree polyphenols as a springboard for the creation of innovative natural remedies against this viral illness, ultimately planning future relevant studies. [ABSTRACT FROM AUTHOR]

Objective. In our study, we present the development of a novel cigarette filter enriched with polyphenols, with a particular focus on hydroxytyrosol extracted from olive sources. Our objective was to trap the presence of carcinogens in cigarette smoke by chemically modifying the filter surface. Materials and methods. To evaluate the filtration efficiency of the newly developed filter, we employed an automated Stain Pattern technique, enabling non-intrusive measurement of behavioral vent blocking. The surface modification of cigarette filters was meticulously carried out to target the reduction of nitrosamines formed during combustion. Results. Our extensive investigation underscores the potential of functionalizing cigarette filters using olive polyphenols, in particular hydroxytyrosol to mitigate the formation of harmful compounds, particularly nitrosamines, during smoking. Functionalized filters exhibited remarkable filtering efficiency, as evidenced by a capture factor (f=2.9×103) for two layers. Conclusions. This innovative approach has the capacity to revolutionize the utilization of filters in commercial cigarettes, significantly reducing consumers' exposure to toxic chemicals. Our research demonstrates that hydroxytyrosol-functionalized cigarette filters can effectively remove noxious substances like nitrosamines, offering a promising avenue for enhancing public health. Further in-depth research is essential to assess the protective impact of hydroxytyrosol-functionalized filters cigarettes, ensuring their potential to safeguard consumers' health effectively. [ABSTRACT FROM AUTHOR]

Olive pruning residues are a by-product that can be applied to soil or used for energy production in a circular economy model. Its benefits depend on the amount of pruning, which varies greatly within farms. This study aimed to investigate the spatial variability of shreddable olive pruning in a traditional olive grove in Córdoba (Spain) with an area of 15 ha and trees distanced 12.5 m from each other. To model the spatial variability of shreddable olive pruning, geostatistical methods of stochastic simulation were applied to three correlated variables measured on sampled trees: the crown projected area (n = 928 trees), the crown volume (n = 167) and the amount of shreddable pruning (n = 59). Pearson's correlation between pairs of variables varied from 0.71 to 0.76. The amount of pruning showed great variability, ranging from 7.6 to 76 kg tree−1, with a mean value of 37 kg tree−1. Using exponential and spherical variogram models, the spatial continuity of the variables under study was established. Shreddable dry pruning weight values showed spatial autocorrelation up to 180 m. The spatial uncertainty of the estimation was obtained using sequential simulation algorithms. Stochastic simulation algorithms provided 150 possible images of the amount of shreddable pruning on the farm, using tree projected area and crown volume as secondary information. The interquartile range and 90% prediction interval were used as indicators of the uncertainty around the mean value. Uncertainty validation was performed using accuracy plots and the associated G-statistic. Results indicate with high confidence (i.e., low uncertainty) that shreddable dry pruning weight in the mid-western area of the farm will be much lower than the rest of the farm. In the same way, results show with high confidence that dry pruning weight will be much higher in a small area in the middle east of the farm. The values of the G-statistic ranged between 0.89 and 0.90 in the tests performed. The joint use of crown volume and projected areas is valuable in estimating the spatial variability of the amount of pruning. The study shows that the use of prediction intervals enables the evaluation of farm areas and informed management decisions with a low level of risk. The methodology proposed in this work can be extrapolated to other 3D crops without requiring modifications. On a larger scale, it can be useful for predicting optimal locations for biomass plants, areas with high potential as carbon sinks or areas requiring special soil protection measures. [ABSTRACT FROM AUTHOR]

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Olive anthracnose is the most important fungal disease of the olive fruit worldwide, with the fungus Colletotrichum acutatum as the main cause of the disease in Greece. A total of 11 commercial biological plant protection products (bioPPPs) (Amylo-X®, Botector®, FytoSave®, LBG 01F34®, Mevalone®, Polyversum®, Remedier®, Serenade® ASO, Sonata®, Trianum-P®, Vacciplant®), with various modes of action against the fungus C. acutatum, were evaluated by bioassays using detached fruits of two important olive Greek varieties, cv. Koroneiki and cv. Kalamon. Subsequently, the most effective bioPPPs were evaluated for their ability to induce plant defense mechanisms, by determining the expression levels of ten Olea europaea defense genes (Pal, CuaO, Aldh1, Bglu, Mpol, Lox, Phely, CHI-2, PR-10, PR-5). Remedier®, Trianum-P®, Serenade® ASO, Sonata®, and Mevalone® were the most effective in reducing disease severity, and/or inhibiting the conidia production by the fungus at high rates. Post bioPPPs application, high expression levels of several olive plant defense genes were observed. This study provides insights into commercial bioPPPs’ effectiveness in controlling olive anthracnose, as well as biocontrol-agents-mediated modulation of olive defense mechanisms.

The olive fruit fly (Bactrocera oleae Rossi) is the most dangerous pest of olive fruits and negatively influences the chemical and sensory quality of the oil produced. Organic farms have few tools against this pest and are constantly looking for effective and sustainable products such as geomaterials, i.e., zeolite. Since a particle film covers the canopy, a study was carried out on the olive tree’s responses to zeolite foliar coating. The tested treatments were natural zeolite (NZ), zeolite enriched with ammonium (EZ), and Spintor-Fly® (SF). EZ was associated with higher photosynthetic activity with respect to the other treatments, while no differences were found between SF and NZ. Foliar treatments affect the amount of BVOC produced in both leaves and olives, where 26 and 23 different BVOCs (biogenic volatile organic compounds) were identified but not the type of compounds emitted. Foliar treatment with EZ significantly affected fruit size, and the olive fruit fly more frequently attacked the olives, while treatment with NZ had olives with similar size and attack as those treated with Spintor-Fly®; no difference in oil quantity was detected. Oil produced from olives treated with NZ presented higher values of phenolic content and intensities of bitterness and spiciness than oils from those treated with EZ and SF. According to the results of this study, using zeolite films on an olive tree canopy does not negatively influence plant physiology; it has an impact on BVOC emission and the chemical and sensory characteristics of the oil.

The agricultural sector in Morocco faces drought challenges due to limited water resources, necessitating the development of irrigation strategies targeted at increasing water production. In this regard, the olive sector can adopt deficit irrigation strategies, to achieve sustainable management practices that improve water productivity and save water used for irrigation. In pursuit of this aim, an experiment was carried out in an olive orchard over two consecutive years (2021 and 2022), comparing water productivity (WP) of four treatments of regulated deficit irrigation (RDI) and two treatments of sustained deficit irrigation (SDI), with fully irrigated trees. The results indicated that over time the RDI strategy, particularly in the T4 treatment, makes it feasible to conserve a substantial amount of irrigation water, approximately 40% during the phase when pit hardening occurs, and 20% during sensitive periods, all without compromising fruit yield. However, the SDI strategy, with its limited water availability, leads to a decline in the fruit yield of Menara olive trees. Out of these treatments, the SDI strategy led to the most substantial decrease in WP, with reductions ranging from 19% to 33% compared to the control T0.

Kuhn (1962) proposed an evolutionary model to explain how scientific knowledge is built, based on the concept of paradigm. Even though Kuhn's model is general, it has been applied to only a few topics in evolutionary biology, almost exclusively to broad-based paradigms. We analyze here, through the lens of Kuhn's theory, a small-scale paradigm change that occurred with the resolution of the controversy about the mating system of a Mediterranean shrub Phillyrea angustifolia (Oleaceae). We first summarize the different steps of the paradigm change and replace them in the more general context of sex ratio theory. Second, we show how the different steps of the paradigm change can be interpreted by Kuhnian concepts and tools. Finally, we discuss the actual and future status of the new paradigm. [ABSTRACT FROM AUTHOR]

This comparative study aims at highlighting the symbolism of the olive tree in Palestinian and Spanish poetry. Since the olive tree is elemental in both cultures, the study attempts to tackle four main themes of such a dominant tree: resistance, peace, eternity, and homeland. In order to conduct the study, a number of poems employing the olive tree are investigated and analyzed in order to highlight the closeness between the Palestinian and the Spanish cultures. The study tries to prove the matchfullness between the symbolism of the olive tree in both poetries. The selection of the poems is based on the common ground of the olive tree symbolism in Palestine and Spain. The only theme in which the poetry in the two cultures does not completely coincide is resistance. In Palestinian poetry, the olive is used to signify resistance against occupation, while this tree is employed to denote the resistance to socioeconomic classism, urban sprawl, and natural disasters. In order to make an outstanding comparison in the three other themes, the author selected poems of both cultures where the olive tree signifies international symbolizations. [ABSTRACT FROM AUTHOR]

It is essential to monitor the evolution of pollutants including heavy metals found in water intended for irrigation. Since they have a crucial impact on living beings. In this study, the contents of heavy metals were analyzed by ICP-AES on the three levels of irrigation water, soil and plants (olive tree and cardoon) and those in four different terrains. The Cd, Cu and Pd found in the water of the downstream Oued Fès and the treated wastewater are out of the norm. We found Pd in higher concentrations in both plants. For Cu it is more assimilated by the olive tree. Regarding the soil, the content of Cr is very high in the plot irrigated by water from Oued Fès located downstream and less high in the plot irrigated by treated wastewater. The cardoon of this last plot present an increased concentration in Cr more than the others. These variations depend on the type of plants and their different characteristics of absorption according also to the accumulation of metals in the soil adding also anthropic factors.

The main goal of this project consisted of the conceptualization and development of a product related to the olive tree chemical features to monetize the wastes of the olive fruit exploitation. The most abundant by-product of the olive fruit harvest is the olive leaves, used as the raw material in this project. By following the steps of Chemical Product Design, it was decided to pursue the idea of creating antibacterial cotton bed sheets impregnated with olive leaves extract, mainly composed of oleuropein. The production process includes a pre-treatment of the olive leaves, oleuropein extraction, and supercritical impregnation. The estimated amount of leaves required is 39 g/m2 of cotton, considering a cotton fabric with 115 GSM.

Under climate change threats, there is a growing need to adapt the conventional agronomic practices used in rainfed olive orchards by sustainable practices, in order to ensure adequate crop yield and olive oil quality and to preserve soil health. Therefore, for two years, the effects of conventional tillage practice (T) and two sustainable soil management strategies, a leguminous cover crop (LC) and its combination with natural zeolites (ZL), on the yield, fatty acid composition, polyphenolic profile and quality indices of olive fruits and oil were evaluated. Crop yield was significantly increased by LC and ZL in the first year. Although in the second year no significant differences were verified, the cumulative yield increased significantly by 31.6% and 35.5% in LC and ZL trees, respectively. LC enhanced the moisture and size of olives, while ZL increased, in general, the concentrations of oleuropein, verbascoside, caffeic acid and epicatechin, as well the oleic/linoleic ratio in fruits and the levels of 3,4-dihydroxyphenylglycol, tyrosol, verbascoside and caffeic acid in olive oil. Despite the higher concentration of total phenols in the fruits and oil from T trees in the warmer and dryer year, the quality of the oil decreased, mainly when compared with ZL, as evidenced by the peroxide value and K232 and K270 coefficients. In short, both sustainable soil management strategies appear to be promising practices to implement in olive orchards under rainfed conditions, but the innovative strategy of combining zeolites with legume cover crops, first reported in the present study, confers advantages from a nutritional and technological point of view. Nevertheless, studies subjected to the long-term use of these practices should be conducted to ensure the sustainability of the crop yield and olive oil quality. [ABSTRACT FROM AUTHOR]

For about a decade, olive groves in Apulia (Southern Italy) have been progressively destroyed by Olive Quick Decline Syndrome (OQDS), a disease caused by the bacterium Xylella fastidiosa subsp. pauca (Xfp). Recently, we described an additional wilting syndrome affecting olive trees in that area. The botryosphaeriaceous fungus Neofusicoccum mediterraneum was found associated with the diseased trees, and its high virulence toward olive trees was demonstrated. Given the common features with Branch and Twig Dieback (BTD) of olive tree, occurring in Spain and California, we suggested that the observed syndrome was BTD. During our first survey, we also found a botryosphaeriaceous species other than N. mediterraneum. In the present article, we report the morphological and molecular characterization of this fungal species which we identified as Neofusicoccum stellenboschiana. In the study, we also included for comparison additional N. stellenboschiana isolates obtained from olive trees in Latium and Tuscany region (Central Italy). The occurrence of N. stellenboschiana in olive trees is reported here for the first time in the northern hemisphere. The pathogenicity and virulence were tested in nine inoculation trials, where the Apulian N. stellenboschiana isolate was compared with the isolate from Latium and with the Apulian isolate of N. mediterraneum. Both isolates of N. stellenboschiana proved pathogenic to olive trees. They caused evident bark canker and wood discolouration when inoculated at the base of the stem of two/three-year-old trees and on one-year-old twigs. However, virulence of N. stellenboschiana was significantly lower, though still remarkable, compared with N. mediterraneum in term of necrosis progression in the bark and the wood and capacity of wilting the twigs. Virulence of N. stellenboschiana and N. mediterraneum did not substantially change when inoculations were performed in spring/summer and in autumn, suggesting that these fungal species have the potential to infect and damage olive trees in all seasons. The high thermotolerance of N. stellenboschiana was also revealed with in vitro growth and survival tests. The high virulence of these Botryosphaeriaceae species highlights their contribution in BTD aetiology and the necessity to investigate right away their diffusion and, possibly, the role of additional factors other than Xfp in the general decline of olive groves in Apulia. Hence the importance of assessing the degree of overlap of BTD/Botryosphariaceae with OQDS/Xfp is discussed. [ABSTRACT FROM AUTHOR]

Phytosanitary legislation involves government laws that are essential to minimize the risk of the introduction and diffusion of pests, especially invasive non-native species, as a consequence of the international exchange of plant material, thus allowing us to safeguard agricultural production and biodiversity of a territory. These measures ensure compliance with adequate requirements relating to the absence of pests, especially of harmful quarantine organisms through inspections and diagnosis tests of the consignments to ascertain the presence of the pests concerned. They also regulate the eradication and containment measures that are implemented in the eventuality of an unintentional introduction of these organisms. In the present contribution, the current plant protection legislation for the exchange of plants or propagation material within the European Union or for export to foreign countries, represented by Regulation (EU) 2016/2031, has been reviewed, with a particular focus on the olive tree (Olea europaea L.). Furthermore, a brief summary of the main olive tree pests transmissible with the propagation material is also reported, indicating their current categorization with respect to the relative quarantine status. [ABSTRACT FROM AUTHOR]

The olive tree has been a silent element of the chanson de geste of the Middle Ages. The Northern France has early developed an epic literature focused on the heroes of the Charles the Great's court (XII-XIII centuries). The paladins of the king are always engaged in the war against the infidels, both the Sarasin and the rebel vassals. In addition to the brave and the military strength, those wars require diplomacy and guile. Thus, before the battles, the king reunites the heroes under an olive tree in order to organize the war. The tree became an auspicious sign for the war; it had been charged of the religious symbolism that is based on the episode of Jesus Christ in the Garden of Gethsemane, the night of the Last Supper. The article will try to highlight the role of the olive tree in the chanson de geste, trying to highlight the different roles of the tree. [ABSTRACT FROM AUTHOR]

In this study, the diversity of thrips (Insecta: Thysanoptera) on two varieties of olive trees (Chemlal and Sigoise) in northeast Algeria (Province of Batna), was evaluated for 3 years (2019–2021). In addition, the fluctuations in the numbers of phytophagous thrips were estimated according to the varieties phenological stages. A total of 19 species are identified and the olive thrips (Liothrips oleae) have just been reported for the first time in Algeria. Only 5 females of this species were collected in May 2021 on the Sigoise variety at the fruit-setting stage. Haplothrips tritici(17.25%), Frankliniella occidentalis (16.29%) and Thrips tabaci (16.29%) are the most present. It is noticed that the thrips were present on the olive tree only in spring (April to May), when the average monthly temperatures are between 10–26 °C, but linear regression analyses were not confirmed that temperature explain the variation in thrips numbers, which may be due to other climatic factors such as the rainfall, while olive varieties and phenological stages are affecting the population of thrips, their number was higher on the Sigoise variety, especially at flowering stage in the case of H. tritici and F. occidentalis while T. tabaci was most noticeable at the fruit growth stage. The number of this species was relatively low, just until the inflorescence stage, where thrips start to appear in Sigoise before Chemlal. [ABSTRACT FROM AUTHOR]

This study deals jointly with three aspects of environmental, agricultural and energy sustainability: (a) Biogas is a booming energy source worldwide, resulting in an increasing production of digestate, its main by-product; (b) The extraction of peat, mainly used for nursery substrates, is being banned due to the destruction of natural habitats and release of GHGs; (c) Compost can represent a replacement of peat and contributes to the containment of GHGs. This study has verified how a compost obtained from digestate can be used as a substitute for peat in the nursery sector. While previous studies have evaluated compost use on just one species at a time, this study compared the same compost on two very different species: olive tree and hazelnut tree, both with growing interest for new tree plantings. Two concentrations of compost in the potting substrate of nursery seedlings were evaluated: 30% and 45% by weight, measuring the effect on some growth parameters during the growing season. The trials showed responses positive for olive and substantially negative for hazelnut: olive trees manifested better growth parameters with 45% compost, as opposed to hazelnut, where the addition of 45% compost worsened all growth parameters. A general conclusion can be drawn: in the nursery sector, compost can be used to replace peat, but this replacement can almost never be 100 percent, having instead to calibrate the percentage of replacement according to the characteristics of the compost and the individual edaphic needs of the plant species. [ABSTRACT FROM AUTHOR]