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Olive anthracnose, caused by Colletotrichum fungi, is responsible for major fruit yield losses and poor olive oil quality worldwide. In the Mediterranean basin, some Colletotrichum spp. appear to be replacing others, possibly due to climate change and modification in cultural systems. To update the situation in Portugal, 525 olive groves were surveyed throughout the country over two years, revealing a decrease in disease incidence, associated with scarcer rainfall and new cropping systems using less susceptible cultivars. A collection of 212 isolates was obtained, and phylogenetic analyses using a multi-locus sequencing approach (five and six loci in the acutatum and gloeosporioides species complex, respectively) revealed the presence of seven Colletotrichum species within the collection. Compared to surveys conducted in the first decade of the 21st century, the species composition of olive anthracnose pathogens in Portugal remains mostly unchanged, with C. nymphaeae as the prevalent species, followed by C. godetiae, but with C. acutatum geographically expanding and with C. alienum and C. cigarro being reported for the first time as causal agents of olive anthracnose in Portugal. A close attention to pathogen population shifts, in the context of climate change and modification of cultivation systems, is fundamental for anticipating plant protection measures. [ABSTRACT FROM AUTHOR]

Public health and environmental concerns are increasing the pressure to reduce chemical pesticide usage, thereby requiring management alternatives to control pest damage to crops. Retaining semi-natural habitats within agricultural landscapes is often assumed to be one such alternative, by contributing to boost natural enemy populations and reduce pest abundance and spread. However, these potential benefits might be diluted or counteracted by intensive field management, thus limiting their effectiveness. We test these hypotheses, focusing on olive farming in southern Portugal, where we quantified the abundance of three pests, the olive fruit fly (Bactrocera oleae), olive moth (Prays oleae) and olive psyllid (Euphyllura olivina), and their parasitism and infestation rates in 17 orchards representing an intensification gradient and varying landscape cover by oak woodlands. Fly infestation was lower in more intensive orchards, there were no woodland effects, and parasitism was never detected. Psyllid infestation was also lower in more intensive orchards, but declined with woodland cover in more intensive orchards, while slightly increasing in less intensive ones. Psyllid parasitism rate could not be confidently estimated. Moth infestation declined with woodland cover in the most intensive orchards, while varying little in less intensive orchards. Moth parasitism rate declined with intensification and increased with woodland cover, particularly in less intensive orchards. Infestation by the moth was positively related to its abundance, albeit less so when parasitism rates were higher. Overall, our findings show mixed effects of oak woodlands, although retaining such habitats might still enhance biocontrol potential and reduce pressure by some pests, even under management intensification. [ABSTRACT FROM AUTHOR]

In the northeast of Portugal, like in many parts of the world, most soils are acidic, which may hamper crop productivity. This study presents the findings of a factorial experiment on olive (Olea europaea L.) involving three factors: (i) soil type [schist (Sch) and granite (Gra)]; (ii) cultivars [Cobrançosa (Cob) and Arbequina (Arb)]; and (iii) fertilizer treatments [liming (CaCO3) plus magnesium (Mg) (LMg), phosphorus (P) application (+P), boron (B) application (+B), all fertilizing materials combined (Con+), and an untreated control (Con-)]. Dry matter yield (DMY) did not show significant differences between cultivars, but plants grown in schist soil exhibited significantly higher biomass compared to those in granite soil. Among the treatments, +B and Con+ resulted in the highest DMY (50.8 and 47.2 g pot−1, respectively), followed by +P (34.3 g pot−1) and Con- (28.6 g pot−1). Treatment LMg yielded significantly lower values (15.6 g pot−1) than Con-. LMg raised the pH above 7 (7.36), leading to a severe B deficiency. Although Con+ also raised the pH above 7 (7.48), it ranked among the most productive treatments for providing B. Therefore, when applying lime to B-poor sandy soils, moderate rates are advised to avoid inducing a B deficiency. Additionally, it seems prudent to apply B after lime application. [ABSTRACT FROM AUTHOR]

The presence of the South African Obscure Scale, Melanaspis corticosa (Brain) (Hemiptera, Diaspididae), was detected infesting olive trees, in Portugal. The identity of the scale insect was confirmed based on both morphological and molecular studies. Until now, this species was only known in a few African countries, including Guinea, Mozambique, South Africa and Zimbabwe. This is the first record of this species in Europe and in the Palearctic region. The scale was observed in 15 different locations, in the Algarve, since its first detection at the end of 2016. Samples were collected between 21 December 2016 and 10 March 2022, covering all seasonal periods. Most of the sampling sites resulted from private requests from farmers and proprietaries received by the Plant Protection Division of the Regional Directorate of Agriculture. Although it is considered a polyphagous species, it was not observed in other plant species, besides olive trees. The actual dispersion in the region suggests that M. corticosa became established and has been expanded its distribution since its arrival. This scale insect is a potential injurious pest of olive trees and needs to be studied to clarify its pest status and develop effective pest management strategies. [ABSTRACT FROM AUTHOR]

The soil infestation of Verticillium dahliae has significant Verticillium wilt of olive (VWO) with epidemiological consequences which could limit the expansion of the crop. In this context, there is a misunderstood history of the crops and soil property interactions associated with inoculum density (ID) increases in the soil. In this study, the effect of the combination of both factors was assessed on the ID of V. dahliae in the olive-growing areas of the Iberian Peninsula. Afterwards, the relationship of the ID to the mentioned factors was explored. The detection percentage and ID were higher in Spain than Portugal, even though the fields with a very favourable VWO history had a higher ID than that of the fields with a barely favourable history, regardless of the origin. The soil physicochemical parameters were able to detect the degree to which the ID was increased by the previous cropping history. By using a decision tree classifier, the percentage of clay was the best indicator for the V. dahliae ID regardless of the history of the crops. However, active limestone and the cation exchange capacity were only suitable ID indicators when <2 or 4 host crops of the pathogen were established in the field for five years, respectively. The V. dahliae ID was accurately predicted in this study for the orchard choices in the establishment of the olive. [ABSTRACT FROM AUTHOR]

The olive grove agroecosystem (Olea europaea L., Oleaceae) is very important in terms of economy and culture throughout the Mediterranean region. In Trás‐os‐Montes (Portugal), olive groves are commonly surrounded by semi‐natural areas consisting of Mediterranean shrublands. Understanding the role of potential predators of olive pests is crucial to enhancing biological control in sustainable agriculture. This study aimed to investigate the community structure of ground‐inhabiting spiders (Arachnida: Araneae) in the olive grove and their surrounding shrublands in Trás‐os‐Montes. We found that the community of spiders was dominated by ground hunters such as Lycosidae and Gnaphosidae. Lycosidae were more abundant in olive groves than in surrounding shrublands in 2015 only, whereas Gnaphosidae were more abundant in olive groves in both years of the study (2015 and 2016). Hence, the two habitats displayed a low complementarity of spider families. The Mediterranean shrubland areas could act as a reservoir and refuge for potential pest biocontrol agents. Conservation of surrounding semi‐natural areas may contribute to the natural limitation of pests exerted by spiders in the olive grove agroecosystem. Nevertheless, further long‐time and species‐level studies are needed to provide insights into the role of spiders as natural enemies. [ABSTRACT FROM AUTHOR]

The aim of this work was to study spatial and temporal distribution of Olea europeae airborne pollen in different Portuguese regions: Reguengos de Monsaraz (south); Bairrada (west); Braga (northwest); Valença do Douro and Foz Côa (northeast). Airborne pollen sampling was conducted from 1998–2003 using ‘Cour’ type samplers located in each region. The main pollen season (MPS) of Olea lasted on average 36 days and occurred from late April until middle-to-end of June. During the studied period, inter-annual variations among and within regions, concerning the total annual pollen counts and the beginning, peak and ending dates of the MPS, were reported. Reguengos de Monsaraz and Bairrada registered the earliest MPS starting date, followed by Valença do Douro and Foz-Côa, and the latest date was verified in Braga that also had the shortest MPS. Reguengos de Monsaraz presented the longest MPS with the highest differences in the beginning and ending dates, but minimum differences in the dates of the maximum pollen peak. Our results showed an increase in the Olea annual pollen index, from north to south, and from the west to the east regions of the country. [ABSTRACT FROM AUTHOR]

The cultivated Olea europaea L., or olive tree, is an ancient crop extremely relevant for the bioeconomy of Mediterranean countries, especially for Portugal. With orchard modernization, Portugal has the potential to become the third-largest producer of olive oil over the next decade. In this country, the main national variety is 'Galega vulgar,' characterized by an excellent olive oil quality, rusticity and tolerance to drought. Nevertheless, its production has suffered a reduction due to replacement by foreign varieties. The present narrative review offers an overall perspective of present gaps and challenges to the conservation and use of 'Galega vulgar.' Existing information about traditional and innovative olive production systems, and the importance of life cycle thinking approaches for a sustainable olive chain were synthesized, focusing particularly in the last 10 years. Furthermore, the olive molecular characterization advances and their breeding importance were also evaluated considering their application to this Portuguese variety. To ensure an efficient and sustainable exploitation of the 'Galega vulgar,' we propose that efforts should concentrate on the characterization of the existing variability and development of genotype to phenotype prediction tools, integrating detailed molecular marker genotypic and environmental characterization, to support better informed conservation and breeding decisions in a multi-environment context. [ABSTRACT FROM AUTHOR]

This study focused on the volatile changes in cv. Verdeal Transmontana throughout the entire olive oil processing chain, from the drupe to olive oil storage up to 12 months, while correlating it with quality parameters and sensory quality. During crushing and malaxation, the volatiles formed were mainly "green-leaf volatiles" (GLVs), namely (E)-2-hexenal, hexanal, and 1-hexanol. Centrifugation and clarification steps increased the total volatile amounts to 130 mg kg -1 . However, clarification also increased nonanal and (E)-2-decenal contents, two markers of oxidation, with a noticeable loss of phenolic compounds and oxidative stability. During storage, the total volatile amounts reduced drastically (94% at 12 months after extraction), together with the positive sensory attributes fruity, green, bitter, and pungent. Despite being classified as extra-virgin after one year of storage, peroxides and conjugated dienes were significantly higher while there was a reduction in antioxidant capacity as well as in phenolic compounds (less 50%) and oxidative stability (57%). The present work allowed concluding that the extraction process modulates the volatile composition of olive oil, with a concentration of volatiles at the clarification step. During storage, volatiles are lost, mainly eight months after extraction, leading to the loss of important sensory attributes., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

This study has been aimed at providing a qualitative and quantitative evaluation of selected phytochemicals such as phenolic acids, flavonoids, oleuropein, fatty acids profile, and volatile oil compounds, present in wild olive leaves harvested in Portugal, as well as at determining their antioxidant and cytotoxic potential against human melanoma HTB-140 and WM793, prostate cancer DU-145 and PC-3, hepatocellular carcinoma Hep G2 cell lines, as well as normal human skin fibroblasts BJ and prostate epithelial cells PNT2. Gallic, protocatechuic, p-hydroxybenzoic, vanillic acids, apigenin 7-O-glucoside, luteolin 7-O-glucoside, and rutin were identified in olive leaves. The amount of oleuropein was equal to 22.64 g/kg dry weight. (E)-Anethole (32.35%), fenchone (11.89%), and (Z)-3-nonen-1-ol (8%) were found to be the main constituents of the oil volatile fraction, whereas palmitic, oleic, and alpha-linolenic acid were determined to be dominating fatty acids. Olive leaves methanol extract was observed to exerted a significant, selective cytotoxic effect on DU-145 and PC-3 cell lines. Except the essential oil composition, evaluated wild olive leaves, with regard to their quantitative and qualitative composition, do not substantially differ from the leaves of other cultivars grown for industrial purposes and they reveal considerable antioxidant and cytotoxic properties. Thus, the wild species may prove to be suitable for use in traditional medicine as cancer chemoprevention., (© 2017 Wiley-VHCA AG, Zurich, Switzerland.)