Browsing by Author "Casquero, Pedro Antonio"
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- Adapting almond production to climate change through deficit irrigation and foliar kaolin application in a mediterranean climatePublication . Barreales, David; Capitão, Susana dos Anjos; Bento, Albino; Casquero, Pedro Antonio; Ribeiro, A.C.Irrigation is the best strategy to reduce the adverse effects of water stress on almond trees [Prunus dulcis (Mill) D.A. Web] and improve their productivity. However, in the current context of climatic change, in which the amount of water available for irrigation is increasingly limited, deficit irrigation (DI) strategies have become essential in the almond orchards of southern Europe. Other practices, such as the foliar application of reflective compounds, are being implemented. A three-year experiment (2019–2021) was set in a factorial design in which the effect of regulated deficit irrigation and foliar kaolin spray was evaluated on physiological (predawn leaf water potential, relative water content, leaf area, leaf gas exchange, and chlorophyll fluorescence) and agronomic parameters (yield, yield components, and water use efficiency (WUE)). The treatments include full irrigation (FI), which received 100% of ETc (crop evapotranspiration) during all irrigation seasons; regulated deficit irrigation (RDI), which received 100% of ETc until the kernel-filling stage, reducing the application to 35% ETc during the kernel-filling stage until harvest; and both irrigation regimes combined with kaolin application and two cultivars, Constantí and Vairo. More negative water potential values were observed in the RDI treatments compared to the FI treatments. There were no significant differences in the stomatal conductance, photosynthetic rate, or transpiration rate between treatments with RDI and FI, demonstrating the almond tree’s good adaptation to irrigation reduction in the kernel-filling stage. The two cultivars had different responses in cumulative yield throughout the three years of the trial. The cv. Constantí did not present significant differences between the FI and RDI treatments, translating into improved WUE. In contrast, the cv. Vairo suffered a reduction in accumulated performance in the RDI treatments with respect to the FI. The foliar application of kaolin did not present differences in yield and very few in the physiological activity of the almond trees. With the results obtained, we can suggest that under the conditions of our experiment, the combination of RDI and the kaolin foliar application can help save irrigation water and produce almonds more sustainably.
- Effectiveness of different traps and lures for coffee berry borer, Hypothenemus hampei (Ferrari, 1867) in Sao Tome IslandPublication . Carvalho, Maria Otília; Lopes, Ana Rita; Bento, Albino; Santos, Lucas; Guedes, Raul Narciso; Casquero, Pedro AntonioCoffee berry borer, Hypothenemus hampei (Ferrari, 1867), is a serious insect pest of organic coffee plantation in Sao Tome Island. To date, limited information regarding the seasonal phenology of this pest species on the islands limits the implementation of integrated pest management (IPM) programmes. As part of a coffee farmer training programme, three attractants were evaluated in red vs. transparent traps to assess olfactory and visual stimuli. The experiment was delineated in a split-block design with three types of attractants: commercial ethanol + 40 g of ripe Robusta coffee (A1), proportion 3:1 methanol and ethanol (A2), and commercial ethanol + 10 g of ground roasted Arabica coffee (A3); and two home- made transparent (D1) and red (D2) traps. The results showed that there was significant interaction between the trap model and the attractant for borer capture. The transparent trap baited with methanol and ethanol exhibited the best result with an average of 14.3 +/- 5.4 adults/trap/week. Transparent traps baited captured more borers and largest numbers of beetles were trapped late May through September. In short, home-made traps alone are not effective for controlling the coffee berry borer, but they are useful in monitoring this species.
- Effects of irrigation and collection period on grapevine leaf (Vitis vinifera L. var. Touriga Nacional): Evaluation of the phytochemical composition and antioxidant propertiesPublication . Barreales, David; Malheiro, Ricardo; Pereira, J.A.; Andrade, João Verdial; Bento, Albino; Casquero, Pedro Antonio; Ribeiro, A.C.The cultivation of grapevines (Vitis vinifera L.) has extended worldwide, with great economic importance. From this crop, we can obtain grapes for fresh consumption, raisins, juices, wine, and other derived products. The cultivation of grapevines also generates some byproducts, such as seeds, skins, wood and leaves. The leaves can be removed from the plant, as is common agricultural practice, to improve the production and quality of the grapes at certain periods in the crop cycle. In the present work, the phytochemical composition (total phenols content, hydroxycinnamic acids derivatives and flavonols) and antioxidant potential (reducing power, ABTS and DPPH radical scavenging capacity) of grapevine leaves from cv. Touriga Nacional were evaluated. The studied cultivar was under three severities of regulated deficit irrigation (RDI60, RDI40, and RDI20; providing 60, 40 and 20% of reference evapotranspiration, respectively) and non-irrigation (NI; exclusively rain-fed), in a vineyard located in the Demarcated Douro Region (Portugal). The leaves were collected at three different phenological stages: veraison, maturation, and grape harvest. For the first time, the interactions between different irrigation regimes and the collection period were evaluated on grapevine leaves. The results obtained for the phytochemical composition revealed that increasing irrigation reduced total phenols content, hydroxycinnamic acids derivatives, and flavonols in all of the phenological stages studied. For instance, compared to that of the control treatment (NI), the total phenols content reduced 19% in RDI20 (from 189 mg GAE g−1 to 153 mg GAE g−1), 28% in RDI40 (136 mg GAE g−1), and 33% in RDI60 (127 mg GAE g−1). The antioxidant activity suffered a reduction when the irrigation amount was increased for all assays. Additionally, the antioxidant activity suffered a reduction over time, presenting higher values in veraison. For harvest sampling, the loss of antioxidant activity was more notable, with EC50 values varying between 0.092 mg mL−1 (NI) and 0.187 mg mL−1 (RDI60). Altogether, the results suggest that grapevine leaves are a potential source of natural compounds with valuable antioxidant properties that could be explored by the pharmaceutical, chemical and food industries.
- Influence of deficit irrigation on grape quality and volatile compounds in the cultivars Touriga Nacional and Touriga Franca (Vitis vinifera L.) in the Douro Demarcated Region (Portugal)Publication . Barreales, David; Blanco-Ward, Daniel; Bento, Albino; Casquero, Pedro Antonio; Ribeiro, A.C.The effect of deficit irrigation on grape composition and volatile compounds in Touriga Nacional and Touriga Franca grapes (Vitis vinifera L.) was investigated over one growing season in the semi-arid sub-region Douro Superior of Douro Demarcated Region (RDD). The region is characterized by a Mediterranean climate, with very dry and warm summers that cause a strong water stress in most of the vineyards. The deficit irrigation tested corresponded to 25% of the reference evapotranspiration, compared to rainfed conditions. The irrigation started at the beginning of the veraison and ended at the harvest. We evaluated the yield and vigour per vine and the qualitative parameters of grapes and musts: berry weight and diameter, Ravaz index pH, total acidity, total soluble solids (ºBrix), total polyphenol index and volatile compounds. The volatile compounds were assessed by headspace solid-phase microextraction and gas chromatography–mass spectrometry (HS-SPME-GC/MS). The results indicate that the yield per vine was significantly higher in the irrigated plants. For Touriga Nacional there was an increase of 24.5% compared to rainfed vines (from 0.77 kg vine-1 to 1.02 kg vine-1) and for Touriga Franca an increase of 35.67% (from 1.10 kg vine-1 to 1.71 kg vine-1) was observed. For total soluble solids, in both varieties, higher values were obtained in rainfed grapes. Other quality parameters of the must also showed significant differences. With respect to volatile compounds, were identified and quantified mainly C6 compounds and others lipid-derived aldehydes and alcohols, terpenoids and esters. In general, higher amounts of volatile compounds were obtained in the rainfed grapevines. The results obtained could broaden our understanding of the deficit irrigation of grapevine in sub-region Douro Superior of RDD to find a balance between yield and quality grape. Furthermore, this kind of studies very important in a climate change scenario, expected for this region in the next decades.
- Lifecycle of Dryocosmus kuriphilus Yasumatsu and diversity and importance of the native parasitoid community recruited in the Northern Region of PortugalPublication . Lobo Santos, Ana; Santos, Sónia A.P.; Casquero, Pedro Antonio; Bento, AlbinoIn this work, the objective was to learn the life cycle of D. kuriphilus and the diversity of native parasitoids in the northern region of Portugal between 2017 and 2019. The places studied belonged to the regions of Entre-Douro-e-Minho, Beira Interior, and Tr & aacute;s-os-Montes. To achieve the proposed objectives, buds were collected for egg and larva observation, galls were collected for larva, pupa, and adult observation and monitoring, and emergency boxes were used to identify the fauna present in the galls. In this study, 92% of D. kuriphilus adults emerged between June and July, with emergences occurring until September. We also obtained adults in winter, so it is important to study, in future works, the hypothesis of this pest performing diapause. Regarding the study of native parasitoids, compared to other countries, the same families emerged, with good rates of natural parasitism, although with fluctuations over the years. In the three municipalities under study, 11 species were identified (Eupelmus azureus Ratzeburg, Eupelmus urozonus Dalman, Eurytoma brunniventris Ratzeburg, Megastigmus dorsalis (Fabricius), Ormyrus pomaceus (Geoffroy), Sycophila iracemae Nieves Aldrey, Sycophila variegata (Curtis), Sycophila biguttata (Swederus), Torymus flavipes (Walker), Torymus auratus (Mueller), and Torymus notatus (Walker)). The average parasitism rates varied between 1.92% and 10.68%.
- Mechanical behaviour of grapevine wood affected by Xylotrechus arvicolaPublication . Rodríguez-González, Álvaro; Casquero, Pedro Antonio; Pereira, J.A.; González-López, Óscar; Guerra, Marcos; García-González, Julia; Pozo, Julia M. Morán-Del; Juan-Valdés, AndrésThe cerambycid insect Xylotrechus arvicola is considered a pest that affects the wood of the grapevine (Vitis vinifera) in the major wine areas of the Iberian Peninsula. The larva of this insect perforates the grapevine wood, resulting in structural and biomechanical failure of the vine plants. Vine samples from wood damaged by X. arvicola larvae were picked up from different vineyards and grape varieties. Compressive and flexural tests were performed in order to assess the mechanical behaviour of the wood samples. Total length of the cracks in wood samples (TLCWS) that appeared on the surface of the grapevine wood samples after the mechanical tests was measured. Compressive strength (CS) and flexural strength (FS) decreased with the increase of the cross-sectional area (CSA) of both branches and trunks, regardless of damage condition or water content. Moreover, the resistance was lower in damaged wood. In addition, this was verified through the linear regression coefficients of the interaction CS x CSA and FS x CSA. TLCWS in branches and trunks of damaged samples was greater that in undamaged samples. Also, TLCWS within the same damage condition and part of the plant was higher in dry samples than in fresh samples. The damaged wood would show a higher vulnerability to common mechanical stress suffered by the grapevines in the field including heavy winds, fruit overweight or harvesting machines shaking (when mechanically collected). Larvae of this insect altered the mechanical behaviour of the trunk and branches of grapevine wood. The mechanical strength of wood was more negatively affected when the CSA of the branches and trunks increased. Longer TLCWS was found in affected wood.
- Regulatory non-coding RNAs in crops health and diseasePublication . Ferreira, Patrick; Casquero, Pedro Antonio; Choupina, AltinoFor many years it was thought that the function of RNA was limited to the process of producing proteins. In recent years, scientific discoveries have been proving the multiple roles of different RNAs in different regulatory mechanisms. These RNA’s are collectively called non-coding RNA’s (ncRNA’s). This review presents the latest advances on the different classes of non-coding RNA’s (ncRNA’s) from their function to mechanisms of action. Special emphasis is given to the long non-coding RNAs as new regulatory elements in eukaryote gene expression and in the processes of epigenetic regulation in plants. We believe that increasing studies of regulatory non-coding RNAs in plants will provide a better understanding of the different types of genes related to crop resistance