ReDivia - Repositorio Digital de l'Instit Valencià d'Investigacions Agràries
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Combination of antifungal edible coatings and MA packaging for postharvest preservation of fresh `Mollar de Elche´ pomegranates
Get PDFSpontaneous Plants Improve the Inter-Row Soil Fertility in a Citrus Orchard but Nitrogen Lacks to Boost Organic Carbon
Get PDFThe inter-row soils in conventionally run citrus orchards in Eastern Spain lose fertility, either physically, chemically, or biologically, as a consequence of machinery traffic and the use of herbicides. In order to regain inter-row soil fertility, two grass-cover management alternatives to the commonly used herbicide-kept bare management, namely, spontaneous plants and fescue, were established and left for four years until their effects on several physical, chemical, and biological parameters were monitored for two years more. The fescue ground cover exhibited lower average and maximum soil temperatures due to higher evapotranspiration rates but also higher annual soil water content on average and, additionally, higher rhizodeposition. Despite the fact that these new beneficial conditions helped enhance the soil’s biological fertility under fescue, the physical or chemical fertilities did not improve and neither did the organic carbon (SOC). The spontaneous plants also enhanced the biological fertility, but in this case, beneficial conditions were reflected by improvements in the chemical fertility, particularly the exchangeable potassium, and in the physical fertility by increasing the surface hydraulic conductivity and decreasing the bulk density. In the
inter-rows of this citrus orchard, a seeded grass cover does not seem able to provide any soil fertility enhancement in comparison to a spontaneous one; rather the opposite. However, a lack of natural or man-driven nitrogen inputs poses a constraint to SOC gains. For this aim, the annual surface application of organic nitrogen-rich materials or even better, the fostering of N-fixing organisms would be recommended
Mechanical Pruning of ‘Clemenules’ Mandarins in Spain: Yield Effects and Economic Analysis
Get PDFPruning is one of the most expensive tasks in citrus production, and its mechanization could increase the productivity and competitiveness of citrus farms. The effect of mechanical pruning on yield depends on the variety, crop condition, and location; among other factors. The ‘Clemenules’ mandarin variety is one of the most important ones; therefore, the aim of this work was to study the effects of twelve pruning strategies on ‘Clemenules’ yield over four years, and to conduct an economic analysis. These strategies included fully manual pruning, annual alternation of mechanical/manual pruning, mechanical pruning with manual follow-up, and fully mechanical pruning with different types of cuttings. The results showed that pruning strategies affected the yield and fruit size in some years of the study but not when the four years overall are considered. Strategies that annually alternated mechanical pruning with manual pruning had higher yields than the fully mechanical approaches, and similar yields to the manual and control (no pruning) strategies. Furthermore, although the mechanical pruning costs per hectare were as minimum two times less than those with manual pruning, higher net value was achieved with the manual pruning approach followed by alternate annual mechanical/manual pruning. In conclusion, after four years of study, the pruning strategy with the best global results for ‘Clemenules’ mandarin was that which involved annually alternating mechanical (topping and one-sided hedging) and manual pruning. This strategy allows maintaining regular tree dimensions without dry branches inside
Xylella fastidiosa Infection Reshapes Microbial Composition and Network Associations in the Xylem of Almond Trees
Get PDFXylella fastidiosa represents a major threat to important crops worldwide including almond, citrus, grapevine, and olives. Nowadays, there are no efficient control measures for X. fastidiosa, and the use of preventive measures and host resistance represent the most practical disease management strategies. Research on vessel-associated microorganisms is gaining special interest as an innate natural defense of plants to cope against infection by xylem-inhabiting pathogens. The objective of this research has been to characterize, by next-generation sequencing (NGS) analysis, the microbial communities residing in the xylem sap of almond trees affected by almond leaf scorch disease (ALSD) in a recent X. fastidiosa outbreak occurring in Alicante province, Spain. We also determined community composition changes and network associations occurring between xylem-inhabiting microbial communities and X. fastidiosa. For that, a total of 91 trees with or without ALSD symptoms were selected from a total of eight representative orchards located in five municipalities within the X. fastidiosa-demarcated area. X. fastidiosa infection in each tree was verified by quantitative polymerase chain reaction (qPCR) analysis, with 54% of the trees being tested X. fastidiosa-positive. Globally, Xylella (27.4%), Sphingomonas (13.9%), and Hymenobacter (12.7%) were the most abundant bacterial genera, whereas Diplodia (30.18%), a member of the family Didymellaceae (10.7%), and Aureobasidium (9.9%) were the most predominant fungal taxa. Furthermore, principal coordinate analysis (PCoA) of Bray–Curtis and weighted UniFrac distances differentiated almond xylem bacterial communities mainly according to X. fastidiosa infection, in contrast to fungal community structure that was not closely related to the presence of the pathogen. Similar results were obtained when X. fastidiosa reads were removed from the bacterial data set although the effect was less pronounced. Co-occurrence network analysis revealed negative associations among four amplicon sequence variants (ASVs) assigned to X. fastidiosa with different bacterial ASVs belonging to 1174-901-12, Abditibacterium, Sphingomonas, Methylobacterium–Methylorubrum, Modestobacter, Xylophilus, and a non-identified member of the family Solirubrobacteraceae. Determination of the close-fitting associations between xylem-inhabiting microorganisms and X. fastidiosa may help to reveal specific microbial players associated with the suppression of ALSD under high X. fastidiosa inoculum pressure. These identified microorganisms would be good candidates to be tested in planta, to produce almond plants more resilient to X. fastidiosa infection when inoculated by endotherapy, contributing to suppress ALSD
Consumers’ Visual Attention and Choice of ‘Sustainable Irrigation’-Labeled Wine: Logo vs. Text
Get PDFGrowing consumer awareness about the environmental impact of their food purchase decisions means having to create labels that better communicate sustainability aspects. The aim of this study is to explore consumers’ responses to “sustainable irrigation” (SI)-labeled wine. To this end, the effect of two label factors, SI claims (no SI info, logo, and text), and their position (front- vs. back-labels) on consumer choice, reasons for choice, perceived sustainability, and willingness-to-pay is determined. Moreover, we determine, for the first time, for SI claims, the relationship between consumer choice and paid attention. Our results reveal that almost 90% of the 408 consumers participating in this study show an interest in the SI-labeled wines. The main reason for choosing the SI-labeled wines rather than the control (no SI info-label) was the following: ‘I think it’s more environmentally friendly’, with an increase of two points on a nine-point sustainability perception scale. Consumers prefer the logo-label to the text-label, mainly because they find it more attractive, and a close relationship between paid attention and product choice probability is determined. The vast majority of consumers are willing to pay an extra cost of 15% or more for SI-labeled wine vs. the control. These results have relevant implications for the industry because they show that the SI logo is a useful way to draw consumers’ attention to the sustainability of irrigation practices and positively affect their choice. Our findings indicate that this way of differentiating the product in the market can contribute to compensating the economic cost of implanting SI practices
Characterization of the Spanish Pomegranate Germplasm Collection Maintained at the Agricultural Experiment Station of Elche to Identify Promising Breeding Materials
Get PDFPomegranates were one of the first domesticated fruit crops, and their long history resulted in the development of local cultivars all over the world. Spain is one of the main producers and exporters of this crop in the Mediterranean Basin, but in order to maintain the competitiveness of this crop, new varieties should be developed. For this purpose, the pomegranate germplasm collection hold at the Agricultural Experiment Station of Elche, a public institution dependent on the Valencian regional government, is an interesting tool. However, the detailed characterization of any germplasm collection is a fundamental requirement to be able to make the most of these resources, allowing to identify putative promising accessions and to optimize the design of the future crosses. In this work, the genetic diversity of 94 accessions of this collection was analyzed using 19 microsatellite markers. As a result, 85 different genotypes were identified. These genetic profiles could be useful for varietal identification. Despite this genetic diversity, no clear substructure was observed, except for the ornamental accessions, that could be related to the vegetative propagation of the species. Additionally, the morphological characterization of this collection has made it possible to identify some materials that may be of interest as a source of traits for breeding. Results presented here pave the way for further genetic analyses, allowing the selection of parents to obtain segregating populations, as well as their descendants by the use of molecular assisted selection
Desarrollo de recubrimientos comestibles con aditivos alimentarios antifúngicos para el control de Penicilliun spp. y la conservación de mandarina ‘Orri’
Get PDFRecubrimientos comestibles compuestos a base de goma arábiga (AG), hidroxipropilmetilcelulosa (HPMC) o almidón de patata (S) en combinación con cera de abeja (BW), gliceril monoestearato (GME) o cera de carnauba (CW) fueron formulados con dos aditivos alimentarios o sales GRAS (‘generally recognized as safe’) con propiedades antifúngicas: benzoato de sodio (SB, 2% p/p) o sorbato de potasio (PS, 2% p/p). Los efectos de los recubrimientos sobre la calidad de mandarinas ‘Orri’ se evaluaron tras un almacenamiento a 20 ºC de 14 días. Posteriormente, se evaluó la actividad curativa de los recubrimientos seleccionados en el control de las podredumbres verde y azul, causadas respectivamente por Penicillium digitatum y P. italicum, en mandarinas inoculadas artificialmente 24 h antes e incubadas a 20 ºC durante 7 días. Las emulsiones a base de AG con BW y CW mostraron valores bajos de viscosidad (4,54-26,34 mPa·s), pero aumentaron la pérdida de peso (WL) de las mandarinas. Las formulaciones a base de HPMC-BW y HPMC-CW fueron estables, con valores de viscosidad de 18 mPa·s, pero aportaron poco brillo. El recubrimiento a base de S-GME, con viscosidad de 58,91 mPa·s, redujo significativamente la WL sin afectar negativamente la apariencia de la fruta. La adición de PS a los recubrimientos aumentó significativamente la WL del fruto. El recubrimiento S-GME con 2% SB fue el más efectivo para controlar las podredumbres causadas por Penicillium spp. y redujo la incidencia y la severidad de las enfermedades en un 40 y 35%, respectivamente. Además, redujo también la WL de las mandarinas durante el almacenamiento a 20ºC, lo que demuestra su potencial para la conservación de la mandarina ‘Orri’ en poscosecha
The zoophytophagous predator Pilophorus clavatus (Hemiptera: Miridae) induces plant defences in citrus
Get PDFThe zoophytophagous mirid Pilophorus clavatus has been recently identified inhabiting citrus orchards in the Mediterranean region, where it feeds on several important citrus pests. In this work, we investigated whether the plant feeding by P. clavatus could induce defensive responses in citrus plants. Here, we show for the first time that the P. clavatus herbivory triggers the accumulation of the stress-related hormones salicylic acid (SA) and jasmonic acid (JA) in citrus plants. Moreover, the SA and JA pathways enhanced plant defence mechanisms as the expression of genes encoding enzymes from both biosynthetic and responsive pathways were upregulated in P. clavatus-punctured plants. We also investigated whether the induced defences could affect the plant host selection of Tetranychus urticae and the predatory mites Phytoseilus persimilis and Neouseiulus californicus. Neither T. urticae nor N. californicus preferred the odour source emitted by intact or P. clavatus-punctured plants in a Y-tube olfactometer assay. However, P. persimilis were significantly attracted to P. clavatus-induced plants. The performance of T. urticae was also compared when mites were released on control or previously P. clavatus-induced plants. Compared to the control, the infestation of T. urticae was significantly reduced up to 70% on those citrus plants previously activated by P. clavatus. Our results show for the first time that feeding of P. clavatus on citrus plants can have a dual beneficial effect due to its known predatory action and, at the same time, by inducing the plant’s immune system
Biología y ecología del trips de la orquídea Chaetanaphothrips orchidii (Moulton) (Thysanoptera: Thripidae) en cítricos
Get PDFEl trips de la orquídea Chaetanaphothrips orchidii (Moulton) (Thysanoptera: Thripidae) es uno de los trips más dañinos en los cítricos españoles. Los daños producidos por C. orchidii fueron detectados por primera vez en España en el otoño de 2016. Desde 2019, se ha estudiado la biología, ecología y enemigos naturales de este trips para mejorar su gestión integrada en cítricos
Evaluación preliminar de extractos de piel de granada para el control de las podredumbres marrón y amarga en nectarinas
Get PDFLas podredumbres marrón y amarga, causadas respectivamente por los hongos Monilinia fructicola y Geotrichum candidum, generan importantes pérdidas económicas en la poscosecha de fruta de hueso. Para el control de dichos patógenos, en la actualidad se emplean fungicidas de síntesis, como el fludioxonil y el pirimetanil. Sin embargo, debido al perjuicio sobre el medio ambiente y la salud humana que puede ocasionar la acumulación de este tipo de sustancias, se necesitan estrategias de control alternativas no contaminantes, como es la aplicación de extractos naturales vegetales. Numerosos estudios han reportado la actividad antimicrobiana de los extractos de la piel de granada (Punica granatum L.), atribuidos principalmente a su elevado contenido en polifenoles