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Predicting the fundamental fluxes of an eddy-covariance station using machine learning methods
Full text linkMonitoring tools are needed to maximise living systems' ability to mitigate emissions and adapt to changing environmental conditions. Therefore, it is important to be able to predict the fundamental fluxes in crops, in this case vineyards, such as sensible heat flux (H), latent heat flux (LE) and carbon dioxide flux (CO2), in order to know their capacity to adapt to the environmental effects of climate change. In this study, Linear Regression (LR), Elastic Net (EN) regression, K-Nearest Neighbours (KNN), Gaussian-Process (GP), Decision Tree (TREE) Regression, Random Forest (RF) Regression, XGBoost (XGB) Regression, Support Vector Regression (SVR) and Multi-layer Perceptron (MLP) models have been applied to predict fundamental fluxes of an eddy-covariance station from conventional meteorological parameters. These models reproduced well the estimations of three output parameters from the eddy-covariance station. The performance of each predictive model was evaluated using Root-Mean-Squared Error (RMSE), Mean Absolute Error (MAE), Mean Square Error (MSE), Mean Absolute Percentage Error (MAPE), Mean Absolute Scaled Error (MASE) and the coefficient of determination (R2). The findings indicate that for the variable H, the GP model outperformed the SVR and all other models, achieving an R2 value of 0.99. Conversely, the SVR demonstrated superior performance for the variables LE and CO2, with R2 values of 0.96 for both. In summary, these findings suggest that the three models proposed show a robust performance in the prediction of the studied fluxes, underlining their versatility and adaptability to the various environmental conditions of the vineyard
High‑energy emulsification of Allium sativum essential oil boosts insecticidal activity against Planococcus citri with no risk to honeybees
Full text linkThe ecotoxicological consequences of synthetic pesticides have encouraged stakeholders to search for eco-friendly pest control tools, like essential oils (EOs). Nano-delivery systems (nanoparticles and nano-emulsions) seem ideal for developing EO-based biopesticides, although production processes should be standardized and implemented. In this study, nano-emulsions loaded with a high amount of Allium sativum L. EO (15%) were developed using different mixed bottom-up/top-down processes. Garlic EO was chemically analyzed by gas chromatography-mass spectrometry (GC-MS) and formulations were physically characterized using Dynamic Light Scattering (DLS) apparatus. The insecticidal activity against Planococcus citri Risso (Hemiptera: Pseudococcidae) and selectivity toward Apis mellifera L. (Hymenoptera: Apidae) worker bees was evaluated. Garlic EO was mainly composed of sulphur components (96.3%), with diallyl disulphide and diallyl trisulphide as the most abundant compounds (37.26% and 28.15%, respectively). Top-down processes could produce stable nano-emulsions with droplet size in the nanometric range (< 200nm) and good polydispersity index (PDI < 0.2). In contrast, the bottom-up emulsion was unstable, and its droplet size was around 500nm after 24 hours. High-energy emulsification processes significantly increased the residual toxicity of garlic EO against 3rd instar P. citri nymphs, whereas the developed formulations were harmless to A. mellifera workers in topical application. This study confirmed that the production process significantly affected the physical properties and efficacy against target pests. The lack of adverse impact on honeybees denotated the potential of these formulations as bioinsecticides in organic and/or IPM programs, although further extended ecotoxicological studies are necessary
Not just candy: A herbivore-induced defence-related plant protein in honeydew enhances natural enemy fitness
Full text linkHerbivore feeding often increases secondary metabolite production in plants. These herbivore-induced plant proteins might end up in honeydew excreted by phloem-feeding insects. This is important because honeydew is one of the most abundant and accessible carbohydrate sources for natural enemies in many agroecosystems and these proteins can thus mediate many tri-trophic interactions.
Here, we hypothesized that defensive metabolites induced in the phloem by herbivory accumulate in the honeydew excreted by phloem-feeding insects and, consequently, affect the fitness of the herbivores' natural enemies that feed on it.
We used a tri-trophic system consisting of citrus plants, the mealybug Planococcus citri and its primary parasitoid Anagyrus vladimiri. First, we assessed A. vladimiri fitness when fed on P. citri honeydew. We then collected honeydew of seven phloem-feeding insects, including P. citri, and analysed their protein content. Finally, we analysed the effect of superoxide dismutase (SOD), an antioxidant enzyme associated with plant defences that was commonly found in the analysed honeydews, on A. vladimiri fitness.
The fitness of A. vladimiri increased when fed on honeydew compared to a sucrose-based diet, demonstrating that honeydew can contain compounds that benefit natural enemies. Proteomic analyses showed that defence-related plant proteins were present in honeydew of seven phloem-feeding insects analysed. Among these, the enzyme SOD was present in honeydew of all of them. Moreover, the levels of SOD were 10-fold higher in the phloem of plants infested by P. citri than in that of uninfested plants. SOD was also actively excreted in P. citri honeydew, and we proved that it increases the fecundity of the parasitoid A. vladimiri.
We conclude that enzymatic proteins induced by herbivory in the phloem and involved in plant defence, accumulate in the honeydew excreted by phloem-feeding insects and, contrary to the current paradigm, at least some of these can have positive effects on the third trophic level
Enhancing anthracnose detection in mango at early stages using hyperspectral imaging and machine learning
Full text linkAnthracnose, caused by Colletotrichum sp. infections, poses a significant threat to mango production worldwide, resulting in substantial losses. This devastating disease is challenging to detect and control, primarily due to its ability to spread rapidly. The methods currently used to control anthracnose are primarily corrective, relying on disease detection in the late stages when the infection becomes visible. Hence, there is a need for tools to detect the infection at early stages, before symptoms appear. Hyperspectral imaging systems are promising for developing non-destructive solutions to assess and detect external and internal damage in fruit, including decay caused by anthracnose. These advanced imaging systems make early detection possible before the symptoms are visible, allowing for timely intervention and potentially more effective disease control. This work aims to evaluate the possibility of early detection of anthracnose in two mango cultivars using hyperspectral imaging and machine learning methods. Secondly, to establish correlations between specific wavelengths and the physicochemical symptoms associated with anthracnose. Lastly, to develop a robust model for the spectral detection of anthracnose on mango fruit. Mangoes were inoculated with spores of Colletotrichum gloeosporioides. Hyperspectral images of control and infected fruit were captured in the 450–970 nm spectral range. Five machine-learning models were used to obtain the method that best fits the spectral data. The best model achieved an accuracy = 0.961, recall = 0.961, specificity = 0.992, F1 = 0.961 and Matthews correlation coefficient (MCC) = 0.953 for 'Keitt', and an accuracy = 0.975, recall = 0.976, specificity = 0.995, F1 = 0.975 and MCC = 0.971 for 'Osteen', showing the feasibility to detect early anthracnose infection in mango fruit within 48 h after pathogen inoculation
Limpieza y mantenimiento de clones de boniato en el IVIA mediante cultivo in vitro de tejidos vegetales
No full textImpact of including two types of destoned olive cakes in pigs’ diets on fecal bacterial composition and study of the relationship between fecal microbiota, feed efficiency, gut fermentation, and gaseous emissions
Full text linkThe microbial population in the pig’s gastrointestinal tract can be influenced by incorporating fibrous by-products into the diets. This study investigated the impact of including two types of dried olive cake (OC) in pigs’ diets on fecal bacterial composition. The correlation between fecal microbiota and growth performance, nutrient digestibility, gut fermentation pattern and slurry gas emissions was also evaluated. Thirty male Pietrain x (Landrace x Large white) pigs (47.9 ± 4.21 kg) were assigned to three groups: a control group (C), a group fed a diet with 20% partially defatted OC (20PDOC), and a group fed a diet with 20% cyclone OC (20COC) for 21 days. Fecal samples collected before and after providing the experimental diets were analyzed for the V3-V4 region of the 16S rRNA gene. Pigs were weighed, and feed intake was recorded throughout the study. Potential ammonia and methane emissions from slurry were measured. No significant differences in alpha diversity indexes were found. The taxonomic analysis revealed that Firmicutes and Bacteroidota phyla were dominant at the phylum level across all groups. Differential abundance analysis using ALDEx showed significant differences among groups for various bacteria at the phylum, genus, and species levels at the end of the experiment. Pigs from 20PDOC and 20COC groups exhibited increased abundances of health-promoting bacteria, such as Plactomycetota at the phylum level and Allisonella and an unidentified genus from the Eggerthellaceae family at the genus level. These changes influenced short-chain fatty acids’ (SCFA) concentration in slurries, leading to greater acetic, butyric, caproic and heptanoic acids in OC-fed groups, especially 20COC pigs. A volatility analysis revealed significant positive correlations (p < 0.05) between Uncultured_Bacteroidales and Unculured_Selenomonadaceae and energy digestibility. Monoglobus and Desulfovibrio showed a positive significant (p < 0.05) correlation with total SCFA, indicating a high impact on gut fermentation. However, growth performance parameters and potential gas emission displayed no significant correlations with a specific bacterial genus. In conclusion, our results suggest that OC inclusion into pig diets could positively modulate and contribute to the gut microbiota’s favorable composition and functionality. Also, nutrient digestibility and gut fermentation patterns can be associated with specific microbial populations
Performance of outbreak management plans for emerging plant diseases: the case of almond leaf scorch caused by Xylella fastidiosa in mainland Spain
Full text linkOutbreak response to quarantine pathogens and pests in the European Union (EU) is regulated by the EU Plant Health Law, but the performance of outbreak management plans in terms of their effectiveness and efficiency has been quantified only to a limited extent. As a case study, the disease dynamics of almond leaf scorch, caused by Xylella fastidiosa (Xf), in the affected area of Alicante, Spain, were approximated using an individual-based spatial epidemiological model. The emergence of this outbreak was dated based on phylogenetic studies, and official surveys were used to delimit the current extent of the disease. Different survey strategies and disease control measures were compared to determine their effectiveness and efficiency for outbreak management in relation to a baseline scenario without interventions. One-step and two-step survey approaches were compared with different confidence levels, buffer zone sizes and eradication radii, including those set by the EU legislation for Xf. The effect of disease control interventions was also considered by decreasing the transmission rate in the buffer zone. All outbreak management plans reduced the number of infected trees (effectiveness) but large differences were observed in the number of susceptible trees not eradicated (efficiency). The two-step survey approach and high confidence level increased the efficiency, while also reducing the transmission rate. Only the outbreak management plans with the two-step survey approach removed infected trees completely, but they required greater survey efforts. Although control measures reduced disease spread, surveillance was the key factor in the effectiveness and efficiency of the outbreak management plans
Phenotypic and Gene Expression Analysis of Fruit Development of ‘Rojo Brillante’ and ‘Fuyu’ Persimmon (Diospyros kaki L.) Cultivars in Two Different Locations
Full text linkFruit development and maturation rely on intrinsic genetic programs involving hormone
biosynthesis and signalling and environmental cues, integrating phenological cycles and climatic
issues encompassing abiotic stresses and climate change. In persimmon trees, environmental inputs
strongly influence fitness and agricultural performance, and fruit yield can be severely compromised
by them. We have grown two persimmon accessions (‘Rojo Brillante’ and ‘Fuyu’) under contrasting
meteorological conditions of two locations in Spain and Japan. Fruit size, colour change, and firmness
parameters were followed during fruit development from 30 days after fruit set until commercial
ripening, and the expression of genes related to ethylene production and signalling, gibberellin
response, carotenoid biosynthesis, cell wall dynamics, and oxidative stress were reported. Genes
depending on intrinsic developmental programs (ethylene and ripening variables, mostly) showed
common expression trends in both cultivars and locations, whereas gibberellin and abiotic stressrelated
genes mimicked reduced fruit growth and abiotic stress associated with higher summer
temperatures (>35 ◦C) and lower rainfall reported in the Spanish location. The expression pattern
of these genes is consistent with a growth–defence trade-off that explains fruit differential growth
through hormonal and stress tolerance mechanisms
Incorporación de eugenol en recubrimientos a base de proteína de suero lácteo y proteína de soja para el control de las podredumbres azul y amarga en mandarina
Full text linkLas podredumbres azul, causada por Penicillium italicum, y ácida o amarga, causada por Geotrichum citri-aurantii, pueden generar importantes pérdidas económicas en poscosecha de cítricos. Su control convencional mediante la aplicación repetida de fungicidas químicos de síntesis conlleva problemas sanitarios y medioambientales. Por lo tanto, el objetivo de este trabajo fue la búsqueda de alternativas naturales y no contaminantes para el control de estas enfermedades de poscosecha en mandarinas. Para ello, se estudió la actividad antifúngica in vitro de los aceites esenciales de citronela (lemongrass, LG) y canela (CN), el
eraniol (GE), el eugenol (EU) y el extracto de ajedrea (Satureja montana, SM) a diferentes concentraciones contra P. italicum y G. citriaurantii. De todos ellos, el EU fue el que mayor actividad antifúngica mostró in vitro a una menor concentración para ambos hongos, por lo que se seleccionó como ingrediente activo antifúngico de recubrimientos comestibles (RCs) formulados con proteína del suero lácteo (WPI) y con proteína de soja (SP). Estas proteínas se mezclaron con diferentes cantidades de glicerol, ácido oleico y cera carnauba para obtener diferentes RCs compuestos a los que se añadió un 2% de EU. Los RCs se aplicaron en ensayos in vivo con mandarinas “Tango” inoculadas 24 h antes con P. italicum y G. citri aurantii. La incidencia de la
enfermedad (%) y la severidad (diámetro de la lesión, mm) se midieron durante 14-20 días de incubación a 20 °C. El RC de SP fue el más eficaz, con reducciones de la incidencia de la podredumbre azul del 40% tras 5 días de almacenamiento a 20 °C, mientras que el RC de WPI redujo la incidencia en un 20-30% respecto al control sin recubrir. Además, el RC de SP también redujo la incidencia de la podredumbre ácida en un 35% tras 12 días de incubación a 20 ºC. Estos resultados pueden contribuir al
desarrollo de nuevos RCs comerciales antifúngicos seguros para el control integrado de las principales enfermedades de
poscosecha de cítricos
Natural pectin-based edible composite coatings with antifungal properties to control green mold and reduce losses of ‘Valencia’ oranges
Full text linkNovel pectin-based, antifungal, edible coatings (ECs) were formulated by the addition of
natural extracts or essential oils (EOs), and their ability to control green mold (GM), caused by
Penicillium digitatum, and preserve postharvest quality of ‘Valencia’ oranges was evaluated.
Satureja montana, Cinnamomum zeylanicum (CN), Commiphora myrrha (MY) EOs, eugenol
(EU), geraniol (GE), vanillin, and propolis extract were selected as the most effective
antifungal agents against P. digitatum in in vitro assays. Pectin-beeswax edible coatings
amended with these antifungals were applied to artificially inoculated oranges to evaluate GM
control. ECs containing GE (2 g/kg), EU (4 and 8 g/kg), and MY EO (15 g/kg) reduced disease
incidence by up to 58% after 8 days of incubation at 20 °C, while CN (8 g/kg) effectively
reduced disease severity. Moreover, ECs formulated with EU (8 g/kg) and GE (2 g/kg) were
the most effective on artificially inoculated cold-stored oranges, with GM incidence reductions
of 56 and 48% after 4 weeks at 5 °C. Furthermore, ECs containing EU and MY reduced weight
loss and maintained sensory and physicochemical quality after 8 weeks at 5 °C followed by 7
days at 20 °C. Overall, ECs with EU were the most promising and could be a good natural,
safe, and eco-friendly commercial treatment for preserving orange postharvest quality