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Capability of hyperspectral and thermal data to predict gas exchange and chlorophyll fluorescence parameters in broccoli
No full textThe spatial determination of crop water status (CWS) requires the establishment of robust relationships between direct and indirect measurements. The objective of this study was to explore the potentialities of visible-near infrared (VIS-NIR) hyperspectral and thermal (TIR) data to predict gas exchange and chlorophyll fluorescence parameters in a broccoli (‘Brassica oleracea’ cv. ‘Ulysses’) cultivation. For this purpose, six field campaigns were carried during the growing season 2023. The obtained relationships evidence the better accuracies in predicting gas exchange and chlorophyll fluorescence parameters by using the TIR domain in comparison to the use of VIS-NIR hyperspectral data (absolute correlation coefficients of 0.62-0.81 and 0.51-0.67, respectively). The relationships obtained for chlorophyll fluorescence parameters were more accurate than those relationships obtained for gas exchange parameters, independently on the use of TIR or VIS-NIR hyperspectral data. These results suggest that other co-variables should be included in order to improve the obtained relationships (i.e. combination of VIS-NIR and TIR domain, agrometeorological data and soil water content). The identification of the most appropriate methodology for deriving CWS will allow transferring the knowledge acquired in this study to sensors on board proximal/remote platforms (e.g., unmanned aerial vehicles and/or satellites) with the ultimate goal of obtaining spatially distributed CWS estimates
Algoritmo para la programación automática del riego en cítricos mediante variables suelo-atmósfera
Get PDFEl sector dispone de una amplia gama de dispositivos para la programación del riego, pero la interpretación de la información puede ser una tarea compleja. El éxito de las nuevas tecnologías reside en el desarrollo de programadores con capacidad de interpretación automatizada de la información. El objetivo de este trabajo ha sido evaluar el uso de nuevos algoritmos de cálculo (Modelo) para programación del riego en una parcela comercial de cítricos. La metodología propone una programación del riego para una semana concreta (NRs) mediante corrección de la programación de la semana previa (NRs-1) mediante dos coeficientes. Por un lado, un coeficiente basado en la información de sondas de humedad del suelo (kƟ) y, por otro lado, un coeficiente basado en la estimación de la evapotranspiración de referencia (ET0) según Hargreaves-Samani (kETo) a partir de dos fuentes: i) los registros históricos del Sistema de Información Agroclimática para el Regadío (Red SiAR); y, ii) la integración de previsiones meteorológicas proporcionadas por la AEMET. El procedimiento de programación del riego descrito se ha validado en la campaña 2022-23 en una parcela comercial de naranjo Valencia cv. ‘Midknight’ en Pedralba (Valencia). Los tratamientos de riego aplicados fueron: i) Control, regado considerando el 100% ETc ajustado por un técnico; ii) Modelo kƟ+kETo-hist (ModeloH) y, iii) Modelo kƟ+kETo-prev (ModeloP). Los modelos se aplicaron a partir del 23 de mayo de 2022 (semana 21 de 2022) hasta recolección, el 11 de abril de 2023 (semana 15 de 2023). En la aplicación de los nuevos modelos, el coeficiente derivado de la humedad del suelo (kƟ) presentó un comportamiento similar. Sin embargo, kETo mostró un comportamiento diferencial. En el ModeloH, el kETo-hist reflejó de manera más precisa las variaciones en la ETo semanal acumulada, mientras que el ModeloP, el kETo-prev generó una infraestimación de este parámetro, motivado por la propia metodología asociada a su cálculo. De este modo, las dosis de riego aplicadas fueron de 443 mm para el Control, 466 mm para el ModeloH (+7,6% Control) y 305 mm en el ModeloP (-31 % Control). La menor dosis de riego derivada de la aplicación del ModeloP, ocasionó durante las etapas de crecimiento del fruto un descenso importante de la humedad en el suelo. El estrés hídrico sufrido tuvo un impacto negativo sobre el rendimiento, debido a un menor peso del fruto. En el caso del ModeloH, las estimaciones se ajustaron mucho más a la programación del riego del tratamiento Contro
Recent Development in the Preharvest 1-MCP Application to Improve Postharvest Fruit Quality
Get PDF1-Methylcyclopropene (1-MCP), an ethylene action inhibitor, is routinely applied
to fruit as a postharvest treatment prior to cold storage to extend fruit storability and
posterior shelf life. Nevertheless, preharvest 1-MCP applied as a liquid spray to trees
is a novel treatment for maintaining fruit quality throughout the postharvest in some
crops and can be a very useful tool for improving handling operations in packing
houses. This chapter aims to provide an overview of not only employing 1-MCP as
a preharvest treatment in different crops, but also of its effect on the biochemical
and physico-chemical parameters that influence fruit postharvest quality, storage
capacity, and chilling injury development. It also intends to address the main factors
related to the preharvest 1-MCP application effect, such as application time, optimum
concentrations, and its combination with other preharvest treatments
Estimación de los niveles nutricionales de hojas de cítricos mediante análisis no destructivo aplicando técnicas de aprendizaje automático
Get PDFOne of the characteristics of all living beings is that adequate nutrition has a positive
impact on health. In the case of plants, and specifically in fruit trees, adequate nutrition is also
essential for them to grow healthy and produce fruits in the highest quantity and quality
possible. Therefore, optimal nutrition is key for any farmer. However, excessive use of fertilisers
can harm the environment and be a waste of resources for farmers. One of the keys to achieving
adequate fertilisation is an accurate diagnosis of the nutritional status of the tree. Traditionally,
this diagnosis is made by destructive ionomics analysis, which represents a high economic cost
and a delay in obtaining the results. This work proposes Vis-NIR hyperspectral imaging and
machine learning regression models to estimate the concentrations of macronutrients (N, P, K,
and Ca) and micronutrients (Mn and Fe) in citrus leaves. The methodology involved the
application of several machine learning regression methods (linear regression, partial least
squares, random forest, support vector regression, and Ada Boost). Data were normalised with
standard normal variable (SNV), and principal component analysis (PCA) was used to reduce
dimensionality. The results were promising in estimating nutrients with R2 greater than 0,50 in
all cases, especially nitrogen (R2 of 0.77)
Postharvest Application of Novel Bio-Based Antifungal Composite Edible Coatings to Reduce Sour Rot and Quality Losses of ‘Valencia’ Oranges
Get PDFSour rot, caused by Geotrichum citri-aurantii, can produce significant postharvest losses of citrus fruits and, currently, cannot be effectively controlled by the postharvest fungicides registered in EU countries. Therefore, novel antifungal edible coatings (ECs) based on citrus pectin and beeswax and enriched with eugenol (EG), geraniol (GR), propolis extract (PR) or essential oils (EOs) from Satureja montana (SA), Cinnamomum zeylanicum (CI), or Commiphora myrrha (CM), were developed as alternatives to reduce sour rot and preserve the postharvest quality of ‘Valencia’ oranges. These natural agents were incorporated into the EC formulation and then applied to inoculated oranges. ECs enriched with EG (2–8 g/kg), GR (4 and 8 g/kg), PR (5–20 g/kg), and CM EO (15 g/kg) reduced disease incidence and severity by 75 to 100% compared to uncoated oranges after 20 days of incubation at 20 °C. ECs containing EG (8 g/kg), GR (4 g/kg), and PR (20 g/kg) reduced weight loss and retained firmness of oranges after 14 days of shelf life at 20 °C. Furthermore, all tested ECs maintained the fruit’s sensory and physicochemical quality. Overall, the EG-enriched pectin EC performed best, showing potential as a safe, bio-based alternative to conventional waxes containing synthetic fungicides for the management of citrus postharvest sour rot
Study of light penetration depth of a Vis-NIR hyperspectral imaging system for the assessment of fruit quality. A case study in persimmon fruit
No full textHyperspectral imaging (HSI) is one of the most studied optical techniques to estimate the internal quality of fruits and vegetables. Absorbance and reflectance of the light radiation are specific to each biological tissue and are directly related to its chemical composition and physical characteristics. These properties are influenced by other extrinsic factors, such as the instrumentation or the light source, which can reduce the reproducibility of the experiments. Determining the actual depth of light penetration into tissue could help validate non-contact methods as accurate tools to assess quality properties based on optical properties. In the case of HSI systems, it is crucial to know how far the light penetrates at each wavelength. A non-destructive approach, based on the spatially resolved spectroscopic principle, was proposed to estimate the light penetration depth of a HSI system in a Vis-NIR configuration (in the range 450–1050 nm). This method was applied to measure the light penetration depth in persimmon fruit. The absorption (μa) and scattering (μ's) coefficients from Farrell's diffusion theory were estimated using the backscattered light measured at different distances from the incident point light at each wavelength in hyperspectral images of persimmon fruit. The actual light penetration depth was obtained by measuring the reflectance of cut pieces of persimmon fruit with different thicknesses. Linear regression was used to relate the depth of penetrability obtained by both protocols, the estimated or non-destructive protocol and the actual or destructive protocol, showing a high relationship (R2 > 0.8 and RPD>2.5) in the range 610–1050 nm. This confirms that this non-destructive approach proposed for estimating the light penetration depth of a Vis-NIR HSI system in persimmon fruit is accurate, so it could be used as a valuable method to evaluate other HSI systems for different fruits
Effect of providing citrus pulp‑integrated diet on fecal microbiota and serum and fecal metabolome shifts in crossbred pigs
Get PDFThe study aimed to assess the impact of dehydrated citrus pulp (DCP) on growth performance, fecal characteristics, fecal bacterial composition (based on 16S rRNA analysis), and fecal and serum metabolomic profiles in crossbred pigs. 80 finishing pigs Duroc × (Landrace × Large White) were fed either a control diet (C) or a diet with 240 g/kg DCP (T) for six weeks. Including DCP in diets tended to decrease feed intake, increased (p < 0.05) the concentrations of acetic and heptanoic acids and decreased (p < 0.05) fecal butyric and branched-chain fatty acid concentrations in feces. Animals fed DCP exhibited a lower abundance of the genera Clostridium and Romboutsia, while Lachnospira significantly increased. Orthogonal partial least squares discriminant analysis plotted a clear separation of fecal and serum metabolites between groups. The main discriminant fecal metabolites were associated with bacterial protein fermentation and were downregulated in T-fed pigs. In serum, DCP supplementation upregulated metabolites related to protein and fatty acids metabolism. In conclusion, the addition of DCP as an environmentally friendly source of nutrients in pig diets, resulted in modifications of fecal bacterial composition, fermentation patterns, and overall pig metabolism, suggesting improvements in protein metabolism and gut health
Effect of olive cake in growing pig diets on fecal microbiota fermentation and composition
Get PDFThe intestinal microbiota plays a critical role in the metabolism and health of the host. The present study investigated the impact of two types of olive cake on short-chain fatty acid (SCFA) concentrations and the faecal microbiota composition of pigs. A total of 30 pigs (Landrace x Large white) with an initial body weight (BW) of 47.9±4.21 kg were divided into three groups according to the feed they received: control feed (C), feed with 200g/kg of partially defatted olive cake (PDOC) or feed with 200g/ kg of cyclone olive cake (COC). Faecal samples were collected from each animal after 3 weeks of the feeding trial
Recent research accomplishments on early detection of Xylella fastidiosa outbreaks in the Mediterranean Basin
Get PDFXylella fastidiosa is a major transboundary plant pest, causing severe socioeconomic impacts. Development of preventive strategies and methods for surveillance, early detection, monitoring, and accurate diagnosis of X. fastidiosa and its vectors, are keys to preventing the effects of this plant pathogen, and assist timely eradication or optimisation of containment measures. This review focuses on approaches for early detection of X. fastidiosa in the Mediterranean Basin, including development of climatic suitability risk maps to determine areas of potential establishment, and epidemiological models to assist in outbreak management through optimized surveillance and targeted responses. The usefulness of airborne hyperspectral and thermal images from remote sensing to discriminate X. fastidiosa infections from other biotic- and abiotic-induced spectral signatures is also discussed. The most commonly used methods for identifying X. fastidiosa in infected plants and vectors, and the molecular approaches available to genetically characterize X. fastidiosa strains, are described. Each of these approaches has trade-offs, but stepwise or simultaneous combinations of these methods may help to contain X. fastidiosa epidemics in the Mediterranean Basin
Combining Genetic and Transcriptomic Approaches to Identify Transporter-Coding Genes as Likely Responsible for a Repeatable Salt Tolerance QTL in Citrus
Get PDFThe excessive accumulation of chloride (Cl−) in leaves due to salinity is frequently related to decreased yield in citrus. Two salt tolerance experiments to detect quantitative trait loci (QTLs) for leaf concentrations of Cl−, Na+, and other traits using the same reference progeny derived from the salt-tolerant Cleopatra mandarin (Citrus reshni) and the disease-resistant donor Poncirus trifoliata were performed with the aim to identify repeatable QTLs that regulate leaf Cl− (and/or Na+) exclusion across independent experiments in citrus, as well as potential candidate genes involved. A repeatable QTL controlling leaf Cl− was detected in chromosome 6 (LCl-6), where 23 potential candidate genes coding for transporters were identified using the C. clementina genome as reference. Transcriptomic analysis revealed two important candidate genes coding for a member of the nitrate transporter 1/peptide transporter family (NPF5.9) and a major facilitator superfamily (MFS) protein. Cell wall biosynthesis- and secondary metabolism-related processes appeared to play a significant role in differential gene expression in LCl-6. Six likely gene candidates were mapped in LCl-6, showing conserved synteny in C. reshni. In conclusion, markers to select beneficial Cleopatra mandarin alleles of likely candidate genes in LCl-6 to improve salt tolerance in citrus rootstock breeding programs are provided