Scientia Agropecuaria

Diversity of arbuscular mycorrhizal fungi and Soil Physicochemical Parameters in Forest Species of the Abras de Mantequilla Wetland, Ecuador

Abstract Wetlands worldwide face increasing challenges due to human activities such as water extraction, deforestation, and overfishing. These ecosystems are crucial for biodiversity, water retention, and purification. In Ecuador, the “Abras de Mantequilla” wetland exemplifies these pressures. It serves as a vital site for studying the interactions between soil fertility and arbuscular mycorrhizal fungi (AMF) in forest ecosystems. The study focused on the soil fertility, particularly in relation to AMF in "Noah Morán" secondary forest within the Abras de Mantequilla wetland. The key role of AMF in improving soil fertility was highlighted. Soil samples were collected from the root zone of four forest tree species i.e., Guazuma ulmifolia, Albizia guachapele, Eugenia pustulescens, Cecropia peltate. The four investigated soil samples had marginal differences in the soil physicochemical properties. Number of AMF species were found in the four soils in the range of 16 to 39; Number of por Several AMF lowest por the lowest (16) and highest (39) AMF species were found in E. pustulescens and A. guachapele soils, respectively. AMF species ‘Akent’ was the most dominant (abundance #16) AMF species found in the soils of C. peltate. The ranges of Shannon_H and Simpson_1-D values were found to be 1.78-1.9 and 0.79-0.85, respectively. These insights are important to understanding soil-plant-microorganism interactions in promoting sustainable agricultural practices in the Abras de Mantequilla wetland.

Biodegradable trays made from Poraqueiba serícea Tulasne seed starch and Zea Mays cob flour

Abstract The environmental impact of polystyrene and other petrochemical packaging has increased interest in researching biodegradable materials as alternatives. The main objective of this research was to develop biodegradable trays from five formulations of Poraqueiba sericea Tulasne (known as umari) seed starch and corn cob meal. The trays were produced using the thermoforming process applying temperatures of 135°C and 145°C for each side of the tray for a time of 6.5 min. Physical analysis of the trays showed that the increase in the percentage of corn cob flour caused changes in color (L*: 68.69 - 64.94), thickness (2.20 - 3.17 mm), density (0.251 - 0.414 g/cm3), moisture (3.85 - 5.68%), water absorption (21.86 - 39.05%), volatile solids (95.33 - 98.31%). Regarding mechanical properties, it was also evidenced the increase in hardness (67.70 - 90.97 N), fracturability (1.43 and 3.19 mm), tension (2.84 to 3.43 MPa) and elongation (1.54 to 2.04%). The formulation of 87.5% umari seed starch and 12.5% tusa flour presented more favorable physical and mechanical properties. Further analysis of this formulation was performed by Fourier transform infrared spectroscopy (FTIR), which identified bands characteristic of starch (1055 and 1027 cm-1); X-ray diffraction (XRD), which revealed characteristic peaks (2θ = 16.83° and 2θ = 22.69°) associated with cellulose crystallinity in the biodegradable tray; and scanning electron microscopy (SEM), which revealed cellulosic voids with irregular distribution due to the addition of fibers. Future research should examine the potential applications of these biodegradable trays for the packaging of raw materials in the food industry.

La floricultura como cultivo alternativo: Análisis descriptivo, modelación con inteligencia artificial, análisis de escenarios y análisis económico

Resumen La floricultura es un sector de creciente importancia a nivel mundial, contribuyendo a la generación de empleo, ingresos y a la promoción de la biodiversidad y la sostenibilidad. Este estudio tuvo como objetivo identificar los factores que influyen en la adopción de la floricultura como cultivo alternativo en la provincia de Leoncio Prado, Perú, y evaluar su viabilidad económica. Para ello, se encuestó a 269 agricultores, analizando actitudes, aptitud de la tierra, factores socioeconómicos y ambientales. Mediante análisis descriptivo, pruebas de chi-cuadrado y regresión logística (p < 0,1) se seleccionaron los factores influyentes. Además, se emplearon múltiples algoritmos de aprendizaje automático (Árboles de Decisión, Regresión Logística, KNN, SVM, Ensemble, Redes Neuronales, Naive Bayes) con validación cruzada (k = 5) y métricas AUC para modelar la intención de adopción. Se desarrollaron escenarios incrementando la predisposición a adoptar la floricultura, y se realizó un análisis económico de ocho especies tropicales (Ginger Rojo, Anturio, Bastón del Emperador, Heliconia, Gardenia, Pico de Loro, Heliconias Golden, Maracas). Los resultados revelan que la disposición a cambiar de cultivo, la participación en campañas de sensibilización, la destinación de áreas a la conservación y el control de costos son factores clave. El modelo de redes neuronales alcanzó un AUC de 83,3% y escenarios mejorados indican que la adopción podría incrementar hasta en 11,32%. El Ginger Rojo demostró alta rentabilidad (VAN S/10428; TIR 51%; PRI 0,7 años). En conclusión, la floricultura representa una alternativa económica y ambientalmente viable que contribuye a la diversificación agrícola y a la sostenibilidad.

Abstract Floriculture is a sector of growing global importance, contributing to employment generation, income creation, and the promotion of biodiversity and sustainability. This study aimed to identify the factors influencing the adoption of floriculture as an alternative crop in the province of Leoncio Prado, Peru, and to assess its economic viability. A total of 269 farmers were surveyed, analyzing attitudes, land suitability, and socioeconomic and environmental factors. Influential factors were identified using descriptive analysis, chi-square tests, and logistic regression (p < 0.1). Additionally, multiple machine learning algorithms (Decision Trees, Logistic Regression, KNN, SVM, Ensemble, Neural Networks, Naive Bayes) with cross-validation (k = 5) and AUC metrics were employed to model adoption intentions. Scenarios were developed to increase the willingness to adopt floriculture, and an economic analysis of eight tropical species (Red Ginger, Anthurium, Emperor's Staff, Heliconia, Gardenia, Parrot's Beak, Golden Heliconias, Maracas) was conducted. The results reveal that willingness to change crops, participation in awareness campaigns, allocation of areas for conservation, and cost control are key factors. The neural network model achieved an AUC of 83.3%, and improved scenarios indicate that adoption could increase by up to 11.32%. Red Ginger demonstrated high profitability (NPV S/10428; IRR 51%; PBP 0.7 years). In conclusion, floriculture represents an economically and environmentally viable alternative that contributes to agricultural diversification and sustainability.

Biochemical and enzymatic alterations of watermelon associated with irrigation management and inoculation with Rhizobacteria

Abstract Water stress has caused major losses in the agricultural productivity of crops, inducing the search for alternatives for sustainable cultivation. In this context, the objective of this study was to evaluate the tolerance of watermelon under water stress, inoculated with bacterial strains of the genus Bacillus spp., regarding the biochemical and enzymatic variables in the flowering stage. A randomized block design was adopted in a split-plot 4x4 factorial scheme, with plots consisting of four levels of soil water availability (40%, 60%, 80% and 100% of field capacity - FC) and subplots consisting of four inoculations (Negative Control (NC); XX6.9 bacteria; P6.2 bacteria; MIX - co-inoculation of XX6.9 and P6.2 bacteria), with five replicates. XX6.9 bacteria and NC were the treatments most affected by severe water stress, since at the soil water availability (SWA) level of 40% FC they showed high contents of the oxidative marker (MDA) and proline. Although the inoculation with XX6.9 bacteria promoted a higher content of osmoregulators such as proteins, total soluble sugars and reducing sugars, it was not enough to attenuate the effects of water deficit. On the other hand, treatments with P6.2 bacteria and MIX of bacteria showed reduced levels of MDA at the SWA level of 40% FC, accompanied by high enzymatic activity of POD and CAT, which may contribute to the tolerance of the watermelon crop to water stress.

Sapote gum as a new biopolymer suitable emulsion stabilizer: Grapeseed oil ultrasonic emulsification

Abstract Sapote gum (SG) is a new biopolymer with promissory functional properties. This study aimed to determine if SG is a suitable emulsifier for obtaining stable grape seed oil (GSO) emulsions. In the first stage, coarse emulsion concentrations of SG and grapeseed oil - GSO were evaluated, applying the Central Composite Rotational Design (0.59% to 3.41% of SG and 12.93% to 27.07% GSO). For the second stage, using a Centered Face Design - CFD, the resulting emulsion was sonicated at 90, 270, and 450 Watts at 5, 10, and 15 min. Finally, a validation was made. Emulsions were evaluated through microstructure, droplet size, kinetic stability, heat stress, and rheology. Micrographs of the first-stage emulsions showed droplets up to 3.8 μm diameter and a creaming index between 0.00% and 28.39% after 24 h. Optimization indicates that the higher the concentration of gum (3.5%) and GSO (25%), the more kinetically stable emulsions are produced. Ultrasonic emulsions showed no significant difference in droplet size and kinetic stability before 14 days of rest. Ultrasonic validation was made at 450 W for 6 min, resulting in emulsions stable for 20 days and with rheological characteristics interesting for food or cosmetic industries.

Estimation of nitrogen content in sugarcane based on vegetation indices derived from Sentinel-2 data

Resumo A cana-de-açúcar ocupa grande escala territorial no mundo e busca constantemente por mecanismos para monitorar os nutrientes no ciclo de produção da cultura, utilizando métodos não destrutivos. O estudo com objetivo estimar o teor de nitrogênio na folha da cana-de-açúcar foi desenvolvido na safra 2021/2022 sobre dois talhões comerciais de sequeiro cultivares (RB867515 = 50,75 ha) e (CVSP7870 = 48,56 ha) na Usina Energética Serranópolis-Goiás, avaliando a eficiência dos índices bioquímicos de vegetação Fraction of Absorbed Photosynthetically Active Radiation (fAPAR) e Canopy Chlorophyll Content (CCC) processados utilizando modelo de transferência de radiação RTM PROSAIL, comparados aos índices Normalized Difference Vegetation Index (NDVI) e Green Normalized Difference Vegetation Index (GNDVI), processados utilizando modelos matemáticos e razão de bandas. Ambos, baseados em série temporal de dados Sentinel-2 como variáveis de entrada. A validação do Agro-Modelo ocorreu através de análise de tecido foliar coletada em sete avaliações intercaladas durante o período de permanência da cultura no campo. Foi evidenciado a funcionalidade dos quatro índices, destacando o índice bioquímico fAPAR sob a ótica da estatística descritiva (R² = 0,970 e RMSE = 0,46) para o cultivar RB867515 e (R² = 0,940 e RMSE = 0,69) para o cultivar CVSP7870.

Abstract Sugarcane occupies a large territorial scale in the world and is constantly searching for mechanisms to monitor nutrients in the crop production cycle, using non-destructive methods. The study aimed to estimate the nitrogen content in the sugarcane leaf was developed in the 2021/2022 harvest on two commercial fields of dryland cultivars (RB867515 = 50.75 ha) and (CVSP7870 = 48.56 ha) at the Serranópolis-Goiás mill, evaluating the efficiency of the biochemical vegetation indices Fraction of Absorbed Photosynthetically Active Radiation (fAPAR) and Canopy Chlorophyll Content (CCC) processed using the radiation transfer model RTM PROSAIL, compared to the Normalized Difference Vegetation Index (NDVI) and Green Normalized Difference Vegetation Index (GNDVI), processed using mathematical band ratio models. Both were based on a time series of Sentinel-2 data as input variables. The validation of the Agro-Model occurred through analysis of leaf tissue collected in seven interspersed evaluations during the period the crop remained in the field. The functionality of the four indexes was evidenced, highlighting the biochemical index fAPAR from the perspective of descriptive statistics (R² = 0.970 and RMSE = 0.46) for the cultivar RB867515 and (R² = 0.940 and RMSE = 0.69) for the cultivar CVSP7870.

Synthesis, characterization and biological activity of the Cu (II)-1,3-PDTA [(Cu (II) (PDTA)] complex for the control of Erwinia chrysanthemi (soft rot) in the parsley manioc (Arracacia xanthorrhiza Bancroft)

Abstract Synthesis, characterization and biological activity of the Cu(II)-1,3-PDTA complex was performed by two synthetic routes: sodium and carbonate pathways. The Cu (II)-1,3-PDTA complex can be easily produced by the 1,3-PDTA binder, commercially available as Trilon F (BASF) which is available as sodium or acid salt for the coordination of Cu (II). The biological activity of the Cu (II)-1,3-PDTA [Cu (II)-PDTA] complex was performed to analyze the activity against the bacterium Erwinia chrysanthemi Bancroft. The bacterium is the causative agent of soft rot in the parsley maniac (Arracacia xanthorrhiza Bancroft). The bacterium was isolated from parsley manioc infected with soft rot. The metal complex sensitivity tests were performed by diffusion antibiogram. The mean values of the halos and standard deviations of the zones of inhibition were obtained for the [Cu (II) (PDTA)] and Streptomycin complexes. The concentrations of the complexes evaluated were 10-3, 10-2 and 10-1 M (equivalent to 36.3 g L-1 (3.63%), 3.63 g L-1 (0.363%) and 0.363 g L-1 (0.0363%), respectively). The halos were 25.0 ± 1.2 mm for control. For [Cu (II) (PDTA)] complexes, the obtained values were 9.5 ± 0.6, 15.0 ± 0.8 and 24.0 ± 0.8 via sodium and 12.0 ± 1.6, 25.0 ± 0.8 and 31.0 ± 1.9 via carbonate, for 10-3, 10-2 and 10-1 M, respectively. The results showed that the bactericidal activity of the Cu (II)-1,3-PDTA complex obtained by the two synthetic routes are adequate for the control of Erwinia chrysanthemi Bancroft.

Pleurotus spp: A cosmopolitan fungi of biotechnological importance

Abstract The genus Pleurotus presents a multivariate species diversity due to its ability to grow in different substrates and environments. Whether wild or cultivated, they are edible mushrooms, as they present a high nutritional value and are medicinal due to their bioactive compounds with positive health effects. The aim of this review is to highlight the importance of the genus Pleurotus, since it is a cosmopolitan mushroom, and its properties can be used in different industrial applications and be a functional alternative for our future. Due to their saprophytic nature, they produce enzymes that act on the substrate in which they grow, degrading lignocellulosic material such as wood, forest and agricultural residues, hardwoods, wood by-products, cereal straw, bagasse, etc., and thanks to this degradative capacity, their enzymes are used in a wide range of biotechnological and environmental applications. In order to increase their production and consumption not only for their nutritional qualities, but also for their nutraceutical and biotechnological qualities, ease of cultivation, low investment cost, etc., new ways are being sought to increase their performance in cultivation. Recently, research has expanded the search for alternative uses of the Pleurotus genus, which has led to an increase in its cultivation, as well as its application in different fields of biotechnology. The cultivation of Pleurotus mushrooms represents an opportunity to generate a sustainable process and incorporate the process into a circular economy, generating environmental, social and economic benefits. The use of agro-industrial substrates and the subsequent reuse of the spent substrate as compost or organic fertilizer reduces the amount of waste that ends up in landfills and minimizes methane production. This allows for a more sustainable and environmentally friendly production model. Therefore, it is necessary to develop strategies for the promotion, marketing and sustainable production of products derived from these fungi.

Advances in the use of active yeast in raising chickens

Abstract The broiler industry supplies quality protein, which is in constant development. It seeks productive strategies that improve production, health, growth, and survival and reduce the poultry industry's diseases, stress, and long-term environmental impact. Broiler chickens are exposed to numerous microorganisms that alter production, and this is an opportunity for yeasts to promote the growth of organisms, stimulate the immune system, improve health, promote changes in intestinal structure, and inhibit pathogens. This review summarizes the current knowledge and effect of active yeast species on raising chickens, nutrition, immunity, digestibility, changes in intestinal structure, and pathogens on those organisms. Due to their nutritional value, active yeasts are used as natural and alternative ingredients in broiler chickens. They are a source of b-glucans, chitin, nucleic acids, mannan-oligosaccharides, b-carotene, and vitamins. Enzymes they produce improve intestinal maturity and digestion. The immune and antioxidant properties of yeasts play an essential role as probiotics and immunostimulants to enhance the resistance of broilers against common viral and bacterial diseases. Bioactive products generated by active yeasts can improve intestinal microbiota and positively alter the immune response, phagocytosis, encapsulation, etc. Different active yeast species and strains have been used and have generated exciting results. They are popular as beneficial candidates for nutrition by maintaining broiler chickens’ health's and well-being conditions. Future studies must understand the functioning and effect of species and strains on broiler chickens in their different processes, the use of new research tools (proteomics, radioisotopes, real-time molecular biology, etc.) can facilitate these studies.

Phytophthora species causing root rot in avocado seedlings at Colombian nurseries: Morphological, molecular, and pathogenic analysis

Abstract Expansion of avocado production areas in Colombia has led to an increased demand for plant propagation material. However, this expansion has exacerbated phytosanitary challenges, particularly root rot disease mainly associated with Phytophthora spp. Therefore, this study aimed to identify Phytophthora species associated with root rot in avocado seedlings within nurseries. Avocado plants exhibiting wilting symptoms were collected from nurseries in the departments of Quindío, Risaralda, and Valle del Cauca (Colombia). Segments of diseased roots were selected, cut, and surface-disinfected, before being planted on Potato Dextrose Agar (PDA) supplemented with antibiotics and fungicides. Microorganism identification was conducted using taxonomic keys and confirmed by molecular techniques employing the identification based on phylogenetic hypothesis, using ITS1-5.8s-ITS2 region encoding for rRNA. Isolates obtained from necrotic avocado roots were identified as P. cinnamomi and P. heveae. The pathogenicity of the isolates was confirmed in avocado seedlings through inoculation, resulting in symptom reproduction. Consequently, this study identified P. cinnamomi and P. heveae as causal agents of root rot in avocado during the nursery stage.

Rice leaf disease detection using the Stretched Neighborhood Effect Color to Grayscale method and Machine Learning

Abstract The emergence of Machine Learning (ML) technologies and their integration into agriculture has demonstrated a significant impact on disease detection in crops, enabling continuous monitoring and enhancing risk planning and management. This study applied image processing techniques such as thresholding, gamma correction, and the Stretched Neighborhood Effect Color to Grayscale (SNECG) method, alongside ML, to develop a predictive model for identifying five types of rice diseases. The ML techniques used included Logistic Regression, Multilayer Perceptron, Support Vector Machines, Decision Trees, and Random Forests (RF). Hyperparameters were optimized and evaluated through 5-fold cross-validation. In the results, the SNECG method successfully converted images to grayscale, capturing essential features of lesions on rice leaves. The ML models developed with these techniques showed evaluation metrics exceeding 80%, with the RF model (precision = 88.31%) demonstrating superior performance. Additionally, the RF model was integrated into an interface designed for agricultural decision-making. The practical application of the developed model could significantly improve the ability to detect and manage diseases in rice crops.