Scientia Agropecuaria

Long-Term impact of rice cultivation on soil quality indicators in Northern Amazonia Savanna

2025-02-19T01:36:03+00:00

Changes in soil attributes following changes in management strategies in rice cultivation can alter soil quality, either positively or negatively. The aim of this study was to evaluate soil quality indicators, based on physical, chemical and microbiological soil attributes in Amazonian savanna under rice cultivation with different ages. The research was conducted in five areas under continuous rice cultivation during 1, 3, 8, 13, and 25 years, compared with local reference native vegetation. Soil samples were collected at 0-10 cm depth and evaluated for physical attributes such as texture and bulk density, chemical properties such as soil organic carbon, total nitrogen, exchangeable cations, available P, pH, CEC and C/N ratio; and microbiological attributes like microbial biomass carbon, soil microbial respiration, metabolic ratio and microbial coefficient. Acid phosphatase and urease activity were evaluated. With longer periods of time of rice cultivation, soil quality was enhanced with increasing soil fertility, increased soil organic carbon content and enzyme activity. The paddy soil indicators were sensitive to changes in rice cultivation and its duration. Acid phosphatase activity and available phosphorus increased with longer time of rice cultivation, indicating a possible conversion of inorganic into organic phosphorus forms, corroborated by increasing phosphatase activity. Microbiological (SMB-C, SBR, qMIC and qCO₂) and biochemical (urease and acid phosphatase) indicators, as well as soil organic carbon and total nitrogen were highly sensitive to land use changes. Chemical and microbiological indicators are suitable for estimating paddy soil quality in lowland of Amazonian savanna.

Hongos fitopatógenos foliares asociados al cultivo de Prunus persica L.: Identificación morfológica y molecular, y control biológico con Trichoderma asperelloides

2025-02-19T01:50:55+00:00

La presencia de hongos fitopatógenos foliares ocasiona severos daños en hojas y frutos de durazno (Prunus persica L.), en zonas productoras del sur de Chihuahua, México, lo que ha ocasionado una disminución en su producción en un 30%. El objetivo de este trabajo fue identificar morfológica y molecularmente los hongos fitopatógenos foliares asociados al cultivo del duraznero evaluando la patogenicidad en plantas de un año contra Trichoderma asperelloides. Se recolectaron hojas con lesiones color café y marrón en frutos momificados en planta de 19 huertos comerciales de durazno distribuidos en tres municipios de producción regional y nacional en el Estado de Chihuahua México. La identificación de hongos de cuatro aislamientos representativos se realizó utilizando métodos morfológicos. caracterización y análisis filogenético basado en la región espaciadora transcrita interna (ITS1 e ITS4) de ADN ribosomal, parte del factor de elongación de traducción 1-alfa (TEF) un segundo cebador secundario por cada uno de los géneros para, Collectotrichum ACT-512F y ACT-583R, Fusarium con EF1. Para las confrontaciones en planta se inoculo una concentración de 1x10⁶ conidios. mL^-1 de patógenos como de T. asperelloides, evaluando el diámetro y longitud de hoja, altura, severidad e incidencia. Se logró identificar la presencia de Fusarium sambucinum, Collectotrichum gleosporoides y Monilinia frutícola, además la cepa B-F-M1-A2-ACCH-3 de F. Sambucinum obtuvo los valores más altos en la inhibición de las variables de respuesta y en severidad Monilinia frutícola presentó 61,23% como el valor más alto. Se recomienda usar la cepa 3 como control biológico de fitopatógenos foliares.

Multilocus identification and pathogenetic characterization of Colletotrichum endophyte and pathogen species isolated from cocoa leaves and pods (Theobroma cacao) in Ecuador

2024-07-18T16:58:53+00:00

Cacao cultivation is one of the main agricultural products of Ecuador, known internationally for its quality and aroma. However, it is affected by fungal diseases including Moniliophthora roreri, Moniliophthora perniciosa, Phytophthora spp., and Colletotrichum spp. The genus Colletotrichum spp. is known for its characteristics that complicate traditional taxonomic identification. In cacao cultivation, it is one of the most frequently found species as an endophyte of leaves and fruits, yet it is also reported to cause the disease known as anthracnose on leaves and fruits. The objective of this work was to identify at the species level 16 Colletotrichum isolates, 13 from healthy leaf endophytes and 3 from pods with symptoms, through multilocus analysis of the ITS1, 5.8S, and ITS2 region, and partial sequences of the TUB2 and GAPDH genes. Subsequently, their pathogenicity was evaluated by inoculating healthy cacao pods and measuring the damage caused. The 16 isolates were identified as follows: from the gloeosporioides complex, C. siamense 6, C. chrysophilum 6, C. theobromicola 2 and from the boninense complex, C. karstii 2. The most frequently found species were those that caused symptoms, especially C. siamense, to which the strains were isolated from symptomatic pods belonged. This work provides relevant and accurate information about the diversity of Colletotrichum species that colonize cocoa plantations and identifies which species might cause the disease known as anthracnose. Additionally, it allows for a more precise diagnosis and consequently better treatment.

Environmental enrichment using low walls and perches improves broiler welfare, without compromising productivity

2025-03-24T12:47:44+00:00

The study evaluated the impact of different environmental enrichment strategies on the performance and welfare of commercially raised broilers. The research, conducted in Paraná, Brazil, involved 690 birds allocated to three types of environments: control, with a low wall, and with a perch. The performance of the birds was monitored through indicators such as feed conversion, live weight (plucked and eviscerated), and cut yields (wing, thigh, drumstick, breast, and back weight). There were no significant differences in feed conversion and yields between the environments, except for wing weight, which was higher in environments with a perch for males. Females raised in an environment with a low wall showed higher live and eviscerated weight, while thigh weight was lower in environments with a perch. Welfare variables, such as Latency to Lie and Fluctuating Asymmetry, showed no significant differences between the environments. However, females in the control and low wall environments had a higher incidence of calluses on their feet compared to those in the perch environment. Joint injuries (Hock Health) did not show significant differences between the types of enrichment. These results suggest that, although environmental enrichment may benefit some aspects of welfare, its impact on broiler performance and joint health needs to be better understood, particularly in relation to the long-term effects of different enrichment types on locomotor health, muscle development, and the prevention of joint injuries. Future studies should focus on the physiological mechanisms behind these effects, including the role of enrichment in reducing stress and promoting more natural behaviors that may influence bone density and joint function.

Intelligent biofilm with blueberry extract, rice straw nanocellulose and polyvinyl alcohol: Characterization and its application in visual freshness monitoring in tilapia fillets

2025-03-24T13:03:48+00:00

Intelligent packaging represents a sustainable solution for food preservation by enabling the monitoring of freshness through chromatic changes. In this study, a biofilm based on polyvinyl alcohol (PVA), nanocellulose (NC) extracted from rice straw and blueberry extract was developed and evaluated for its performance as a visual freshness indicator in tilapia fillets. Nanocellulose, obtained by TEMPO oxidation, exhibited proper integration into the polymeric matrix according to transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and X-ray diffraction analysis. The biofilms improved their mechanical properties with the addition of NC, by increasing tensile strength and reducing water solubility. However, the incorporation of anthocyanins increased solubility and water vapor permeability due to their hydrophilic character. Despite this, their high chromatic sensitivity to pH allowed for color changes: red in acidic media (pH 2-4) and green/brown in alkaline media (pH > 9). These visual changes validate the potential of anthocyanins as freshness indicators, positioning biofilms as a functional and sustainable alternative to conventional packaging. In addition to enabling real-time monitoring, these biofilms can contribute to reducing food waste and fostering more sustainable solutions in the packaging industry, with significant potential for innovative commercial applications.

Energy efficiency of heating machines and its effects on broiler's performance and welfare

2025-03-24T13:27:54+00:00

The increasing global demand for animal protein has driven the broiler industry to optimize production systems and better understand limiting factors affecting performance. This study evaluated four different heating systems to determine their correlation with climatic variables, zootechnical performance, pellet fuel consumption, and energy usage. Data were obtained from a private broiler integration company in Southwest Paraná, Brazil, specializing in the griller broiler category. The study covered a 28-day housing period for 12 flocks (both male and female), each consisting of approximately 120,000 birds, for 28 days. The analyzed variables included indoor and outdoor environmental temperature, relative air humidity, carbon dioxide (CO₂) concentration inside the poultry houses, feed conversion ratio, weight gain, pellet fuel consumption, and energy consumption. Statistical analyses were performed using descriptive statistics and Principal Component Analysis (PCA) in R software. Results indicated that correlations among variables were generally weak. However, environmental conditions had the greatest influence on broiler performance. The first principal component explained 74.1% of the total variance, with minimum CO₂ concentration, external temperature, minimum and maximum internal temperature, and pellet fuel consumption being key contributing factors. The second principal component included maximum CO₂ concentration, weight gain, and minimum internal and external relative humidity. Among the evaluated heating systems, the fourth machine tested exhibited the lowest pellet fuel consumption while maintaining satisfactory weight gain and feed conversion rate despite its relatively high energy consumption. These findings suggest that temperature control and pellet fuel consumption are critical factors in optimizing broiler production efficiency, ultimately contributing to improved growth performance and resource utilization.

Evaluating light intensity, whey concentration, and pH to enhance biomass and biofuel precursor accumulation in Chlorella vulgaris: A kinetic and experimental approach

2025-04-15T13:19:48+00:00

Finding alternatives to fossil fuels is important to mitigate climate change. This study investigates the development of Chlorella vulgaris under different levels of light intensities, whey, and pH from a Box-Behnken experimental design. Maximum biomass growth and lipids/carbohydrate content were measured as response variables. The aim is to understand how the microalga responds to various environmental conditions to optimize its growth and biofuel precursors accumulation. The modified Gompertz kinetic model was adjusted to experimental data to understand how the studied conditions impact the growth rate. As a response, it reached production of 2.17 gbiomass·L^-1 at high level of intensity light, whey, and pH. The experiments indicated that the accumulation of lipids/carbohydrates is directly correlated with light intensity; however, the levels of whey concentration and pH played a different role in the production of these compounds, obtaining 88 mglipid·gbiomass^-1 and 14.54 mgcarbohydrate·gbiomass^-1. Finally, the results showed that under light stress (continuous lighting, which can affect biomass growth due to the diurnal cycle of light and darkness), a high availability of nutrients, and an adequate pH an antagonistic relationship in the synthesis of lipids and carbohydrates was observed, that is, as the concentration of lipids increases, the concentration of carbohydrates decreases. Indicating that these compounds compete for the same carbon precursor and that the microalga prefers to increase the synthesis of lipids instead of carbohydrates since the energy content of lipids is higher than that of carbohydrates.

Identification of vulnerable areas to flash floods using weighted sum analysis and unsupervised machine learning in arid regions of the northern Atacama Desert

2025-04-15T13:41:59+00:00

In recent decades, global warming has triggered significant changes in the hydrological cycle, leading to various disasters, especially contrasting events such as droughts and floods. These occurrences have also been recorded in the Atacama Desert, resulting in considerable economic losses worldwide, in Latin America, in Peru, and within the study region. The primary objective of this study is to obtain fundamental morphometric parameters, including basic spatial, linear, shape, and landscape aspects through the integration of GIS tools and artificial intelligence, enabling the identification of flood-prone areas within micro-watersheds. The studied basin is located at the head of the Atacama Desert, in southern Peru, where various lithological and hydro-geomorphological structures influence its vulnerability to floods. To assess flood vulnerability in the Caplina River micro-watersheds, 16 morphometric parameters were precisely analyzed, identifying areas of high vulnerability that require basin management measures. The results show that the hydrological response of the Caplina Basin is strongly influenced by its morphometric characteristics, with micro-watersheds in the middle and lower sections exhibiting higher susceptibility to flash floods. These findings aim to support urban planning and watershed management, offering insights for policymakers to develop flood mitigation strategies and enhance infrastructure resilience.

Caracterización morfológica, molecular y patogenicidad de aislados de Rhizoctonia causantes de la mancha bandeada de la vaina del maíz en el norte de Sinaloa

2025-04-15T13:55:45+00:00

La producción de maíz es afectada por hongos del género Rhizoctonia. El objetivo de este estudio fue caracterizar mediante morfología, análisis de secuencias de ADN y patogenicidad aislados de Rhizoctonia asociados a maíz con síntomas de mancha bandeada de la hoja en lotes comerciales del norte de Sinaloa. Se recolectaron plantas enfermas en los municipios de Ahome, el Fuerte y Guasave, obteniendo 27 aislados. La caracterización morfológica en PDA mostró colonias con micelio blanquecino a café, se observó la liberación de pigmento en el medio, esclerocios amorfos, rojos y cafés, con un diámetro <1 mm, caracteres descritos para Rhizoctonia. Para la caracterización molecular, se extrajo ADN genómico, se amplificó por PCR parte del gen RPB2, y los productos amplificados se secuenciaron. El análisis filogenético confirmó la identificación de 18 aislados como Rhizoctonia zeae, y 9 aislados como Rhizoctonia solani. Los aislados de R. solani corresponden al grupo de anastomosis (AG): AG-4. 3 de ellos corresponden al subgrupo de anastomosis AG-4 HGI y el 6 al subgrupo AG-4 HGIII. La patogenicidad y severidad de los aislados se evaluó en plantas de maíz a los 34 días después de la siembra, mostrando diferencias significativas (p > 0,05). Este estudio permitirá generar estrategias de manejo para la enfermedad y futuras investigaciones en control biológico y químico de especies de Rhizoctonia.

Distinctive signs as an alternative for the revitalization of the productive system of ocañera onion (Allium cepa L.): An analysis of scientific trends

2025-04-15T14:13:11+00:00

The current context of agribusiness is framed by three major drivers: business models based on bioeconomy and circular economy; mechanisms that ensure quality, safety, and traceability throughout the supply chain; and aspects of the Trade-Related Intellectual Property Rights (TRIPS) agreement. The latter has become a differential factor for both comparative and competitive advantage and is recognized as a potential enabler or constraint for the positioning of primary, minimally processed, and transformed agricultural products. In the case of Ocañera red onion as a primary product, access to distinctive signs covered by the TRIPS agreement, such as denomination of origin or geographical indication, would benefit the promotion of its cultivation, protect trade against homologous varieties from neighboring countries introduced without restriction, and facilitate the promotion of characteristics related to its bioactive and functional components beyond organoleptic properties. For this research, a methodological design based on mixed methods of scientometrics, systematic literature review, and qualitative meta-analysis was implemented, aimed at identifying research trends in distinctive signs for primary agricultural products. From these trends and focusing on specific information about vegetables, enabling and restrictive factors related to distinctive signs were identified. These factors were used to analyze homologous cases of distinctive signs reported for primary agricultural products of the Allium genus. Finally, key factors were classified into five categories related to regulations, product added value characteristics, territory specificities, available technologies for origin and quality assessment, and market dynamics and merged in a five-step route to undertake a certification process for distinctive signs for Ocañera red onion.

Semillas como subproducto del procesamiento de frutas en la industria de alimentos: Composición proximal, perfil fitoquímico y aprovechamiento en el marco de la economía circular

2025-03-24T13:44:48+00:00

Este estudio analiza el potencial de 12 semillas de la región del Perú como subproducto del procesamiento de frutas como una alternativa sostenible para la reducción de desechos y la valorización de compuestos bioactivos. Se destaca su composición química y el papel que pueden desempeñar en la recuperación de compuestos bioactivos con propiedades antioxidantes, antimicrobianas y funcionales. Abordando la posibilidad de utilizar los subproductos de frutas en diversos sectores industriales, como el alimentario, farmacéutico y nutracéutico, contribuyendo así a la economía circular y a un manejo más sostenible de los recursos naturales. La revisión menciona la importancia de abordar desafíos como la presencia de antinutrientes y contaminantes, así como la evaluación de métodos de procesamiento que permitan reducir estos compuestos, resaltando la necesidad de garantizar su seguridad para el consumo y su viabilidad en distintos sectores, incluyendo el alimentario, cosmético y farmacéutico.

Biomass briquettes: Raw material, technologies and densification parameters, quality and future challenges

2025-04-15T14:22:52+00:00

The implementation of renewable energy is a viable option to reduce the use of fossil fuels and polluting emissions. Biomass is an excellent renewable energy source and is cleaner than coal. It can be obtained from organic inputs such as wood and agricultural waste and, if used sustainably, can meet the energy needs of various sectors. Densification is a technology with the potential to convert lignocellulosic waste into clean and sustainable solid biofuels. Densification involves compacting loose biomass particles using a mechanical press to produce sustainable solid biofuels with low pollutant content that are not dependent on fossil fuels. The important parameters during the manufacturing process are pressure, temperature, residence time in the press and shape of the briquettes. The production of briquettes imparts certain important properties to the briquettes, such as mechanical strength, density, combustion time and calorific quality. These properties depend on the raw material, binder and pressing process and are of utmost importance during transportation, handling and combustion of briquettes. In accordance with the above, this paper analyzes and describes the properties of different agricultural residues used in the production of briquettes and their potential as a sustainable energy source, as well as the properties that must be evaluated to define the quality of the briquettes. One of the current and future challenges is to improve the processes for producing briquettes using residual biomass and, to the minimum extent possible, binders that favor their energy and mechanical properties.

Actinobacterias: Fuente de metabolitos secundarios antifúngicos para la sostenibilidad agrícola

2025-04-15T14:29:05+00:00

Existe la necesidad de nuevas fuentes alternativas de antifúngicos exógenos para reemplazar las que se emplean actualmente en la agricultura. Las actinobacterias son bacterias grampositivas con una extensa variedad de metabolitos secundarios, las cuales producen alrededor de dos tercios de todos antibióticos de origen natural en uso clínico actual, así como muchos compuestos anticancerígenos, antihelmínticos y antifúngicos. Como consecuencia, estas bacterias son de gran importancia para la biotecnología agrícola, ya que pueden producirse y aplicarse en campos que no promueven resistencia entre los hongos que atacan a las plantas. Esta revisión presenta las investigaciones realizadas en cuanto a la identificación de metabolitos con propiedades fúngicas donde se destacan las principales especies involucradas en la producción de metabolitos que se están utilizando o podrían explorarse en la agricultura como bioproductos para promover la salud y la sostenibilidad de las plantas. Esta revisión amplia los conocimientos para futuras investigaciones centradas en los campos de la genómica, proteómica, metabolómica, biología sintética y ecología para la investigación en nuevos compuestos antimicrobianos para combatir la resistencia a los antifúngicos y desarrollar bioproductos más compatibles con el ambiente.