Scientia Agropecuaria

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

Valdinar Ferreira Melo — 2025-02-18

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.

Foliar phytopathogenic fungi associated with the cultivation of Prunus persica L.: Morphological and molecular identification, and biological control with Trichoderma asperelloides

Ángel Ceballos-Chávez — 2025-02-18

The presence of foliar phytopathogenic fungi causes severe damage to leave and fruits of peach (Prunus persica L.), in producing areas of southern Chihuahua, Mexico, which has caused a decrease in production by 30%. The objective of this work was to identify morphologically and molecularly the foliar phytopathogenic fungi associated with the peach tree crop, evaluating the pathogenicity in one-year-old plants against Trichoderma asperelloides. Leaves with brown and brown lesions were collected from mummified fruits on the plant from 19 commercial peach orchards distributed in three municipalities of regional and national production in the State of Chihuahua, Mexico. Fungal identification of four representative isolates was performed using morphological methods. characterization and phylogenetic analysis based on the internal transcribed spacer region (ITS1 and ITS4) of ribosomal DNA, part of the translation elongation factor 1-alpha (TEF) a second secondary primer for each of the genera for, Collectotrichum ACT-512F and ACT-583R, Fusarium with EF1. For plant confrontations, a concentration of 1x10⁶ conidia was inoculated. mL-1 of pathogens such as T. asperelloides, evaluating leaf diameter and length, height, severity and incidence. It was possible to identify the presence of Fusarium sambucinum, Collectotrichum gleosporoides and Monilinia frutícola, in addition the B-F-M1-A2-ACCH-3 strain of F. Sambucinum obtained the highest values in the inhibition of the response variables and in severity Monilinia frutícola presented 61.23% as the highest value. It is recommended to use strain 3 as a biological control of foliar phytopathogens.

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

Fernando Espinoza-Lozano — 2025-02-18

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

Claudia Helena Ferreira Zago-Dias — 2025-03-24

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

2025-03-24

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

Diandra Masurana-Jahn — 2025-03-24

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

Daniel Montalvo — 2025-04-15

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

Edwin Pino-Vargas — 2025-04-15

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.

Morphological, molecular and pathogenic characterization of Rhizoctonia isolates causing a banded spot of corn sheath in northern Sinaloa

Karen Rabago-Zavala — 2025-04-15

Corn production is affected by fungi of the genus Rhizoctonia. The objective of this study was to characterize, using morphology, DNA sequence analysis, and pathogenicity, Rhizoctonia isolates associated with corn with banded leaf spot symptoms in commercial fields in northern Sinaloa. Diseased plants were collected in the municipalities of Ahome, El Fuerte, and Guasave, obtaining 27 isolates. Morphological characterization on PDA showed colonies with whitish to brown mycelium, pigment release into the medium, and amorphous, red and brown sclerotia with a diameter < 1 mm, characteristics described for Rhizoctonia. For molecular characterization, genomic DNA was extracted, part of the RPB2 gene was amplified by PCR, and the amplified products were sequenced. Phylogenetic analysis confirmed the identification of 18 isolates as Rhizoctonia zeae and 9 isolates as Rhizoctonia solani. The R. solani isolates correspond to the anastomosis group (AG): AG-4. Three of them correspond to the anastomosis subgroup AG-4 HGI and the other 6 to the subgroup AG-4 HGIII. The pathogenicity and severity of the isolates were evaluated in corn plants 34 days after planting, revealing significant differences (p > 0.05). This study will allow the development of disease management strategies and future research into biological and chemical control of Rhizoctonia species.

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

Diego Hernando Flórez-Martínez — 2025-04-15

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.

Seeds as by-product of fruit processing in the food industry: Proximate composition, phytochemical profile and utilization in the framework of the circular economy

Luz María Paucar-Menacho — 2025-03-24

This study analyzes the potential of 12 seeds from the Peruvian region as by-products of fruit processing, presenting them as a sustainable alternative for waste reduction and the valorization of bioactive compounds. It highlights their chemical composition and the role they can play in recovering bioactive compounds with antioxidant, antimicrobial, and functional properties. The study explores the possibility of utilizing fruit by-products in various industrial sectors, such as food, pharmaceutical, and nutraceutical industries, thereby contributing to the circular economy and a more sustainable management of natural resources. The review emphasizes the importance of addressing challenges such as the presence of antinutrients and contaminants, as well as evaluating processing methods that can reduce these compounds, highlighting the need to ensure their safety for consumption and their viability in different sectors, including food, cosmetic, and pharmaceutical industries.

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

Y. Sanchez-Roque — 2025-04-15

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.

Actinobacteria: Source of antifungal secondary metabolites for agricultural sustainability

Harold Alexander Vargas Hoyos — 2025-04-15

There is a need for new alternative sources of exogenous antifungals to replace those currently used in agriculture. Actinobacteria are gram-positive bacteria with a wide variety of secondary metabolites, which produce around two-thirds of all naturally occurring antibiotics in current clinical use, as well as many anticancer, anthelmintic and antifungal compounds. Consequently, these bacteria are of great importance for agricultural biotechnology, since they can be produced and applied in fields that do not promote resistance among fungi that attack plants. This review presents the research carried out regarding the identification of metabolites with fungal properties, highlighting the main species involved in the production of metabolites that are being used or could be explored in agriculture as bioproducts to promote plant health and sustainability. This review expands knowledge for future research focused on the fields of genomics, proteomics, metabolomics, synthetic biology, and ecology for the investigation of novel antimicrobial compounds to combat antifungal resistance and develop more environmentally friendly bioproducts.