Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

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.

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.

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.

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.

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.

The objective of this study was to conduct agricultural zoning of climate risk for quinoa cultivation. Data from 38 meteorological stations of the National Meteorology and Hydrology Service in Puno region were used. The zoning was based on the development of the water balance model, applying the water requirement satisfaction index (ISNA), for two levels of soil available water capacity (115 mm/m and 145 mm/m). Spatial analysis of the ETr/ETm ratio, obtained from the SARRAZON model, was carried out for each phenological stage through frequency analysis of ISNA values. These data were processed in ArcGIS10.0, using the ordinary kriging interpolation method. Once the maps were generated, they were clipped to the quinoa production zones of the region and classified as follows: for Phase I: low risk (ISNA ≥ 0.65); medium risk (0.55 < ISNA < 0.65) and high risk (ISNA ≤ 0.55), considered for the emergency stage; and for phase III the following ranges were considered: low risk (ISNA ≥ 0.55); medium risk (0.45 < ISNA < 0.55) and high risk (ISNA ≤ 0.45) during flowering and grain filling. September was identified as the month with the highest exposure to climate risk; October presented intermediate conditions; and November was the safest month, showing a predominance of low-risk zones: However, late sowing may expose the crop to critical water deficits during the final phases of quinoa cultivation.

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.

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.

The banana (Musa AAA) is affected by Fusarium oxysporum f. sp. cubense, which causes discoloration in the xylem duct, leading to terminal wilting. The use of plant growth promoting rhizobacteria (PGPR) as a biological control produces different antagonistic compounds and inhibits the growth of various phytopathogens. The objective of the study was based on the molecular identification of rhizobacteria that produce phytohormones with biocontrol activity against Foc-R1. The presence of the 225 bp ChiA gene was observed in PGPR. Phylogenetic analysis of 16S rRNA by sequencing and ERIC-PCR showed genetic variability with the formation of four subgroups. Molecular identification by sequencing the 16S rRNA gene defined the genera as Klebsiella, Enterobacter, and Pseudomonas. There is variation in the biosynthesis of the phytohormones AIA, AG, and AS in strains MH-18, W-417, and FZ 9-7 at 72 h. The identification of Foc-R1 by PCR shows an amplicon of 350 bp. Antagonistic assays of bacterial supernatants from strain FZ 9-7 show 71% mycelial inhibition of Foc-R1 and a decrease in spore production of 2.5X106 spores mL-1. The results provide information on the genetic relationships of PGPRs through the production of secondary metabolites such as proteases, catalases, chitinases, and siderophores, as well as morphological and molecular analysis for the identification of Foc-R1 and its interaction with antagonistic extracts in inhibiting the growth of diseases in bananas and cocoa.

In recent years, nanotechnology has made significant progress in various fields, including agriculture, where nanofertilizers play a pioneering role in improving crop productivity and reducing environmental pollution. In this study, a controlled-release nanofertilizer was developed using chitosan nanoparticles loaded with nitrogen (N), phosphorus (P), and potassium (K). The chitosan nanoparticles (CS-NPs) were prepared via an ionic gelation method using sodium tripolyphosphate and characterized by scanning transmission electron microscopy and infrared spectroscopy. The results revealed that the nanoparticle size ranged from 17.21 nm to 18.32 nm. The controlled release of N, P, and K was evaluated over 240 hours. The nanofertilizer was then applied foliage to Solanum tuberosum seedlings under greenhouse conditions. The findings indicated that the 0.25% chitosan nanofertilizer formulation resulted in nanoparticles with relatively high nutrient absorption capacity, with average values of 4.65 mg/L nitrogen, 198.55 mg/L phosphorus, and 1345.27 mg/L potassium. However, the most effective nanofertilizer treatment was the 1% chitosan nanoparticle formulation loaded with 5 ppm N, P, or K, resulting in the best nutritional characteristics among all the fertilization treatments and a 37% increase in the mass yield of Solanum tuberosum compared with that of the control. These results suggest that NPK-loaded chitosan nanoparticles could be used as foliar sprays to produce more nutritious and higher-yielding crops.