Resumen Introducción. Durante las últimas décadas, se ha observado un creciente interés por parte de los consumidores en productos agroalimentarios sostenibles. Debido a esto, han surgido normativas voluntarias que se han convertido en una herramienta para promover la sostenibilidad en la producción y el consumo en las cadenas de valor agroalimentarias. Objetivo. Evaluar el perfil de los consumidores y el grado de conocimiento sobre sellos de sostenibilidad de los productos agrícolas en los mercados costarricenses. Materiales y métodos. Durante los meses de octubre y noviembre de 2021, se llevó a cabo una encuesta virtual a nivel nacional a través de la plataforma Qualtrics de la que se recopilaron 397 respuestas válidas. Los sellos de sostenibilidad considerados fueron certificaciones de producción orgánica, comercio justo, denominación de origen, marca país Esencial Costa Rica y carbono neutral. Se empleó el modelo de regresión de Poisson (PRM) para estudiar el comportamiento de las variables, con el software Stata versión 16.0. Resultados. El sello Esencial Costa Rica es el más reconocido. Las personas que residen en la Gran Área Metropolitana están más familiarizadas con diversos sellos. La variable de ingresos resultó ser un factor significativo; las personas con ingresos más altos tienden a identificar y valorar más los sellos de sostenibilidad. Los niveles de conocimiento y consumo de productos certificados aumentan cuando el consumidor posee algún vínculo con el sector agropecuario. Conclusiones. El interés de las personas en productos certificados no se ve reflejado en el comportamiento de compra, debido, en parte, al precio de los productos, la falta de confianza o el exceso de información en las etiquetas. Los hallazgos del estudio permiten a las empresas definir sus estrategias de comercialización según las características de los consumidores de estos productos diferenciados.

Abstract Introduction. Over the last few decades, there has been growing interest on the part of consumers in sustainable agri-food products. As a result, voluntary standards have emerged as a tool to promote sustainability in production and consumption in agri-food value chains. Objective. To evaluate the profile of consumers and the degree of knowledge of sustainability seals for agricultural products in Costa Rican markets. Materials and methods. During October and November 2021, a nationwide virtual survey was conducted through the Qualtrics platform, from which 397 valid responses were collected. The sustainability seals considered were certifications of organic production, fair trade, denomination of origin, nation brand Essential Costa Rica, and carbon neutral. The Poisson regression model (PRM) was used to study the behavior of the variables, using Stata software version 16.0. Results. The Essential Costa Rica seal is the most recognized. People residing in the Greater Metropolitan Area (GAM) are more familiar with various seals. The income variable turned out to be a significant factor; those with higher incomes tend to identify and value sustainability seals more. The levels of knowledge and consumption of certified products increase when the consumer has some link to the agricultural sector. Conclusions. People’s interest in certified products is not reflected in their purchasing behavior, due in part to the price of the products, lack of trust or excessive information on labels. The findings of the study allow companies to define their marketing strategies according to the characteristics of the consumers of these differentiated products.

RESUMO: Vários resíduos agroindustriais podem ser utilizados para a extração de açúcares por meio de reações químicas. Este estudo avalia a extração de açúcares totais e açúcares redutores de resíduos de casca de banana (Musa paradisiaca) e laranja (Citrus sinensis) usando reações de hidrólise ácida para saber se há diferença entre a concentração de açúcares presentes, analisando o efeito de diferentes concentrações de ácido sulfúrico e tempos de reação. Foi utilizado o delineamento experimental 2 × 4 × 2 completamente aleatório, avaliando dois tipos de resíduos, expostos a quatro concentrações de ácido sulfúrico (4, 6, 8 e 10% V/V) em tempos de reação de 2 e 4 horas. Totalizando 16 tratamentos com três repetições. As unidades experimentais foram compostas por frascos de vidro de borosilicato semi-submersos em um banho de óleo vegetal e montados em uma torre de resfriamento rápido, de onde foram obtidos os xaropes de glicose analisados. Os resíduos de casca de laranja apresentaram os maiores valores de extração de açúcares redutores com concentração de 8% de ácido sulfúrico, apresentando média de 16,46 mg L-1 ± SE = 0,591 e tempo ótimo de reação de hidrólise de 2 horas. Com 4 horas de tempo de reação, a extração de açúcares redutores foi maior nos resíduos de casca de laranja em comparação com os resíduos de casca de banana. Ambos os resíduos se mostraram adequados para a extração de açúcar, apresentando uma valiosa oportunidade de utilização em regiões onde estão prontamente disponíveis. Eles podem ser empregados em processos de fermentação para a produção de bioetanol.

ABSTRACT Several agro-industrial residues can be utilized for the extraction of sugars through chemical reactions. This study evaluated the extraction of total sugars and reducing sugars from banana (Musa paradisiaca) and orange (Citrus sinensis) peel residues using acid hydrolysis. It also investigated if there is a difference between the concentration of sugars present, and analyzed the effect of different sulfuric acid concentrations and reaction times. A completely randomized 2 × 4 × 2 experimental design was used to evaluate two types of waste, exposed to four concentrations of sulfuric acid (4, 6, 8 and 10% V/V) at reaction times of 2 and 4 hours. This amounted to 16 treatments with three repetitions. The experimental units consisted of borosilicate glass flasks, half submerged in a bath of vegetable oil and assembled in a rapid cooling tower from which the analyzed glucose syrups were obtained. The orange peel residues showed the highest values of reducing sugar extraction with 8% sulfuric acid concentration, presenting mean of 16.46 mg L-1 ± SE = 0.591 and optimal hydrolysis reaction time of 2 hours. With 4 hours reaction time, the extraction of reducing sugars was higher in orange peel residues compared to banana peel residues. Both residues proved to be suitable for sugar extraction, presenting a valuable opportunity for utilization in regions where they are readily available. They can be employed in fermentation processes for bioethanol production.

Abstract Introduction: In Paraguay, the relationship between drug trafficking and politics dates back to the last stage of the dictatorship (1954-1989), although it began an expansive process in the following years. Objective: Analyze how drug trafficking maintained and expanded its influence in the country thanks to the establishment of increasingly close relations between organized crime and the political class that emerged with democracy. Methodology: The production of information combines qualitative and ethnographic approaches, with observations, interviews and informal conversations with different key actors in different regions of the country over the last five years, in addition to an exhaustive documentary review. Conclusions: The findings suggest that for the Paraguayan context the concept of narco-politics may no longer be sufficient, being more appropriate the use of mafia, since there is an overcoming of the classic complicities of exchange of favors (impunity for financing) between politics and organized crime, installing an organic system of diffuse illegality, including: politicians, criminals, white-collar professionals, businessmen; which guarantees widespread profit and impunity. The level of interpenetration between criminality, society and institutions is reaching such deep levels that the very stability of democracy is being called into question.

Resumen Introducción: en Paraguay, la relación entre política y narcotráfico se remonta a la última etapa de la dictadura (1954-1989), aunque inició un proceso expansivo en los años siguientes. Objetivo: analizar cómo el narcotráfico mantuvo y amplió su incidencia en el país gracias a la instalación de relaciones cada vez más estrechas entre el crimen organizado y la clase política surgida con la democracia. Metodología:la producción de información combina los enfoques cualitativo y etnográfico; se han realizado en los últimos cinco años observaciones, entrevistas y conversaciones informales con diferentes actores claves, en distintas regiones del país, además de una exhaustiva revisión documental. Conclusiones:los hallazgos sugieren que, para el contexto paraguayo, el concepto de narcopolítica puede resultar insuficiente, y ser más adecuado el de mafia, ya que existe una superación de las clásicas complicidades de intercambio de favores (impunidad por financiación) entre política y crimen organizado y en su lugar se ha instalado un sistema orgánico de ilegalidad difusa, que incluye: políticos, criminales, profesionales de cuello blanco, empresarios; lo cual garantiza ganancias e impunidad generalizadas. El nivel de compenetración entre criminalidad, sociedad e instituciones está llegando a niveles tan profundos que ponen en entredicho la misma estabilidad democrática.

ABSTRACT Sisal (Agave sisalana Perrine), a crucial natural fiber source, exhibits varying yields in China’s Guangdong and Guangxi regions. This groundbreaking study sampled soil and sisal leaves from these production hubs to explore the interplay among soil pH, enzyme activity, microorganisms, and sisal nutrition. Using PCR and high-throughput sequencing, results indicate Guangdong’s soil is mildly acidic, contrasting with Guangxi’s neutral to slightly alkaline soil. Both regions show a robust correlation between soil pH and nutrient availability (organic matter, P, K). Enhanced soil enzyme activity is observed at higher pH levels (6.09, 7.39). Dominant bacterial phyla Acidobacteria, Proteobacteria, and Actinobacteria peak at pH 7.39, 6.09, and 5.41, respectively. Fungal phyla Ascomycota, Basidiomycota, and Mortierellomycota thrive at pH 4.23, 7.39, and 6.48. Sisal leaves display optimal nutrient levels at specific pHs: N, P, and K at pH 6.09; Ca at pH 7.39; Mg at pH 6.48. Functional predictions reveal fungal abundance varies with pH, while bacterial functions like metabolism, disease resistance, and environmental adaptation are bolstered in Guangxi’s alkaline soils compared to Guangdong’s acidic ones. These findings provide a scientific basis for optimizing sisal cultivation management.

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.

Abstract In the production of kale, nitrogen is one of the nutrients that the plant needs in greater quantity. Its application must be divided throughout the cycle, due to the loss by leaching. The objective of the research was to evaluate the effect of splitting organic fertilizers in topdressing on the production of kale. The experimental design was randomized blocks, with four replications, with seven treatments being evaluated in a 2 x 3 + 1 factorial scheme, the first factor was the fertilizers (castor bean cake and bokashi) and the second the application intervals (7; 14 and 21 days), in addition to the control without topdressing fertilization. The amount of each fertilizer was calculated to provide the same dose of N (40 kg ha-1) every 21 days. The following characteristics were evaluated: plant height (PH), stem diameter (SD), number of leaves per plant (NLP), leaf fresh matter mass (LFMM), leaf length at the beginning (LLB), middle (LLMe) and end (LLE) of the cycle and “SPAD” index. There was no interaction between the factors, for any characteristic evaluated. For all traits, the values observed in control was lower than treatments with topdressing. The increases of treatments of factorial in relation to the control were 37.8% (plant height); 31.8% (SD); 157.1% (NLP); 213.5% (MLFMM); 7.6% (LLB); 80.2% (LLMe) and 126.6% for the “SPAD” index. It is recommended to use castor bean cake and split it every 21 days as it results in less labor for application.

RESUMO A soja integral desativada (SID) foi estudada em suínos para determinar o valor energético, por meio de um ensaio de metabolismo, e avaliar o efeito da SID e da protease no desempenho, nas características da carcaça e na viabilidade econômica. Foi realizado um ensaio de metabolismo com suínos (53,80±4,15kg) para determinar os coeficientes de digestibilidade da matéria seca (MS), da matéria orgânica (MO) e da proteína bruta (PB), a energia digestível (ED), a energia metabolizável aparente (EMA) e a EMA corrigida pelo nitrogênio (EMAn). Para o ensaio de desempenho, foram utilizados 60 suínos machos imunocastrados e 60 suínos fêmeas (30,09 ± 1,46kg), em arranjo fatorial 2 (sexo) x 2 (com e sem SID) x 2 (protease). Os coeficientes de metabolizabilidade da MS, MO e PB do SID foram de 83,77, 84,43 e 89,18%, respectivamente. Os valores de ED, AME, e AMEn foram 4904 ± 117, 4805±273, e 4656±255kcal/kg, respectivamente. Para o desempenho na fase de crescimento I, a enzima proporcionou um aumento no consumo médio diário de ração. Em termos de viabilidade econômica, a dieta com SID e sem a enzima teve o menor custo por quilograma de peso ganho e proporcionou o maior índice de eficiência econômica e receita líquida. A SID possui um alto valor de energia e, quando usada em dietas para suínos em crescimento e terminação, proporciona um desempenho satisfatório e uma melhor eficiência econômica.

ABSTRACT The inactivated whole soy (IWS) was studied in pigs to determine the energy value through a metabolism trial and evaluate the effect of IWS and protease on performance, carcass traits, and economic viability. Metabolism with pigs (53.80±4.15kg) to determine digestibility coefficients of dry matter (DM), organic matter (OM), and crude protein (CP), digestible energy (DE), apparent metabolizable energy (AME), and nitrogen-corrected AME (AMEn). For the performance trial, 60 immunocastrated male pigs and 60 female pigs (30.09±1.46kg) were used in a 2 (gender) x 2 (with and without IWS) x 2 (protease) factorial arrangement. The DM, OM, and CP metabolizability coefficients of IWS were 83.77, 84.43, and 89.18%, respectively. The DE, AME, and AMEn values were 4904±117, 4805±273, and 4656±255kcal/kg, respectively. In growth phase I, enzyme provided an increase in average daily feed intake. In the economic viability, diet with IWS and without the enzyme had the lowest cost per kilogram of weight gained and provided the highest economic efficiency index and net revenue. The IWS has a high energy value and when used in diets for growing and finishing pigs provides satisfactory performance and better economic efficiency.

Abstract: The aim of this study was to evaluate the environment-performance relationship of surface coating applications on data obtained by measuring the emission rates of volatile organic compounds in polyurethane and water-based varnishes. For this purpose, polyurethane and water-based varnishes from five different companies were applied to the test samples of Entandrophragma cylindricum (sapele) and Piptadeniastrum africanum (dabema), both widely used in the production of urban furniture. Volatile organic compound, hardness and adhesion strength were measured during application. When evaluated in terms of performance, polyurethane varnishes showed superior hardness, while water-based varnishes demonstrated better adhesion after the UV test. The hardness values of polyurethane varnishes before and after the UV aging test were 15,9 s and 79,403 s, respectively, while forwater-based varnishes were , the values were 114,92 s and 75,406 s. The adhesion values of water-based varnishes were 2,885 MPa and 1,18 MPa before and after the UV aging test, and for polyurethane varnishes 3,13 MPa and 1,05 MPa for. When the environment-oriented results were evaluated, the ; emission values of volatile organic compounds in polyurethane varnish applications were found to be significantly higher than those in in water-based varnishes applications. While the total emission rate of volatile organic compounds detected in polyurethane varnishes was 53,63 mg/Nm3, while only one brand of water-based varnishes showed a measurable emission value, recorded at 0,0057 mg/Nm3. The volatile organic compounds emission values of other water-based varnishes were below the device detection limit (<0,0035 mg/Nm3), and therefore could not be measured.

ABSTRACT Biochar can promote crop production and soil quality. However, its characteristics depend on the waste used in its production and its effects may vary according to the species being cultivated and the management adopted. The aim of this study was to evaluate the application of biochar from animal waste on soil quality and the agronomic characteristics of the cowpea. An experiment was set up to test three types of biochar (bovine-BB, swine-SB and poultry-BP), with added fertiliser (BBF, SBF and BPF) and two control treatments, including the addition of calcium magnesium oxide (CT) and calcium magnesium oxide with fertiliser (CTF), giving a total of eight treatments with four replications. There was a respective increase of up to 102.94%, 1048%, 1560% and 360.22% in stem diameter, number of pods, number of grains per pod and stem dry matter from adding the biochar. The poultry biochar increased each of the above parameters even with no added fertiliser. There was no difference in basal soil respiration or β-glucosidase enzyme activity, whereas organic carbon (TOC), total nitrogen (TN), microbial carbon and soil labile carbon were greater with biochar. BBF gave the highest TOC content (24.40 g kg-1), while BP and BPF increased TN by around 61%. The application of biochar + fertiliser contributed to an average reduction of 56% in the soil metabolic quotient. Poultry biochar favoured both the agronomic characteristics of the cowpea and soil quality, while bovine biochar showed more marked results with the addition of fertiliser. However adopted bovineBB, bovineBB BB, BB (bovine-BB swineSB swine SB poultryBP, poultryBP , poultry-BP) BBF, (BBF CT (CT CTF, CTF (CTF) replications 10294 102 94 102.94% 1048 1048% 1560 36022 360 22 360.22 diameter pods βglucosidase β glucosidase activity TOC, (TOC) TN, (TN) 24.40 2440 24 40 (24.4 kg1, kg1 kg 1 kg-1) 61 61% 56 quotient poultry-BP (CTF 1029 10 9 102.94 104 156 3602 36 2 360.2 (TOC (TN 24.4 244 4 (24. kg-1 6 5 102.9 15 3 360. 24. (24 kg- 102. (2 (

Seeking a viable alternative to fossil fuels as the primary energy source, bioethanol has emerged as a promising second-generation fuel derived from lignocellulosic biomass. With Brazil ranking pineapple as the third most produced fruit in temporary crops, this study aims to assess the impact of chemical pretreatment techniques, specifically organosolv and diluted acid, on the residual biomass of Pérola pineapple peel to enhance bioethanol production. Employing an experimental design that incorporates temperature, reaction time, and varying concentrations of organic solvent, the study examines their effects on the susceptibility of the substrate to saccharification for future bioethanol generation. Factors such as alphacellulose, hemicellulose, and lignin were evaluated in triplicate and subjected to statistical analysis using the Tukey test with a confidence level of 95%. Upon application of the pretreatment methods, it was observed that the organosolv solvent approach (utilizing water and ethanol) with sulfuric acid exhibited superior sugar conversion, yielding the highest concentration of xylose at 9.13 g L-1. Additionally, the pretreated biomass contained 1.38 g L 1 of cellobiose, 3.11 g L-1 of arabinose, and 3.76 g L-1 of glucose. This technique demonstrates promising potential for obtaining fermentable sugars crucial for bioethanol production. source secondgeneration second generation crops techniques production temperature time alphacellulose hemicellulose 95 95% methods utilizing ethanol conversion 913 9 13 9.1 L1. L1 1. Additionally 138 38 1.3 cellobiose 311 3 11 3.1 L- arabinose 376 76 3.7 glucose 91 9. 31 3. 37 7

ABSTRACT Theobroma cacao (cocoa) in the Dominican Republic is one of the main export items, registering a sustained growth in the last five years. There are more than 36,000 producers in the country, indirectly benefiting more than 300 thousand people. The country has great potential for cocoa production, but due to the lack of fertilization of the plantations combined with the lack of information on the contribution of nutrients from the mineralization of biomass in the production systems, low yields are presented. The study was carried out in the Duarte province in the period from July 2016 to June 2017, with the objective of quantifying the biomass production in four agroforestry systems: cocoa in monoculture (C), cocoa plus Erythrina spp (C+ Am), cocoa plus Persea americana (C+Ag ), and cocoa plus citrus (C+Ci). A multifactorial experimental design 4x15x12 was used: with four agroforestry systems, in fifteen locations and twelve sampling dates, where each farm was considered as a replicate. Four pipe and sack mesh traps were installed per farm, with an area of 1 m2. The average biomass by location and date was analyzed by analysis of variance and Duncan test (P = 0.05 %). The highest average biomass production was obtained in C + Am with 49.3 T ha-1 year-1 (41.08% of the total). It was followed by system C with 27.02 T ha-1 year-1, C + Ag with 22.2 T ha-1 year-1 and C + Ci with 17.2 T ha-1 year-1. The annual net production was 120 T ha-1 year-1, of which 115.2 T ha-1 year-1 was attributable to the species under study, and 4.2 T ha-1 year-1 to other species. The values demonstrate a high biomass production in agroforestry systems associated with cocoa.

RESUMO O cacau (Theobroma cacao L.) na República Dominicana é um dos principais itens de exportação, registrando crescimento sustentado nos últimos cinco anos. São mais de 36 mil produtores no país, beneficiando indiretamente mais de 300 mil pessoas. O país tem grande potencial para a produção de cacau, mas devido à falta de fertilização das plantações aliada à falta de informações sobre a contribuição dos nutrientes provenientes da mineralização da biomassa nos sistemas de produção, ocorrem baixos rendimentos. O estudo foi desenvolvido na província Duarte no período de julho de 2016 a junho de 2017, com o objetivo de quantificar a produção de biomassa em quatro sistemas agroflorestais: cacau em monocultura (C), cacau mais papoula (Erythrina spp. Walp.) (C+ Am ), cacau mais abacate (Persea Americana Mill.) (C+Ag) e cacau mais cítricos (C+Ci). Foi utilizado um delineamento experimental em arranjo multifatorial 4x15x12: com quatro sistemas agroflorestais, em quinze localidades e doze datas de amostragem, onde cada fazenda foi considerada uma repetição. Foram instaladas quatro armadilhas com tubo de PVC e tela de saco por fazenda, com área de 1 m2. A biomassa média por local e data foi analisada por análise de variância e teste de Duncan (p=0,05 %). A maior produção média de biomassa foi obtida em C+Am com 49,3 T/ha/ano (41,08 % do total). Seguiu-se o sistema C com 27,02 T/ha/ano, C+Ag com 22,2 T/ha/ano e C+Ci com 17,2 T/ha/ano. A produção líquida anual foi de 120 T/ha/ano, sendo 115,2 T/ha/ano atribuíveis às espécies em estudo e 4,2 T/ha/ano às demais espécies. Os valores demonstram uma elevada produção de biomassa nos sistemas agroflorestais associados ao cacau.

RESUMEN Theobroma cacao (cacao) en República Dominicana es uno de los principales rubros de exportación, registrando un crecimiento sostenido en los últimos cinco años. Son más de 36.000 productores en el país, beneficiando indirectamente a más de 300 mil personas. El país tiene un gran potencial para la producción de cacao, pero debido a la falta de fertilización de las plantaciones combinado con la falta de información sobre el aporte de nutrientes provenientes de la mineralización de biomasa en los sistemas de producción, se presentan bajos rendimientos. El estudio se desarrolló en la provincia Duarte en el período de julio 2016 a junio 2017, con el objetivo de cuantificar la producción de biomasa en cuatros sistemas agroforestales: cacao en monocultivo (C), cacao más Erythrina spp. (C+ Am), cacao más Persea americana (C+Ag), y cacaos más cítricos (C+Ci). Se usó un diseño experimental en arreglo multifactorial 4x15x12: con cuatro sistemas agroforestales, en quince localidades y doce fechas de muestreo, donde se consideró a cada finca como una repetición. Se instalaron cuatro trampas de tubo y maya de saco por finca, con un área de 1 m2. La biomasa promedio por ubicación y fecha se analizó mediante análisis de varianza y prueba de Duncan (P=0,05 %). La mayor producción promedio de biomasa se obtuvo en C+Am con 49,3 T ha-1año-1 (41,08 % del total). Le siguió el sistema C con 27,02 T ha-1año-1, C+Ag con 22,2 T ha-1año-1 y C+Ci con 17,2 T ha-1año-1. La producción neta anual fue de 120 T ha-1año-1, siendo 115,2 T ha-1año-1 atribuible a la especie en estudio, y 4,2 T ha-1año-1 a otras especies. Los valores demuestran una alta producción de biomasa en los sistemas agroforestales asociados al cacao.

Resumne Introducción. Los bioestimulantes son productos orgánicos que mejoran la absorción de nutrientes de las plantas, entre ellos sustancias húmicas, aminoácidos, extractos de algas y bacterias promotoras del crecimiento de las plantas; y se han identificado numerosos mecanismos y de selectividad de bioestimulantes para nutrientes específicos. Objetivo. Determinar el efecto de la aplicación de bioestimulantes en la producción de pepino y melón en invernadero. Materiales y métodos. Se evaluaron los bioestimulantes BioRemedy 2,0 g L-1, Grand Sill 2,0 g L-1, Fossil 5,0 g L-1, L-Amino 2,0 mL L-3 y un Testigo (con aplicación de solo agua), en tres estadios de desarrollo de los cultivos. El experimento fue establecido bajo un diseño experimental completamente aleatorio desbalanceado con 10 tratamientos. Cada unidad experimental estuvo constituida por tres hileras. Las variables de respuestas fueron: altura de planta, grosor de tallo, número de frutos, tamaño del fruto, volumen del fruto y peso de frutos (rendimiento). Resultados. Los bioestimulantes tuvieron mejor efecto en la altura de planta, diámetro de tallo, volumen de fruto en el pepino. En melón los bioestimulantes tuvieron mayor efecto en el volumen de fruto y peso. Se encontró que Fossil mostró mejor efecto para la altura de planta en ambas especies y el BioRemedy resulto ser el mejor para el diámetro de tallo, volumen de fruto, peso de fruto y número de frutos. Conclusión. El BioRemedy fue el mejor bioestimulante para el diámetro de tallo, el volumen y peso de fruto para el cultivo de pepino y melón. El L-amino tuvo mejor respuesta para diámetro de tallo en melón.

Abstract Biostimulants are organic products that improve plant nutrient absorption, for instance humic substances, amino acids, algae extracts and plant growth-promoting bacteria; and numerous mechanisms and selectivity of specific biostimulants for specific nutrients have been identified. Objetive. Determine the effect of the application of biostimulants on the production of cucumber and melon in the greenhouse. Materials and methods. The biostimulants BioRemedy 2.0 g L-1, Grand Sill 2.0 g L-1, Fossil 5.0 g L-1, L-Amino 2.0 mL L-3 and a Control with application of only water were evaluated in three stages of crop development. The experiment was established as a completely randomized unbalanced experimental design with 10 treatments. Each experimental unit consisted of three rows. The response variables were: plant height, stem thickness, number of fruits, fruit size, fruit volume and fruit weight (yield). Results. The biostimulants had a better effect on plant height, stem diameter, and fruit volume for cucumber. For the melon, fruit volume and weight were affected by biostimulants. It was found that Fossil showed the best effect for plant height in both species and BioRemedy turned out to be the best for stem diameter, fruit volume, fruit weight and number of fruits. Conclusion. BioRemedy was the best biostimulant for stem diameter, volume and fruit weight for cucumber and melon cultivation. L-amino had the best response for stem diameter in melon.

Resumen Introducción: Las arqueas metanogénicas (MA) participan en la mineralización anaerobia de la materia orgánica en sedimentos de manglar, su actividad está relacionada con el calentamiento atmosférico por la producción de metano; diversas variables ambientales pueden influir en la dinámica metanogénica y la producción de metano en estos sedimentos. Objetivo: Analizar, mediante técnicas dependientes de cultivo, la abundancia de las arqueas metanógenas viables (AMV) y la producción de metano en diferentes épocas climáticas en los sedimentos del manglar El Morro-La Mancha, Veracruz, Golfo de México. Métodos: De mayo a noviembre 2019, siguiendo un transecto de salinidad, se recolectaron sedimentos del manglar del Morro-La Mancha, en tres localidades, abarcando tres diferentes épocas climáticas, secas (mayo), lluvias (octubre) y nortes (noviembre) (N = 9), cuantificándose la abundancia de las AMV mediante la técnica del Número Más Probable (NMP) con acetato y metanol como substratos; la influencia de los sulfatos en la producción de metano a partir de acetato en microcosmos, se analizó por cromatografía de gases y se evaluaron las variables químicas de salinidad, pH, Eh, carbohidratos, contenido orgánico y carbonatos en los sedimentos. Resultados: Se determinó una abundancia de AMV de 102 a 108 NMP/g de sedimento húmedo, superior a la reportada en otros estudios, dicha abundancia se incrementó cuando se utilizó metanol (104-108 NMP/g sedimento) como sustrato, en comparación con el acetato (102-105 NMP/g sedimento); la producción de metano en los microcosmos aumentó en condiciones libres de sulfatos (29.78-929.75 nmol CH4/mes) y en los sedimentos de la temporada de lluvias. Conclusión: Se destaca la influencia de las condiciones químicas de los sedimentos del manglar sobre la dinámica metanógena, determinándose que, en la temporada de lluvias, una disminución de la salinidad, Eh más electronegativos y el incremento de las fracciones orgánicas favorecieron la metanogénesis.

Abstract Introduction: Methanogenic archaea (MA), participate in the anaerobic mineralization of organic matter in mangrove sediments, their activity is related to atmospheric warming due to the production of methane; several environmental variables can influence the presence of MA and methane production in these sediments. Objective: To analyze, through culture-dependent techniques, viable methanogenic archaea (VMA) in the sediments, and the production of methane from acetate in different climatic periods in the mangrove El Morro-La Mancha, Veracruz, Gulf of Mexico. Methods: From May to November 2019, following a salinity transect, sediment samples from El Morro-La Mancha mangrove were collected at three locations, in three different climatic seasons, dry (May), rainy (October) and northern (November) (N = 9). VMA in the sediments was quantified using the Most Probable Number (MPN) technique with acetate and methanol as substrates. The influence of sulfate on methane production was analyzed from acetate in microcosm by gas chromatography and the chemical variables of salinity, pH, Eh, carbohydrates, organic content, and carbonates in the sediments were evaluated. Results: The abundance of VMA was 102 to 108 MPN/g of wet sediment, higher than that reported in other studies, this abundance was higher when methanol (104-108 MPN/g sediment) was used as substrate, compared to acetate (102-105 MPN/g sediment); methane production in the microcosms increased in sulfate-free conditions (29.78-929.75 nmol CH4/month) and in the sediments of the rainy season. Conclusion: The influence of the chemical conditions of the mangrove sediments on the methanogenic dynamics is highlighted, determining that in the rainy season, the decrease in salinity, more electronegative Eh, and the increase in organic fractions favored the methanogenesis.

Resumen Introducción. En agricultura orgánica, se utilizan abonos verdes y biocontroladores como métodos de fertilización y control de plagas. Sin embargo, la aplicación independiente de estos incrementa los costos de producción. Se propone una presentación peletizada que permita la aplicación conjunta de ambos insumos. Objetivo. Evaluar el efecto de Mucuna pruriens (L.) DC. peletizada e inoculada con Trichoderma harzianum Rifai en el aporte nutricional, el rendimiento agrícola y la regulación de Fusarium oxysporum f. sp. lycopersici en tomate (Solanum lycopersicum L.). Materiales y métodos. El experimento se ejecutó el año 2022 en Tablón del Guarco, Cartago, Costa Rica, bajo un diseño de bloques completos al azar con siete tratamientos y siete repeticiones. Se aplicaron dos formulaciones (A y B) de biopélet (M. pruriens + zeolita + T. harzianum) en tres dosificaciones (15, 30, 50 g/planta). La adición de T. harzianum se efectuó a razón de 5 g por cada kilo del biopélet. Se realizaron aplicaciones cada 15 días por tratamiento para un total de ocho aplicaciones. Se inoculó F. oxysporum (100 mL/planta con una concentración de 1 x 103 UFC) a la siembra. Resultados. La aplicación del biopélet mostró un rendimiento y peso de frutos de primera calidad similar al testigo comercial. En frutos de segunda y tercera calidad, no hubo diferencias significativas entre tratamientos. La eficiencia en el control de F. oxysporum alcanzó el 97,6 % con biopélet. Esta enmienda aumentó los niveles de Carbono, Nitrógeno y materia orgánica en el suelo e influenció el contenido nutricional en el follaje a los 60 días después de la siembra. Conclusiones. El biopélet tiene la capacidad de realizar aportes químicos y orgánicos al suelo, por lo cual mejora la nutrición del cultivo del tomate. Los resultados sugieren además que es una alternativa de biocontrol contra F. oxysporum y compatible con T. harzianum.

Abstract Introduction. In organic agriculture, green manures and biocontrols are used as methods for fertilization and pest control. However, their independent application of these inputs increases production costs. A pelletized formulation is proposed to allow simultaneous application of both inputs. Objective. To evaluate the effect of pelletized Mucuna pruriens (L.) DC. inoculated with Trichoderma harzianum Rifai on nutritional intake, agricultural yield, and regulation of Fusarium oxysporum f. sp. lycopersici in tomato (Solanum lycopersicum L.). Materials and methods. The experiment was carried out in 2022 in Tablón del Guarco, Cartago, Costa Rica, using a randomized complete block design with seven treatments and seven repetitions. Two formulations (A and B) of biopellet (M. pruriens + zeolite + T. harzianum) were applied at three dosages (15, 30, 50 g/plant). T. harzianum was added at a rate of 5 g/kg of biopellet. Applications of each treatment were conducted every 15 days for a total of eight applications. At the time of planting, F. oxysporum was inoculated (100 mL/plant with a concentration of 1 x 103 CFU). Results. The application of biopellet achieved a yield and weight of high-quality fruits similar to the commercial control. There were no significant differences among treatments for second and third-quality fruits. The technical efficiency in controlling F. oxysporum reached 97.6 % with biopellet. This amendment increased the levels of Carbon (C), Nitrogen (N), and organic matter in the soil and affected the nutritional content of the plant foliage in the first 60 days after sowing. Conclusions. The biopellet has the capacity to make chemical and organic contributions to the soil, which improves the nutrition of the tomato crop. It could be also a biocontrol alternative against F. oxysporum and compatible with T. harzianum.

Resumen Introducción. Suelos de baja fertilidad y altos costos de logística para la producción de plántulas caracterizan a la Amazonía peruana. Objetivo. Evaluar el efecto de la combinación de suelo arenoso y compost de palma aceitera sobre el sustrato, el crecimiento y la nutrición de plántulas de cacao en condiciones de invernadero. Materiales y métodos. El experimento se realizó durante 90 días en Yurimaguas, Loreto, bajo un diseño completamente al azar en una matriz de 5 × 5, con cinco dosis de compost de palma aceitera y suelo arenoso, a fin de obtener la mejor combinación para el crecimiento y la nutrición del cacao. Se midió la altura (cm), el diámetro (mm), el área foliar (cm2), el peso seco del vástago y la raíz; también se realizó análisis químico del suelo y análisis de plantas (macro y micronutrientes). Resultados. Los resultados mostraron que el suelo arenoso no tuvo un efecto significativo en las plántulas de cacao, mientras que los tratamientos con compost de palma aceitera promovieron la biomasa de brotes y raíces. Además, esta composta favoreció las condiciones para el crecimiento de las plántulas al promover mayor materia orgánica, fósforo disponible, calcio intercambiable, potasio y mayor capacidad de intercambio catiónico. En el caso de la nutrición del cacao, promovió una mayor absorción de macro y micronutrientes en las plántulas. Conclusiones. Estos resultados indicaron que el mejor tratamiento fue el compuesto exclusivamente por compost de palma aceitera, ya que promueve el crecimiento y la nutrición mediante la mejora de las condiciones del sustrato.

Abstract Introduction. Low-fertility soils and high logistics costs for seedling production characterize the Peruvian Amazon. Objective. To evaluate the effect of a combination of sandy soil and oil palm compost on substrate, growth, and nutrition of cocoa seedlings under greenhouse conditions. Materials and methods. The experiment was conducted for 90 days in Yurimaguas, Loreto, using a completely randomized design in a 5 × 5 matrix, with five doses of oil palm compost and sandy soil to determine the best combination for cocoa growth and nutrition. Height (cm), diameter (mm), leaf area (cm2), dry weight of stem and root were measured; soil chemical analysis and plant analysis (macro and micronutrients) were also conducted. Results. Sandy soil showed no significant effect on cocoa seedlings, while treatments with oil palm compost promoted shoot and root biomass. Additionally, this compost favored conditions for seedling growth by promoting higher organic matter, available phosphorus, exchangeable calcium, potassium, and higher cation exchange capacity. Regarding cocoa nutrition, it promoted greater absorption of macro and micronutrients in seedlings. Conclusions. These results indicate that the best treatment was the one composed entirely of oil palm compost, as it promotes growth and nutrition by improving substrate conditions.