Summary: Soil solution (SS) constitutes the volume from which plant roots extract dissolved nutrients. Despite its importance, the impact of its composition due to the application of organic amendments has been relatively little studied. The objective of this research was to study the impact of humic acids (HA) and chitosan (Cs) on the concentration of minerals in the SS, as well as their effect on the yield of the cabbage crop (Brassica oleracea L.). Under greenhouse conditions with calcareous soil, two doses of HA were applied (200 and 500 kg ha-1), as well as 50 and 150 kg ha-1 of Cs in a targeted manner. From the SS, 22 samples were taken non-destructively from the root zone once a week. The results of mineral content in the soil solution and mineral content on the biomass did not present significant differences, however, it was noted that the Cs50 treatment stimulated 41% higher plant biomass than the control (P ≤ 0.5, Tukey). It is concluded that Cs and HA do not significantly impact the ionic content of the SS or the mineral content of the biomass, although they do stimulate the yield.

Resumen: La solución del suelo (SS) constituye el volumen de donde las raíces de las plantas extraen los nutrientes disueltos. A pesar de su importancia, el impacto de su composición por la aplicación de enmiendas orgánicas se encuentra relativamente poco estudiado. El objetivo de esta investigación fue estudiar el impacto de los ácidos húmicos (AH) y quitosán (Cs) sobre la concentración de los minerales en la SS, así como su efecto en el rendimiento del cultivo de col (Brassica oleracea L.). En condiciones de invernadero con suelo calcáreo se aplicaron dos dosis de AH (200 y 500 kg ha-1), así como 50 y 150 kg ha-1 de Cs de forma dirigida. De la SS se tomaron 22 muestras en forma no destructiva de la zona de la raíz una vez por semana. Los resultados del contenido mineral en la solución del suelo y del contenido mineral en la biomasa no presentaron diferencias significativas, no obstante, se apreció que el tratamiento Cs50 estimuló 41% la biomasa vegetal superior al testigo (P ≤ 0.5, Tukey). Se concluye que el Cs y AH no impactan significativamente el contenido iónico de la SS ni el contenido mineral de la biomasa, aunque si estimulan el rendimiento.

ABSTRACT Alternative techniques for cultivation without soil are widespread; however, studies comparing hydroponic systems still need to be studied, mainly in semi-arid regions. The present study aimed to evaluate the effect of hydroponic systems on the yield and quality of lettuce cultivars subjected to different electrical conductivities of the nutrient solution. The research was conducted in a greenhouse, adopting a completely randomized design in a 2 × 2 × 3 factorial scheme, being two lettuce cultivars (Cinderela and Rubinela), two electrical conductivities (2.90 and 1.6 dS m-1), and three hydroponics systems (NFT, semi-hydroponic, and floating), with three replications. The number of leaves, leaf succulence, specific leaf area, leaf fresh mass, total dry mass, leaf area, titratable acidity, vitamin C, and soluble solids were evaluated. Cinderela cultivar showed the highest average leaf fresh mass, total dry mass, leaf area, and vitamin C values. The NFT and floating systems provided the highest leaf yield and quality, especially in the solution of 1.60 dS m-1. The semi-hydroponic system provided greater development of the plants with a more concentrated nutrient solution (2.90 dS m-1). widespread however studied semiarid semi arid regions greenhouse scheme Rubinela, Rubinela , Rubinela) 2.90 290 90 (2.9 16 1 6 1. m1, m1 m m-1) NFT, (NFT semihydroponic, semihydroponic hydroponic, floating, floating) replications leaves succulence area mass acidity evaluated values 160 60 m1. m-1 . 2.9 29 9 (2. m- 2. (2 (

RESUMO Técnicas alternativas de cultivo sem solo são difundidas; no entanto, estudos comparando os sistemas hidropônicos ainda precisam ser estudados, principalmente em regiões semiáridas. O presente estudo teve como objetivo avaliar a efeito de sistemas hidropônicos na produtividade e qualidade de cultivares de alface submetidas a diferentes condutividades elétricas da solução nutritiva. A pesquisa foi conduzida em casa de vegetação, adotando delineamento inteiramente casualizado. em esquema fatorial 2 × 2 × 3, sendo duas cultivares de alface (Cinderela e Rubinela), duas condutividades elétricas (2,90 e 1,6 dS m-1), e três sistemas hidropônicos (NFT, semi-hidropônico e floating), com três repetições. Foram avaliados número de folhas, suculência foliar, área foliar específica, massa fresca foliar, massa seca total, área foliar, acidez titulável, vitamina C e sólidos solúveis. A cultivar Cinderela apresentou maior massa fresca de folhas, massa seca total, área foliar, acidez titulável e vitamina C e sólidos solúveis. Os sistemas NFT e floating proporcionaram maior produtividade e qualidade foliar, especialmente na solução de 1,60 dS m-1. O sistema semi-hidropônico proporcionou maior desenvolvimento das plantas com solução nutritiva mais concentrada (2,90 dS m-1). difundidas entanto estudados semiáridas vegetação casualizado 3 Rubinela, Rubinela , Rubinela) 2,90 290 90 (2,9 16 1 6 1, m1, m1 m m-1) NFT, (NFT semihidropônico semi hidropônico floating, floating) repetições folhas específica total solúveis 160 60 m1. 1. m-1 . 2,9 29 9 (2, m- 2, (2 (

ABSTRACT Degraded peat has a high potential for use in agricultural production, especially food crops. The water table, which impacts the production of greenhouse gases (GHGs), is the main problem concerning peat utilization. The study aimed to determine the production of greenhouse gases at various peat water levels. The study was conducted in a laboratory setting utilizing the soil column of undisturbed peat soil. The factorial experiment was arranged in randomized block design, with three replicates, with the first factor was peat cropping use: Maize (Zea mays L.), pineapple (Ananas comosus (L.) Merr.), and scrubs. The second factor was water level (0, 10, 20, 30 cm depth). Variables measured were GHG flux (CO2 and CH4), pH, redox potential, total C content, and ash content. The peat cropping use interacted significantly with the peat water level on the potential for CH4 and CO2 production and the value of global warming potential. Water table depth significantly increased CO2 flux and global warming potential (GWP) in all three peat cropping uses. The lowest GWP at a 0 cm peat water level was 944 (pineapple use), 961 (maize use), and 1097 mg CO2e m-2 d-1 (scrub use). Peat for pineapple cultivation produces the lowest CO2 production and GWP compared to maize cultivation and scrubs. The negative relationship between redox potential and GWP is significant in peat for scrub. The relationship between pH and GWP is significant in peat for pineapple and scrub.

Abstract This paper examines the heterogeneity in the environmental field, specifically in the emission of the main of the greenhouse gases, CO2, within the 3 countries composing the North American region. On the one hand, the United States is a large emitter of CO2 (19% of global emissions accumulated in 1990-2020), only surpassed by China as of 2005. On the other hand, Canada and Mexico are relatively small emitters on a global scale (1.8% and 1.4% of global emissions accumulated in 1990-2020, respectively), but with large economic and technological differences. Under these conditions, the objective of this research is to find differences and similarities between the three countries regarding CO2 emissions trends and their driving structural factors: scale, technological and composition effects, based on annual data from 2001 to 2014. With a structural decomposition analysis, we found that, in general, the scale effect was polluting and dominating in the period, while the technological effect was anti-polluting, in addition to a small and ambivalent composition effect (positive in some years and negative in others). It is concluded that there is a process of convergence in the intensity of emissions per GDP value and with respect to the three mentioned effects. It is also concluded that the characteristics of the three effects in Mexico were like those of the United States, while Canada approached along the analysis period.

Resumen Este artículo examina la heterogeneidad, en el ámbito ambiental, de los 3 países que componen la región de Norteamérica, específicamente en la emisión de CO2, el principal gas efecto invernadero. Por un lado, Estados Unidos es un gran emisor de CO2 (19% de las emisiones globales acumuladas en 1990-2020), solamente superado por China a partir de 2005. Por otro lado, Canadá y México son emisores relativamente pequeños a escala global (respectivamente 1.8% y 1.4% de las emisiones globales acumuladas en 1990-2020), pero con grandes diferencias económicas y tecnológicas. En estas condiciones, el objetivo de la investigación es encontrar diferencias y similitudes entre los tres países respecto de las tendencias de emisiones de CO2 y sus factores estructurales conductores: los efectos escala, tecnológico y composición, con base en datos anuales de 2001 a 2014. Con un análisis de descomposición estructural, se encontró que, en general, el efecto escala fue contaminante y dominó en el periodo, mientras que el efecto tecnológico resultó anticontaminante, además de un efecto composición pequeño y ambivalente (positivo en unos años y negativo en otros). Se concluye que hay un proceso de convergencia en la intensidad de emisiones por valor del PIB y respecto de los tres efectos mencionados. También se concluye que las características de los tres efectos en México fueron parecidas a las de Estados Unidos, a las cuales Canadá se aproximó durante el periodo de análisis.

ABSTRACT Achieving the optimal energy balance in hydroponic greenhouses is a critical challenge in modern agriculture. This involves managing energy resources to create an environment conducive to robust crop growth. Researchers are exploring advanced thermal models and innovative technologies to enhance energy efficiency and establish a harmonious equilibrium in these controlled environments. Various studies have addressed the optimization of energy consumption in hydroponic greenhouses, with a focus on the greenhouse covering materials and real-time energy monitoring. This study aims to enhance the conventional model by optimizing the form and cover material of the greenhouse and considering new heat gain and loss parameters, including the direct and indirect lighting effect. This study demonstrates that the emitted light and energy consumption of the lighting system directly influence the energy balance. This innovative approach refines the understanding of the interplay between lighting systems and energy consumption, leading to more efficient and sustainable hydroponic greenhouse practices. Collectively, the contributions of esteemed researchers have significantly enriched the understanding of energy consumption dynamics in hydroponic greenhouse environments, setting new standards for energy efficiency, sustainability, and productivity in hydroponic agriculture. agriculture growth environments realtime real time monitoring parameters effect practices Collectively sustainability

RESUMO Conseguir um equilíbrio energético ótimo em estufas hidropônicas é um desafio crítico na agricultura moderna. Isto implica a gestão dos recursos energéticos para criar um ambiente propício a um crescimento robusto das culturas. Os pesquisadores estão a explorar modelos térmicos avançados e tecnologias inovadoras para melhorar a eficiência energética e estabelecer um equilíbrio harmonioso nestes ambientes controlados. Vários estudos abordaram a otimização do consumo de energia em estufas hidropônicas, com destaque para os materiais de cobertura das estufas e a monitorização da energia em tempo real. Este estudo visa melhorar o modelo convencional, otimizando a forma e o material de cobertura da estufa e considerando novos parâmetros de ganho e perda de calor, incluindo o efeito da iluminação direta e indireta. Este estudo demonstra que a luz emitida e o consumo de energia do sistema de iluminação influenciam diretamente o balanço energético. Esta abordagem inovadora melhora a compreensão da interação entre os sistemas de iluminação e o consumo de energia, conduzindo a práticas de estufa hidropônica mais eficientes e sustentáveis. Coletivamente, as contribuições de pesquisadores conceituados enriqueceram significativamente a compreensão da dinâmica do consumo de energia em ambientes de estufa hidropônica, estabelecendo novos padrões de eficiência energética, sustentabilidade e produtividade na agricultura hidropônica. moderna culturas controlados real convencional calor indireta sustentáveis Coletivamente

Abstract Introduction. Nitrogen (N) is an essential element for the photosynthesis process, and therefore, a determining factor in yield. The use of optical sensors to determine transmittance indices (SPAD, CCI), reflectance (NDVI) and fluorescence (Fv.Fm -1) related to the state of foliar N, allows adequate management based on non-destructive "in situ" monitoring. Objective. To evaluate the effect of different fertigation management strategies on nitrogen and chlorophyll concentration in the leaf; and the relationship between i- N and Cl concentration in leaf, ii- N and Cl concentration in leaf with yield and iii- N and Cl concentration in leaf with SPAD, CCI, NDVI and Fv.Fm -1 indices. Materials and methods. Six treatments were evaluated in an unrestricted randomized design with a 2 x 3 factorial arrangement, which combined 2 irrigation strategies (E1: low volume and more frequent and E2: high volume and less frequent) and 3 levels of nutrition: low (NB), medium (NM) and high (NA). The direct measurements of N and Cl in the leaf were determined with the Kjeldahl method and by ethanol extraction, respectively. Results. Nutrition level affected N content, where the NM and NA treatments were similar, although higher than NB. The regression model showed little ability to estimate N and yield from the Cl content in the leaf. Estimation of Cl in the leaf from the CCI (R2: 0.71) and SPAD (R2: 0.75) indices were only promising in NB. To estimate foliar N, the regression with Fv.Fm -1 showed R2 values of 0.89 in NB and 0.69 in NM; while for NDVI the R2 values were 0.61 in NB and 0.47 in NM. Conclusion. SPAD, CCI, NDVI and Fv.Fm -1 indices showed potential to estimate chlorophyll and N concentration in the leaf with low and medium nutrient inputs, and with limitations in treatments with high nutrient inputs.

Resumen Introducción. El nitrógeno (N) es un elemento esencial para el proceso de fotosíntesis, y por tanto, determinante en el rendimiento. El uso de sensores ópticos para determinar índices de transmitancia (SPAD, CCI), reflectancia (NDVI) y fluorescencia (Fv.Fm -1) relacionados con el estado del N foliar, permite un adecuado manejo a partir del monitoreo “in situ” no destructivo. Objetivo. Evaluar el efecto de diferentes estrategias de manejo del fertiriego sobre las concentraciones de nitrógeno y clorofila en hoja; y la relación entre i- concentración de N y de clorofila (Cl) en hoja, ii- concentración de N y de Cl en hoja con el rendimiento y iii- concentración de N y de Cl en hoja con índices SPAD, CCI, NDVI y Fv.Fm -1. Materiales y métodos. Se evaluaron 6 tratamientos en un diseño irrestricto al azar con arreglo factorial 2 x 3, que combinaron 2 estrategias de riego (E1: bajo volumen y de mayor frecuencia y E2: alto volumen y menor frecuencia) y 3 niveles de nutrición: bajo (NB), medio (NM) y alto (NA). Las medidas directas de N y Cl en hoja se determinaron con el método Kjeldahl y por extracción con etanol, respectivamente. Resultados. El nivel de nutrición afectó el contenido de N, donde los tratamientos NM y NA fueron similares, aunque superiores a NB. El modelo de regresión mostró poca capacidad para estimar N y rendimiento a partir del contenido de Cl en hoja. La estimación de Cl en hoja a partir de los índices CCI (R2: 0,71) y SPAD (R2: 0,75) resultaron prometedores solamente en NB. Para estimar N foliar, la regresión con Fv.Fm -1 mostró valores de R2 de 0,89 en NB y 0,69 en NM; mientras que para NDVI los valores R2 fueron 0,61 en NB y 0,47 en NM. Conclusión. Los índices SPAD, CCI, NDVI y Fv.Fm -1 presentaron potencial para estimar la concentración de clorofila y de N en hoja con aportes bajo y medio de nutrientes, y con limitaciones en los tratamientos con altos aportes de nutrición.

Abstract Introduction. The amount of usable water is currently limited due to the deterioration of its sources and indiscriminate use. An alternative to this problem is producing under green houses, where it is possible to obtain better water use efficiency (WUE) by reducing crop evapotranspiration (ETc) without compromising its productive potential. Objective. To evaluate the effect of 3 levels of volumetric moisture content depletion in coir on the vegetative-generative behavior of hydroponic tomato and sweet pepper produced under greenhouse cultivation. Materials and methods. The study was conducted during August to December 2020 and January 2021, at Estación Experimental Agrícola Fabio Baudrit Moreno, Alajuela, Costa Rica. Three treatments were applied: 11, 22 and 32% of water depletion in the substrate. Morphophysiological and reproductive parameters such as: the leaf area (AF), the number of leaves (NH), width (AH) and length of the leaf (LH), the length (LT) and the diameter of the stem (DT), the number of nodes (NN), dry matter (DM), stomatal conductance (gs), crop evapotranspiration (ETc), water use efficiency (WUE), the total yield (Rt), the commercial (Rc) of first (F1), second (F2) and third (F3) and waste fruits (Fd) were evaluated. Results. In the tomato treatments (TT) there was no effect on NH, LT, LH and NN; on the other hand, differences were reported in AH, DT and in MS, with treatment TT11 obtaining the higher values. The sweet pepper (TC), the treatment TC11 was statistically superior to the other treatments in number (NH), width (AH) and length (LH) of the leaf, in number of nodes (NN), production of fresh (MF) and dry matter (MS) and in diameter of the stem (DT), while there were no differences between treatments in stem length (LT). There were no differences in ETc and Rt, for both crops, but there was a difference in the commercial yield once it was divided by quality of fruit, TT11 presented the highest production of first and second fruit quality, while treatment TC11 presented the highest production of first, second and third fruit quality. For both crops, there were significant differences between treatments in terms of stomatal conductance. TT11 and TC11 treatments obtained the highest value of EUA with 37.32 kg.m-3 and 21.46 kg.m-3, respectively. Conclusion. In both crops, treatments with 11 and 22% water depletion showed an adequate balance between vegetative and productive growth, which was reflected in greater production of better quality commercial fruits, less waste and greater WUE.

Resumen Introducción. El uso de agua dulce en agricultura se encuentra limitado debido al deterioro de sus fuentes y su uso indiscriminado. El riego deficitario en agricultura protegida es una alternativa para mejorar la eficiencia en el uso del agua, a través de la reducción de la evapotranspiración del cultivo, sin comprometer su potencial productivo. Objetivo. Evaluar el efecto de 3 niveles de agotamiento del contenido de humedad volumétrica en un sustrato de fibra de coco, sobre el comportamiento vegetativo-generativo de los cultivos de tomate y chile dulce hidropónicos en invernadero. Materiales y métodos. El estudio se realizó en la Estación Experimental Agrícola Fabio Baudrit Moreno, Alajuela, Costa Rica. En ambos cultivos se aplicaron 3 tratamientos con 11, 22 y 32% de agotamiento hídrico en el sustrato, en un diseño experimental en bloques completos al azar. Se evaluaron parámetros morfofisiológicos y productivos tales como área foliar (AF), número de hojas (NH), ancho (AH) y longitud de hoja (LH), longitud (LT) y diámetro del tallo (DT), número de nudos (NN), materia seca (MS), conductancia estomática (gs), evapotranspiración del cultivo (ETc), eficiencia de uso de agua (EUA), rendimiento de fruto comercial (Rc) de primera (F1), segunda (F2) y tercera (F3), fruto de desecho (Fd) y rendimiento total (Rt). Resultados. En los tratamientos en tomate (TT) no hubo efecto sobre el NH, LH, LT y NN; mientras que con TT11 se obtuvieron valores superiores en AH, DT y MS. En chile dulce (TC), el TC11 obtuvo mayor NH, AH, LH, NN, DT y MS que los demás tratamientos; mientras que no hubo diferencias entre tratamientos en LT. En ambos cultivos, no hubo efecto sobre la ETc y el Rt, sin embargo, con 11% de agotamiento se obtuvo mayor producción comercial de F1 y F2 por lo que consecuentemente hubo mayor EUA con 37,32 kg.m-3 y 21,46 kg.m-3, respectivamente. Para ambos cultivos, la gs fue diferente entre tratamientos. Conclusión. En ambos cultivos, los tratamientos con 11 y 22% de agotamiento hídrico evidenciaron un adecuado balance entre crecimiento vegetativo y productivo, que se reflejó en mayor producción de frutos comerciales de mejor calidad, menos desecho y mayor EUA.

Abstract Introduction.Soybean establishes a symbiosis with Bradyrhizobium japonicum that allows it to fix atmospheric N. Coinoculation with other plant growth-promoting microorganisms can increase Biological Nitrogen Fixation (BNF) and plant growth. Objective. Determine if inoculation with P-solubilizing fungi (SP), Aspergillus flavus (S1) and Trichoderma longibrachiatum (S2), affects growth and BNF variables in soybeans. Materials and methods. In the greenhouse on an Andisol and an Ultisol, growth variables and BNF were evaluated in soybeans inoculated with B. japonicum and 2 SPs. Five treatments were evaluated: an absolute control (T), addition of phosphate rock (RF), addition of RF and inoculation with B. japonicum (BRF) and the addition of RF, B. japonicum and the 2 SPs independently (BRFS1 and BRFS2). An unrestricted randomized design with 4 repetitions was established and the data was analyzed according to normality, either with ANDEVA and DGC at 5% or Kruskal Wallis at 5%. Results. The responses obtained showed a positive effect on the evaluated variables when soybeans were inoculated with SP in addition with B. japonicum. The effect was a trend in Andisol, for the variables aerial fresh weight and number of nodules and their dry weight, while for Ultisol significance was found for these same variables, as well as for aerial dry weight, leaf area and N content and foliar P, with the greatest effect in BRFS2. In absolute terms, the highest P content in the soil microbial biomass and the highest SP population was found in the treatment with the presence of S2. The populations of N Fixers (NF) in the soil were higher for T and RF that did not have inoculation with B. japonicum. Conclusion. Inoculation with SP fungi can positively affect BNF, foliar N and P amounts as well as soybean plant growth.

Resumen Introducción. La soya establece una simbiosis con Bradyrhizobium japonicum para fijar N atmosférico. La coinoculación con otros microorganismos promotores del crecimiento (MPC) puede incrementar la Fijación Biológica de Nitrógeno (FBN) y el crecimiento de las plantas. Objetivo. Determinar si la inoculación con los hongos solubilizadores de P (SP), Aspergillus flavus (S1) y Trichoderma longibrachiatum (S2), afecta variables de crecimiento y de FBN en soya. Materiales y métodos. En un Andisol y un Ultisol en invernadero, se evaluaron variables de crecimiento y FBN en soya inoculada con B. japonicum y 2 SP. Se evaluaron 5 tratamientos: un testigo absoluto (T), adición de roca fosfórica (RF), adición de RF e inoculación con B. japonicum (BRF) y la adición de RF, B. japonicum y los 2 SP de manera independiente (BRFS1 y BRFS2). Se estableció un diseño irrestricto al azar con 4 repeticiones y los datos se analizaron según la normalidad, con ANDEVA y DGC al 5% o Kruskal Wallis al 5%. Resultados. Se obtuvo un efecto positivo sobre las variables evaluadas, cuando la soya se inoculó con los SP además de B. japonicum. El efecto fue tendencia en el Andisol, para las variables peso fresco aéreo y número de nódulos y su peso seco, mientras que para el Ultisol se encontró significancia para estas mismas variables, así como para el peso seco aéreo, área foliar y contenido de N y P foliar, el efecto fue mayor en BRFS2. En términos absolutos el mayor contenido de P en la biomasa microbiana del suelo y la mayor población de SP se encontró en el tratamiento con la presencia de S2. Las poblaciones de Fijadores de N fueron mayores para T y RF. Conclusión. La inoculación con hongos SP puede afectar positivamente la FBN, las cantidades de N y P foliar así como el crecimiento de las plantas de soya.

Resumen Las dosis de paclobutrazol que reducen la altura del tallo floral o modifican el aspecto visual pueden ser distintas para cada cultivar. En esta investigación se evaluó el efecto de ocho concentraciones de paclobutrazol en la altura del tallo, aspecto visual, periodo de antesis y distribución de biomasa de Lilium asiático cv. Litouwen. Dieciocho bulbos fueron sumergidos por 24 h en 5 L de las siguientes soluciones: 0 (control), 2.5, 5, 10, 20, 40, 100, 200 mg L-1 de paclobutrazol. Transcurrido el tiempo, tres bulbos se plantaron en macetas con 2.5 L de tezontle y se distribuyeron al azar en el interior de un invernadero. Durante el ciclo del cultivo, de 2022, la humedad del sustrato se mantuvo con solución Steiner. Los resultados se procesaron con análisis de varianza y pruebas de comparación de medias (Tukey, p≤ 0.05). La altura de los tallos florales fue de 61.5, 56.6, 43.4, 29.1, 18.4 y 14.1 cm con 0 o 2.5, 5 o 10, 20, 40, 100 y 200 mg L-1 de paclobutrazol respectivamente. El número de hojas y el área foliar disminuyeron, pero el diámetro del tallo, índice de verdor, biomasa seca de raíces, botones florales, tiempo a la floración y periodo de antesis se incrementaron a partir de 40 mg L-1. En Lilium ‘Litouwen’ se requieren dosis de 40 o 100 mg L-1 de paclobutrazol para obtener plantas compactas con follaje verde intenso y botones florales llamativos, lo que ayudaría a su comercialización como plantas de maceta.

Abstract The doses of paclobutrazol that reduce the height of the flower stem or modify the visual appearance may be different for each cultivar. In this research, the effect of eight paclobutrazol concentrations on stem height, visual appearance, anthesis period, and biomass distribution of Asiatic Lilium cv. Litouwen was evaluated. Eighteen bulbs were immersed for 24 h in 5 L of the following solutions: 0 (control), 2.5, 5, 10, 20, 40, 100, 200 mg L-1 of paclobutrazol. After some time, three bulbs were planted in pots with 2.5 L of tezontle and randomly distributed inside a greenhouse. During the 2022 crop cycle, the moisture of the substrate was maintained with a Steiner solution. Results were processed with analysis of variance and Tukey’s mean comparison tests (p≤ 0.05). The height of the flower stems was 61.5, 56.6, 43.4, 29.1, 18.4, and 14.1 cm with 0 or 2.5, 5 or 10, 20, 40, 100, and 200 mg L-1 of paclobutrazol, respectively. Leaf number and leaf area decreased, but stem diameter, greenness index, dry root biomass, flower buds, time to flowering and anthesis period increased from 40 mg L-1. In Lilium ‘Litouwen’, doses of 40 or 100 mg L-1 of paclobutrazol are required to obtain compact plants with intense green foliage and striking flower buds, which would help their marketing as pot plants.

Resumen: El nitrógeno en el suelo es crucial para la agricultura, pero a menudo es limitante, afectando el rendimiento de los cultivos. La deficiencia requiere fertilizantes sintéticos, pero su uso inadecuado causa daños ambientales y costos elevados. Las bacterias del género Rhizobium, simbiontes de leguminosas, ofrecen una solución al fijar nitrógeno de manera sostenible, reduciendo la dependencia de fertilizantes. Esta investigación determinó el número más probable (NMP) de células de Rhizobium spp. procedente de dos biofertilizantes comerciales de origen ecuatoriano y mexicano en condiciones de invernadero. Para esto, se realizó la inoculación directa con disoluciones seriadas (10-1 a 10-10) en macetas con pomina esterilizada al vapor, donde se germinaron plantas de frijol ejotero (Phaseolus vulgaris L.) de la variedad Blue Lake. A los 45 días después de siembra (DDS) se evaluaron los siguientes indicadores morfológicos: área foliar, peso de la planta en húmedo, altura de planta y número de flores, determinándose diferencias estadísticas entre el tipo de biofertilizante y la concentración de cada dilución. El experimento se adecuó a un diseño de bloques completos al azar con arreglo de parcela dividida con tres repeticiones por dilución, en consideración de las fluctuaciones de temperatura presentes en la zona de estudio. El NMP, al 95% de confianza, fue de 4,45x107 rizobios g-1 de pomina en una dilución 10-5 para el biofertilizante mexicano, y 1,48x105 rizobios g-1 de pomina en una dilución 10-4 para el biofertilizante ecuatoriano. La dilución óptima estimada para ambos productos fue de 10-8.

Abstract: Soil nitrogen is crucial for agriculture, but it is often limited, affecting crop yields. Deficiency requires synthetic fertilizers, but their improper use results in environmental damage and high costs. Bacteria of the genus Rhizobium, symbionts of legumes, offer a sustainable solution by fixing nitrogen, thus reducing dependence on fertilizers. This research determined the most probable number (MPN) of cells of Rhizobium spp. from two commercial biofertilizers of Ecuadorian and Mexican origin under greenhouse conditions. For this, direct inoculation with serial dilutions (10-1 to 10-10) was performed in pots with steam-sterilized pumice where Blue Lake variety snap bean (Phaseolus vulgaris L.) plants were germinated. The following morphological indicators were evaluated at 45 days after sowing (DAS): leaf area, plant wet weight, plant height, and number of flowers, determining statistical differences between the type of biofertilizer and the concentration of each dilution. The experiment followed a randomized complete block design with a split-plot arrangement, with three replicates per dilution, considering temperature fluctuations in the study area. The MPN at 95% confidence was 4.45x107 rhizobia g-1 of pumice at a 10-5 dilution for the Mexican biofertilizer, and 1.48x105 rhizobia g-1 of pumice at a 10-4 dilution for the Ecuadorian biofertilizer. The estimated optimal dilution for both products was 10-8.

Resumen El aporte de nutrimentos al cultivo de maíz en México es principalmente con fertilizantes químicos, sin embargo, el precio de estos insumos requiere buscar otras alternativas para abatir los costos, sin disminuir la producción. El objetivo de este trabajo fue determinar el efecto individual y combinado de Azospirillum brasilense, Bacillus subtilis y Serendipita indica (ocho tratamientos) en la producción de maíz. El cultivo se estableció en Cieneguillas, Zacatecas, en condiciones de invernadero, en el año 2022. La inoculación de los microorganismos se realizó al momento de la siembra. Los ocho tratamientos con los microorganismos se evaluaron en un diseño experimental en bloques al azar con cuatro repeticiones. Con la co-inoculación de A. brasilense + S. indica se incrementó el rendimiento de toda la planta y el mayor rendimiento de grano con A. brasilense + B. subtilis, este último incremento, respecto al testigo, fue de 40%.

Abstract In Mexico, the nutrients to the corn crop are supplied with chemical fertilizers, however, the price of these inputs requires looking for other alternatives to reduce costs, without reducing production. The objective of this work was to determine the individual and combined effect of Azospirillum brasilense, Bacillus subtilis, and Serendipita indica, (eight treatments) on corn production. The crop was established in Zacatecas, Mexico, under greenhouse conditions, in the year 2022. The microorganism's inoculation was carried out at the sowing time. The eight treatments with microorganisms were evaluated in an experimental design in randomized blocks with four repetitions. With the co-inoculation of A. brasilense and S. indica the yield of the entire plant was increased, and the highest grain yield with A. brasilense and B. subtilis, this last increased, compared with the control treatment, it was 40%.

RESUMEN El presente estudio analiza el impacto del desarrollo financiero sobre las emisiones de gas de efecto invernadero en países en desarrollo, considerando los efectos de derrame debidos al consumo de energía. Para tal propósito, utilizamos modelos de regresión de panel dinámico con umbral. La evidencia que obtuvimos con datos para el periodo 2003-2009 muestra que el desarrollo financiero tiene un efecto de umbral significativo en las emisiones. La forma en que opera este efecto depende de la distinción entre instituciones financieras y mercados financieros. En contraste con el desarrollo del mercado financiero, se ha observado que en países donde el índice de desarrollo de las instituciones financieras es mayor que 0.356, las fuerzas que incrementan las emisiones se debilitan.

ABSTRACT This study aims to analyze the impact of financial development on greenhouse gas emissions in the case of developing countries, considering the spillover effects due to energy consumption. For this purpose, static and dynamic panel threshold regression models were used. The evidence obtained from the 2003-2019 period data shows that financial development has a significant threshold effect on emissions. How this effect works depends on the distinction between financial institutions and financial markets. In contrast to financial market development, in countries where the financial institution development index is above 0.356, the forces that increase emissions have been observed to weaken.

Abstract The wilt or damping-off of husk tomato is a disease caused by fungi originating in the soil, among which Fusarium oxysporum, Macrophomina phaseolina, and Rhizoctonia solani stand out, causing losses due to the lack of resistant varieties. This study aimed to determine the response of husk tomato (Physalis ixocarpa Brot.), Dalí, Siqueiros, and Tamayo hybrids, as well as cv. Gabriela, Puebla, San Miguel, and Tecozautla, to pathogenic isolates of F. oxysporum, M. phaseolina, and R. solani. The study was conducted under greenhouse conditions; sterilized substrate of river sand + peat (1:3 v/v) was placed in pots and then inoculated with three isolates of F. oxysporum 1.6x105 CFU, two of M. phaseolina, and three of R. solani (8 g of infested sorghum seed/pot, of each fungus). Five seeds of the corresponding husk tomato cultivar were deposited in each pot, then covered with the same substrate and incubated for 30 days. A completely randomized design was used, with three repetitions (pots). In the control treatment, the seeds were sown on soil without fungus. The emergence of seedlings was estimated nine days after sowing (das), and the severity of infection for each of the pathogens (scale of 0-5) at 30 das. Data were analyzed using nonparametric statistics. The seven cultivars tested were susceptible to the species F. oxysporum, M. phaseolina, and R. solani; some of the isolates tested exerted a significant differential effect of virulence on some of the varieties studied.

Resumen La marchitez o secadera del tomatillo es una enfermedad causada por hongos con origen en el suelo, entre los que destacan Fusarium oxysporum, Macrophomina phaseolina y Rhizoctonia solani, causando pérdidas por la carencia de variedades resistentes. El objetivo de este estudio fue determinar la respuesta del tomatillo (Physalis ixocarpa Brot.), híbridos Dalí, Siqueiros y Tamayo, así como los cv. Gabriela, Puebla, San Miguel y Tecozautla, hacia aislados patogénicos de F. oxysporum, M. phaseolina y R. solani. El estudio se realizó bajo condiciones de invernadero, en macetas se colocó arena de río + sustrato de turba (1:3 v/v) esterilizado y después se inoculó, con tres aislados de F. oxysporum 1.6x105 UFC, dos de M. paseolina y tres de R. solani (8 g de semilla de sorgo infestada/maceta, de cada hongo). En cada maceta se depositaron cinco semillas del cultivar de tomatillo correspondiente, luego se taparon con el mismo sustrato e incubaron por 30 días. Se utilizó un diseño completo al azar, con tres repeticiones (macetas). En el tratamiento testigo las semillas se sembraron sobre suelo sin hongo. A los nueve días después de la siembra (dds) se estimó la emergencia de plántulas, 30 dds, la severidad de la infección de por cada uno de los patógenos (escala de 0-5). Los datos se analizaron mediante estadística no paramétrica. Los siete cultivares probados fueron susceptibles a las especies F. oxysporum, M. phaseolina y R. solani, algunos de los aislados probados ejercieron un efecto significativo diferencial de virulencia, en algunas de las variedades estudiadas.

ABSTRACT Integrated management is considered the best strategy to mitigate the damage caused by plant-parasitic nematodes. However, there is still limited information regarding some integrated techniques. Thus, this study aimed to assess the effects of genetic management associated with chemical control of Meloidogyne javanica in soybean (Glycine max (L.) Merr.) The experiment was installed in a greenhouse according to an 8×4 factorial design with eight replicates. The first factor was soybean cultivar (HO Juruena IPRO, resistant; Foco IPRO, HO Maracaí IPRO, and CZ 58B28 IPRO, moderately resistant; HO Mamoré IPRO, moderately susceptible; and Extrema IPRO, CZ 48B32 IPRO, and HO Aporé IPRO, susceptible). The second factor consisted of an untreated control and commercial nematicides based on abamectin, thiodicarb+imidacloprid, and fluopyram. Plants were inoculated with 2000 nematode eggs, and nematode and vegetative variables were evaluated at 65 d after inoculation. There was an interaction effect on nematode variables. Furthermore, there was an additive effect of genetic management and chemical control, mainly in resistant cultivars treated with thiodicarb+imidacloprid or fluopyram with controls of up to 69.90% and 96.86%, respectively. The application of fluopyram and the use of ‘HO Juruena IPRO’, ‘Foco IPRO’, or ‘HO Maracaí IPRO’ also contributed to the control of M. javanica. Vegetative variables were studied by analyzing product effects separately, but results were inconclusive.

ABSTRACT Soil ameliorants play a crucial role in enhancing soil fertility and rice (Oryza sativa L.) production in acid-sulfate soils. This research aims to study the impact of Si-humic ameliorants on soil chemical properties, plant growth, Fe levels, and rice production in acid-sulfate soil. The experiments were conducted at the Laboratory and Greenhouse of the Indonesia Swampland Agricultural Research Institute. The greenhouse experiment adopted a factorial RCBD with Factor 1 representing the ameliorant formula type: 100% lime (F0), 30% commercial humate+30% rice husk ash+40% lime (F1), 30% water hyacinth humate+0% rice husk ash+40% lime (F2), 30% water hyacinth humate+30% rice husk biochar+40% lime (F3), 30% commercial humate+30% rice husk biochar+40% lime (F4), and control without ameliorant. Factor 2 represents dosage of soil ameliorant: 0, 1, 2, and 4 t ha-1. Observations included soil properties such as pH, exchangeable Fe, available P, plant growth, Fe toxicity, yield, and yield components. Silicon-humic soil ameliorant demonstrated the ability to enhance soil pH from 3.16 to 3.63, available P from 6.12 to 30.16 mg kg-1, and decrease Fe 690 to 371 mg kg-1. Specifically, the F3 Si-humate formulation alleviated Fe toxicity, enhanced P availability, promoted rice growth, and improved yield. The application of 4 t ha-1 Si-humate F3 had the best effect in increasing grain yield by 4.22 g pot-1 compared to the control. The application of Si-humate F3 not only improved soil quality and increased rice yields but also reduced the need for lime, contributing to the potential maintenance of soil health.