Abstract Proper nutritional management is crucial for the development and production of cannabinoids in the cultivation of Cannabis sativa var. Cherry Oregon. The objective of this research was to evaluate the effect of five concentrations of Steiner nutrient solution on the phenology of medicinal hemp, and to determine the optimal dosage of the nutrient solution for cannabinoid content (cannabidiol [CBD] and tetrahydrocannabinol [THC]). Research was conducted at the Instituto Nacional de Investigaciones Agropecuarias [INIAP], Estación Experimental Santa Catalina [EESC], in Ecuador, under greenhouse conditions. Five concentrations of Steiner nutrient solution (50, 75, 100, 125 and 150%). Agronomic variables such as plant height, diameter at collar height, yield, and cannabinoid content in flowers were evaluated. Significant effects (p > 0,05) were used. Agronomic variables such as plant height, diameter at neck height, yield, and cannabinoid content in flowers were evaluated. Significant effects (p > 0.05) were observed in plant height and diameter at neck height. Tetrahydrocannabinol (THC) remained at concentrations lower than 1%. Concentrations at 75% and 100% of the nutrient solution showed higher levels of cannabidiol (CBD) with 15,3% and 15,15%, respectively. The nutrient solution at 125% and 100% concentrations promoted greater growth in plant height and diameter. The 125% concentration also produced the highest dry biomass yield with 810 g m-2 or 8,1 t ha-1, surpassing the other concentrations. It is concluded that the optimal concentration of Steiner solution was 125% for accumulation of dry biomass, and 75 and 100% for cannabinoid production in flowers (CBD), complying with current regulations (< 1% THC).

Resumen El adecuado manejo nutricional es crucial para el desarrollo y producción de cannabinoides en el cultivo de Cannabis sativa var. Cherry Oregon. Esta investigación tuvo por objetivo evaluar el efecto de cinco concentraciones de solución nutritiva Steiner en la fenología del cáñamo medicinal, y determinar la dosis óptima de la solución nutritiva para el contenido de cannabinoides (cannabidiol [CBD] y tetrahidrocannabinol [THC]). La investigación fue realizada en el Instituto Nacional de Investigaciones Agropecuarias [INIAP], Estación Experimental Santa Catalina [EESC], en Ecuador, en condiciones de invernadero. Se emplearon cinco concentraciones de solución nutritiva de Steiner (50, 75, 100, 125 y 150%). Se evaluaron variables agronómicas como altura de planta, diámetro a la altura del cuello, rendimiento y contenido de cannabinoides en las flores. Se observó efecto significativo (p > 0,05) en altura de planta y diámetro del cuello. El THC se mantuvo < 1%. Concentraciones al 75% y 100% de la solución nutritiva mostraron niveles superiores de CBD con 15,3 y 15,15%, respectivamente. La solución nutritiva al 125 y 100% promovieron un mayor crecimiento en altura y diámetro a la altura del cuello. La concentración al 125% también produjo mayor rendimiento de biomasa seca con 810 g m-2 o 8,10 t ha-1, superando al resto de concentraciones. Se concluye que la concentración óptima de solución Steiner fue de 125% para acumulación de biomasa seca, y del 75 y 100% para la producción de cannabinoides en flores (CBD), cumpliendo con las regulaciones vigentes (< 1% de THC).

RESUMO A salinidade é um fator abiótico que prejudica o crescimento e os mecanismos fisiológicos, bioquímicos e moleculares das plantas. Entre as plantas, a soja é uma cultura importante mundialmente, portanto, o manejo de fatores abióticos é essencial para mitigar os danos às plantas. No entanto, bioestimulantes, como a melatonina, estão sendo usados para aliviar o estresse causado por esses fatores. Portanto, este estudo teve como objetivo avaliar o crescimento, os pigmentos fotossintéticos e as relações hídricas de plantas de soja aplicadas a níveis de salinidade e aplicação exógena de melatonina. A pesquisa foi realizada em área experimental pertencente à Universidade Federal Rural do SemiÁrido, Mossoró, RN, Brasil. O delineamento experimental foi em blocos casualizados, arranjados em esquema fatorial 3 x 3 (três níveis de salinidade na água de irrigação - 0.50, 3.00 e 5.00 dS m-1 e três concentrações de melatonina - 0, 0.5 e 1 mM), com três repetições. Aos 47 dias após o plantio, foram avaliados a altura da planta, diâmetro do caule, número de folhas, comprimento radicular, teor de clorofila (a, b e total), conteúdo relativo de água, umidade foliar e extravasamento de eletrólitos. As plantas de soja toleraram os efeitos da salinidade nos aspectos de crescimento, nos pigmentos fotossintéticos e nas relações hídricas até 3,00 dS m-1, independentemente da concentração de melatonina. A aplicação exógena de melatonina mitigou os efeitos do estresse salino na clorofila b e no conteúdo relativo de água, no nível de salinidade de 5.00 dS m-1 e concentração de 1 mM. fisiológicos mundialmente portanto entanto bioestimulantes Portanto SemiÁrido Mossoró RN Brasil casualizados 050 0 50 0.50 300 00 3.0 500 5 5.0 m1 m m- 05 0. mM, mM , mM) repetições 4 plantio planta caule folhas radicular a, (a total, total total) eletrólitos 3,0 m1, 1, 30 3. 5. 3,

ABSTRACT Salinity is an abiotic factor that impairs the growth and physiological, biochemical, and molecular mechanisms of plants. Among plants, soybeans are an important crop worldwide, so managing abiotic factors is essential to mitigate plant damage. However, biostimulants, such as melatonin, are being employed to alleviate the stress caused by these factors. Therefore, this study aimed to evaluate the growth, photosynthetic pigments, and water relations of soybean plants subjected to salinity levels and exogenous melatonin application. The research was conducted in experimental area belonging to the Federal Rural University of the Semi-Arid Region, Mossoró, RN, Brazil. The experimental design was randomized blocks, arranged in a 3 x 3 factorial scheme (three salinity levels in the irrigation water - 0.50, 3.00, and 5.00 dS m-1 and three melatonin concentrations - 0, 0.5, and 1 mM) with three replications. At 47 days after planting, plant height, stem diameter, number of leaves, root length, chlorophyll content (a, b, and total), relative water content, leaf moisture, and electrolyte leakage were evaluated. Soybean plants tolerated the effects of salinity on growth aspects, photosynthetic pigments, and water relations up to 3.00 dS m-1, regardless of melatonin concentration. Exogenous application of melatonin mitigated the effects of salt stress on chlorophyll b and relative water content at salinity level of 5.00 dS m-1 and concentration of 1 mM. physiological biochemical worldwide damage However biostimulants Therefore pigments SemiArid Semi Arid Region Mossoró RN Brazil blocks 050 0 50 0.50 300 00 500 5 5.0 m1 m m- 05 0.5 mM replications 4 planting height diameter leaves length a, (a total, total , total) moisture evaluated aspects 3.0 m1, 1, 30 5. 0. 3.

RESUMO: O estudo das relações genotípicas entre índices de tolerância à seca e caracteres agronômicos de interesse no melhoramento de trigo é útil para traçar estratégias de seleção. Objetivou-se com este trabalho investigar as relações de causa e efeito entre características agronômicas e índices de tolerância à seca via análise de correlações canônicas. Dois ensaios (controle e estresse) foram conduzidos no inverno de 2020 em Viçosa, MG, Brasil. Foram avaliados os caracteres (dias para o espigamento, altura da planta, massa e número de grãos por espiga, massa de cem grãos e rendimento de grãos). Os dados de produtividade dos ensaios de controle e estresse foram utilizados para construir cinco índices de tolerância à seca. Os dados foram submetidos à análise de modelos mistos para estimação dos parâmetros genéticos e predição dos valores genotípicos (REML/BLUP), em seguida, os valores genotípicos foram utilizados para calcular os coeficientes de correlação entre os caracteres. Dois grupos de caracteres foram estabelecidos para o estudo das correlações canônicas, sendo o primeiro grupo constituído pelas variáveis agronômicas e o segundo pelos índices de tolerância à seca. Houve efeito significativo de genótipo para todas as características avaliadas. Os pares canônicos foram significativos, o que indicou a existência de dependência entre os grupos. O caráter dias para o espigamento pode ser utilizado na seleção indireta de genótipos de trigo para tolerância à seca. RESUMO Objetivouse Objetivou se canônicas 202 Viçosa MG Brasil planta espiga grãos. . grãos) REML/BLUP, REMLBLUP REML/BLUP , REML BLUP (REML/BLUP) seguida avaliadas significativos 20 (REML/BLUP 2

ABSTRACT: The study of genotypic relationships between drought tolerance indices and agronomic traits of interest in wheat breeding is useful for designing selection strategies. The objective of this research was to investigate the cause-and-effect relationships between agronomic traits and drought tolerance indices through the analysis of canonical correlations. Two trials (control and stress) were conducted in winter 2020 in Viçosa, MG, Brazil. The traits evaluated were: (days for heading, plant height, mass and number of grains per spike, mass of one hundred grains, and grain yield). Grain yield data from the control and stress conditions were used to construct five drought tolerance indices. The data were subjected to mixed model analysis for estimation of genetic parameters and prediction of genotypic values (REML/BLUP), and then the genotypic values were used to calculate the correlation coefficients between the traits. Two groups of traits were established for the study of canonical correlations, the first group consisting of agronomic traits and the second by drought tolerance indices. There was a significant genotype effect for all evaluated traits. The canonical pairs were significant, which indicated the existence of dependence between the groups. Days to heading trait can be used in the indirect selection of wheat genotypes for drought tolerance. ABSTRACT strategies causeandeffect cause correlations 202 Viçosa MG Brazil days height spike yield. . yield) REML/BLUP, REMLBLUP REML/BLUP , REML BLUP (REML/BLUP) 20 (REML/BLUP 2

RESUMO A cultura do sorgo é considerada uma das mais importantes do mundo devido a sua versatilidade de utilização. No entanto, o estresse hídrico pode ser considerado uma ameaça significativa para sua produtividade. A busca por produtos mitigadores do estresse hídrico é uma área de pesquisa crucial na agricultura e na gestão de recursos hídricos. Assim, o objetivo deste trabalho foi avaliar a viabilidade do uso do ácido salicílico como atenuante de estresse hídrico na cultura do sorgo. O experimento foi conduzido em ambiente telado, em delineamento em blocos ao acaso com esquema fatorial 4 × 2, com quatro repetições. Foram avaliados quatro níveis hídricos (40, 60, 80 e 100% da evapotranspiração) e duas concentrações de ácido salicílico (0 e 2,76 g L-1). Foram analisados a altura das plantas, diâmetro do caule, número de folhas, trocas gasosas, pigmentos fotossintéticos e fluorescência da clorofila a. A aplicação de lâminas de irrigação deficitárias reduziu a altura da planta, diâmetro do colmo, número de folhas e clorofila total no sorgo. No entanto, quando essas lâminas foram associadas ao ácido salicílico, foi observado que houve atenuação dos danos, especialmente em relação a clorofila a e b. Além disso, o ácido salicílico quando aplicado isoladamente, contribuiu para redução da temperatura da folha e aumento da eficiência de uso da água. Assim, o ácido salicílico pode ser usado para mitigar os efeitos do estresse salino em plantas de sorgo. utilização entanto produtividade Assim telado 2 repetições 40, 40 (40 60 8 100 evapotranspiração 0 ( 276 76 2,7 L1. L1 L 1 . L-1) caule gasosas planta colmo danos b disso isoladamente água (4 6 10 27 7 L-1 L-

ABSTRACT The sorghum crop is considered one of the most important worldwide due to its versatility. However, water stress can be considered a significant threat to its yield. The search for products that mitigate water stress is a crucial area of research in agriculture and water resources management. Thus, the objective in this study was to evaluate the feasibility of using salicylic acid as a water stress attenuator in sorghum. The experiment was conducted in a screened environment in a randomized block design with a 4 × 2 factorial scheme, with four replicates. Four levels of water (40, 60, 80, and 100% of evapotranspiration) and two concentrations of salicylic acid (0 and 2.76 g L-1) were evaluated. Plant height, stem diameter, number of leaves, gas exchange, photosynthetic pigments, and chlorophyll a fluorescence were analyzed. Application of deficit irrigation depths reduced plant height, stem diameter, number of leaves, and total chlorophyll in sorghum. However, when these depths were associated with salicylic acid, it was observed that the damage was attenuated, especially in chlorophyll a and b. Furthermore, salicylic acid reduced leaf temperature and increased water use efficiency when applied alone. Thus, salicylic acid can be used to mitigate the effects of salt stress on sorghum plants. versatility However yield management Thus scheme replicates 40, 40 (40 60 80 100 evapotranspiration 0 ( 276 76 2.7 L1 L 1 L-1 evaluated height diameter leaves exchange pigments analyzed attenuated b Furthermore alone plants (4 6 8 10 27 7 2. L-

RESUMO Devido às importantes funções do cálcio na fisiologia vegetal, a suplementação deste nutriente pode ser uma estratégia viável para aumentar a tolerância das plantas à salinidade. Assim, o objetivo deste estudo foi avaliar as trocas gasosas e o crescimento de cultivares de rúcula de folhas largas cultivadas em fibra de coco submetidas ao estresse salino. Quatro soluções nutritivas [(S1-solução nutritiva padrão (condutividade elétrica da água - CEa de 0,5 dS m-1; S2- solução nutritiva utilizando água salina com NaCl a 3,5 dS m-1; S3-S2 enriquecida com Ca(NO3)2 a 50%; S4-S2 enriquecido com Ca(NO3)2 a 100%, obtendo valores de 2,3, 5,1, 5,5 e 5,9 dS m-1, para S1, S2, S3 e S4, respectivamente], e duas cultivares de rúcula. (Donatella e Gigante Folha Larga), dispostas em esquema fatorial 2 × 4, com três repetições, foram estudadas. As plantas foram colhidas 40 dias após a semeadura e avaliadas quanto às seguintes variáveis: altura de planta, número de folhas, área foliar, massa fresca total, massa seca total, área foliar específica, suculência foliar, índice relativo de clorofila, condutância estomática, taxa de assimilação de CO2, taxa de transpiração, concentração interna de CO2 e eficiência instantânea do uso da água e eficiência intrínseca de carboxilação. A cultivar Gigante Folha Larga foi mais tolerante à salinidade da solução nutritiva. O uso de solução nutritiva salinizada afetou negativamente o crescimento e a fisiologia da rúcula, mas a adição extra de Ca(NO3)2 reduziu os efeitos nocivos da salinidade. Recomenda-se adição extra de 50% de Ca(NO3)2 na solução nutritiva para reduzir o efeito do estresse salino. vegetal Assim salino S1solução Ssolução S1 S condutividade 05 0 5 0, m1 m 1 m-1 S2 35 3 3, S3S2 SS S3-S CaNO32 CaNO Ca NO3 NO Ca(NO3) 50 S4S2 S4 S4-S 100 100% 23 2,3 51 5,1 55 5, 59 9 m1, 1, respectivamente, respectivamente , respectivamente] Donatella Larga, Larga) 4 repetições estudadas variáveis planta total específica clorofila estomática CO transpiração carboxilação Recomendase Recomenda se m- S3S CaNO3 Ca(NO3 S4S 10 2, Ca(NO

ABSTRACT Due to the important functions of calcium in plant physiology, supplementation of this nutrient may be a viable strategy to increase the tolerance of plants to salinity. Thus, the objective in this study was to evaluate the gas exchange and growth of broad-leaf arugula cultivars cultivated in coconut fiber subjected to salt stress. Four nutrient solutions [(S1 - standard nutrient solution (electrical conductivity of water - ECw of 0.5 dS m-1; S2 - nutrient solution using saline water with NaCl at 3.5 dS m-1; S3 - S2 enriched with Ca(NO3)2 at 50%; S4 - S2 enriched with Ca(NO3)2 at 100%, obtaining values of 2.3, 5.1, 5.5, and 5.9 dS m-1, for S1, S2, S3, and S4, respectively], and two cultivars of arugula (Donatella and Gigante Folha Larga), arranged in a 2 × 4 factorial scheme, with three replicates, were studied. Plants were harvested 40 days after sowing and evaluated for the following variables: plant height, number of leaves, leaf area, total fresh mass, total dry mass, specific leaf area, leaf succulence, relative chlorophyll index, stomatal conductance, CO2 assimilation rate, transpiration rate, internal CO2 concentration, instantaneous water use efficiency, and intrinsic carboxylation efficiency. The cultivar Gigante Folha Larga was more tolerant to salinity of nutrient solution. The use of salinized nutrient solution negatively affected arugula growth and physiology, but the extra addition of Ca(NO3)2 reduced the harmful effects of salinity. Extra addition of 50% of Ca(NO3)2 in the nutrient solution is recommended to reduce the effect of salt stress. physiology Thus broadleaf broad stress S1 S [(S electrical 05 0 5 0. m1 m 1 m-1 35 3 3. CaNO32 CaNO Ca NO3 NO Ca(NO3) 50 100 100% 23 2.3 51 5.1 55 5.5 59 9 5. m1, 1, respectively, respectively , respectively] Donatella Larga, Larga) scheme replicates studied variables height leaves area mass succulence index conductance CO rate concentration efficiency m- CaNO3 Ca(NO3 10 2. Ca(NO

RESUMO: O lúpulo (Humulus lupulus L.) possui grande importância econômica no planalto serrano do estado de Santa Catarina, uma vez que existem inúmeras cervejarias nesta região do Brasil. Como as cultivares disponíveis no país carecem de bons atributos qualitativos e apresentam baixa produtividade de cones, existe grande demanda por genótipos melhorados. Os resultados de experimentos de cruzamento dialélico aumentam a compreensão dos processos de herança e dos mecanismos de controle associados à transferência de alelos com ação aditiva ou não aditiva, permitindo assim que os geneticistas explorem os benefícios da heterose. Os objetivos deste estudo foram avaliar as capacidades de combinação geral e específica (CGC e CEC, respectivamente) de quatro genótipos de lúpulo e obter híbridos F1 com características agronômicas superiores às dos genitores e habilidade para se adaptar às condições ambientais do planalto catarinense. Os cruzamentos dialélicos parciais foram realizados em delineamento de blocos casualizados envolvendo 14 tratamentos, i.e. dois genitores masculinos (Cascade e Hallertauer), quatro genitores femininos (Columbus, Chinook, Cascade e Hallertauer) e oito combinações híbridas, com três repetições cada. Os resultados mostraram que a CEC dos genitores foi o mecanismo de controle predominante para a manifestação nos híbridos das características comprimento do ramo lateral, altura de inserção do primeiro cone, massa verde da planta e produtividade de cones. Algumas combinações entre genitores também manifestaram CGC elevada, indicando a presença de alelos favoráveis com ação aditiva. A melhor combinação foi Hallertauer × Cascade e essa descoberta demonstra a importância da escolha de genitores originários de diferentes grupos genéticos (Americano × Europeu) para obter híbridos geneticamente melhorados. RESUMO Humulus L. L Catarina Brasil cones melhorados heterose respectivamente F catarinense 1 tratamentos ie i i.e Hallertauer, , Columbus, Columbus (Columbus Chinook híbridas cada lateral cone elevada Americano Europeu

ABSTRACT: Hops (Humulus lupulus L.) are of particular economic importance in the highlands of the state of Santa Catarina, Brazil, by virtue of the number of breweries in the region. However, since the cultivars currently available in the country present poor qualitative attributes and low cone productivity, there is considerable demand for improved genotypes. The results of diallel crossing experiments help to increase our understanding of inheritance processes and the mechanisms controlling the transfer of alleles with additive or non-additive action, thereby allowing breeders to explore the benefits of heterosis. The present study evaluated the general and specific combining abilities (GCA and SCA, respectively) of four hop genotypes and to obtain F1 hybrids with agronomic traits superior to those of the parents and the ability to adapt to the environmental conditions in the Santa Catarina highlands. Partial diallel crosses were performed using a randomized complete block design involving 14 treatments, namely two male parents (Cascade and Hallertauer), four female parents (Columbus, Chinook, Cascade and Hallertauer) and eight hybrid combinations, with three repetitions each. The results showed that SCA was the predominant controlling mechanism for the manifestation in hybrids of the traits length of the lateral branch, height of insertion of the first cone, plant green mass and cone productivity. Some parental combinations also exhibited high GCA, indicating the presence of favorable alleles with additive action. The best combination was Hallertauer × Cascade, a finding that highlights the importance of choosing parents from different gene pools (American × European) to obtain genetically enhanced hybrids. ABSTRACT Humulus L. L Brazil region However productivity nonadditive non action heterosis GCA respectively F 1 treatments Hallertauer, , Columbus, Columbus (Columbus Chinook each branch American European

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. Estudios de defoliación en caña de azúcar en México son escasos, se desconoce a qué edad de la planta y en qué época del año se deben realizar. Objetivo. Evaluar el efecto de la defoliación artificial en caña de azúcar en diferentes etapas de cultivo y su respuesta sobre parámetros de calidad y rendimiento. Materiales y métodos. El experimento se llevó a cabo en la zafra 2020-2021 entre los meses de abril y mayo, en una parcela ubicada en una soca del cultivar COLPOSCTMEX 06-039, dentro de la zona de abastecimiento del Ingenio Presidente Benito Juárez de la Chontalpa, Tabasco. Se utilizó un diseño experimental de bloques completamente al azar, donde los tratamientos de defoliación consistieron en eliminar las hojas completas del tallo hasta dejar la hoja +5 (H5). Los tratamientos de defoliación se aplicaron a los 8, 9 y 10 meses de edad del cultivo, más un testigo sin defoliación, con cinco repeticiones por tratamiento. Los parámetros de crecimiento evaluados fueron altura y diámetro de planta, número de tallos e índices de área foliar (IAF) y de vegetación de las diferencias normalizada (NDVI). Al momento de la cosecha se midieron los °Brix y los rendimientos agrícolas de la caña de azúcar. Resultados. Se encontró que los parámetros de crecimiento y calidad fueron disminuidos por los tratamientos de defoliación total. El tratamiento 2 mostró los mayores valores de altura y diámetro de planta, menor NDVI y rendimiento de tallos al momento de la cosecha y la defoliación afectó el IAF. Los °Brix no se vieron afectados por los diferentes tratamientos de defoliación. Conclusión. La defoliación a los nueve meses de edad aumentó el rendimiento agrícola y no afectó la calidad de los jugos.

Abstract Introduction. Defoliation studies on sugarcane in Mexico are scarce, and it is unknown at what age of the plant and in which season of the year it should be carried out. Objective. To evaluate the effect of artificial defoliation in sugarcane at different stages of growth and its response on quality and yield parameters. Materials and methods. The experiment was conducted during the 2020-2021 harvest between the months of April and May, in a plot located in a ratoon of the cultivar COLPOSCTMEX 06-039, within the supply area of the Ingenio Presidente Benito Juárez in the Chontalpa region, Tabasco. A completely randomized block design was used, where the defoliation treatments consisted of removing the entire leaves of the stem until leaving the +5 leaf (H5). Defoliation treatments were applied at 8, 9, and 10 months of crop age, plus a control without defoliation, with five replicates per treatment. Growth parameters evaluated were plant height and diameter, number of stalks, and leaf area index (IAF) and normalized difference vegetation index (NDVI). At harvest, °Brix and sugarcane yields of sugarcane were measured. Results. It was found that growth and quality parameters were reduced by total defoliation treatments. Treatment 2 showed the highest values of plant height and diameter, lower NDVI, and stalk yield at harvest, and defoliation affected the IAF. °Brix were not affected by different defoliation treatments. Conclusion. Defoliation at nine months of age increased agricultural yield and did not affect juice quality.

Resumen Introducción. Las especies silvestres son importantes en el ecosistema, estas requieren el desarrollo de técnicas que permitan su preservación. Objetivo. Determinar las características de germinación in situ y ex situ y el crecimiento en campo de las especies Porcelia mediocris N.A. Murray y Compsoneura trianae Warb. en Arosemena Tola, Napo, Ecuador. Materiales y métodos. El estudio se realizó entre 2019 y 2020, se colectaron semillas en el bosque primario de P. mediocris y C. trianae. Se desarrollaron pruebas de germinación en invernadero y en bosque primario, se midió la emergencia de las semillas, crecimiento en bandeja y se aplicó un análisis de varianza entre los sitios de ensayo. Las plántulas fueron trasplantadas en tres diferentes coberturas de suelo en el Centro de Enseñanza, Investigación y Productividad de la Amazonía, se tomaron medidas de crecimiento en altura, diámetro del tallo, número de hojas y supervivencia, se elaboraron las curvas de crecimiento y se realizó un análisis de varianza en las medidas finales de crecimiento entre las diferentes coberturas. Resultados. En P. mediocris, las plantas desarrolladas en invernadero reportaron menos días a la emergencia (67,6), pero las desarrolladas en la cobertura guabas tuvieron mayor altura (19,45 cm) y porcentaje de germinación (70 %) al final de la prueba. En C. trianae las plantas desarrolladas en el sitio de colecta tuvieron mayor altura (13,38 cm) y número de hojas al final de la evaluación. El crecimiento en campo no mostró diferencias entre coberturas y tuvo una supervivencia del 47 % en P. mediocris y 75 % en C. trianae. Conclusiones. P. mediocris reportó mejores porcentajes de germinación en la cobertura guabas y C. trianae tuvo mayor crecimiento en el bosque primario, sin que el sitio de germinación influyera en el crecimiento posterior al trasplante en ambas especies.

Abstract Introduction. Wild species are important in the ecosystem, and their preservation requires the development of effective techniques. Objective. To determine the in situ and ex situ germination characteristics and field growth of Porcelia mediocris N.A. Murray and Compsoneura trianae Warb. in Arosemena Tola, Napo, Ecuador. Materials and methods. The study was carried out between 2019 and 2020, with seeds collected from the primary forest of P. mediocris and C. trianae. Germination tests were conducted in a greenhouse and in the primary forest, measuring seed emergence, tray growth, and performing an analysis of variance between the testing sites. Seedlings were transplanted into three different soil covers at the Amazon Center for Teaching, Research, and Productivity, with measurements taken for height, stem diameter, number of leaves, and survival. Growth curves were created, and an analysis of variance was performed on the final growth measurements among the different soil covers. Results. For P. mediocris, greenhouse-grown plants showed fewer days to the emergence (67.6), but those grown under guaba cover had a greater height (19.45 cm) and germination percentage (70 %) at end of the trial. For C. trianae, plants grown at the collection site had greater height (13.38 cm) and number of leaves at the end of the evaluation. Field growth did not show differences between soil covers, with survival rate of 47 % for P. mediocris and 75 % for C. trianae. Conclusions. P. mediocris showed better germination percentages under guaba cover, while C. trianae exhibited greater growth in the primary forest, with the germination site not affecting post-transplant growth for either species.

Resumen Introducción. El mildiu de la quinua es una enfermedad que ocasiona pérdidas económicas y que ha sido poco estudiada, por lo que la investigación de la respuesta de la quinua a la enfermedad y las formas de tratamiento es un tema que debe investigarse con mayor profundidad. Objetivo. Describir cómo afecta la infección del mildiu velloso en la planta de la quinua y los métodos no tradicionales empleados en el control de esta enfermedad. Desarrollo. Se realizó una búsqueda sistemática a fin de realizar una recopilación de los resultados asociados al P. variabilis en la quinua (Chenopodium quinoa Wild.) en diversas condiciones. El análisis determinó que factores como la incidencia, la severidad y la tolerancia a la enfermedad del mildiu, dependieron en gran medida de la variedad de grano de quinua y la altitud (con sus condiciones climáticas). La altura de la planta y el rendimiento por hectárea estuvieron influenciados por las condiciones del suelo, el tratamiento empleado contra plagas y patógenos, y el día de siembra. Conclusiones. La incidencia y la severidad del mildiu velloso dependió de la variedad de la quinua con la que se trabajó. Otros factores como la altitud o la humedad también influyeron en el progreso de la enfermedad, con una infección cercana al 90 % en ambientes con alta humedad. Los métodos no convencionales para tratar el mildiu fueron infusiones de plantas como la manzanilla y el ajo, con resultados positivos a corto plazo; no obstante, no superaron a los tratamientos convencionales con fungicidas químicos.

Abstract Introduction. Quinoa downy mildew is a disease that causes economic losses and has been poorly studied.Therefore, researching quinoa’s response to the disease and treatment methods is a topic that requires further investigation. Objective. To describe how downy mildew infection affects quinoa plants and the non-traditional methods used to control this disease. Development. A systematic search was conducted to compile the results associated with P. variabilis in quinoa (Chenopodium quinoa Wild.) under various conditions. The analysis determined that factors such as incidence, severity, and disease tolerance depended largely on the quinoa grain variety and altitude (along with its climatic conditions). Plant height and yield per hectare were influenced by soil conditions, pest and disease treatment, and the planting day. Conclusions. The incidence and severity of downy mildew depended on the quinoa variety used. Other factors such as altitude or humidity also influenced disease progression, with infection rates close to 90 % in high humidity environments. Non-conventional methods for treating downy mildew included plant infusions such as chamomile and garlic, showing positive short-term results; however, they did not surpass conventional treatments with chemical fungicides.

RESUMEN El objetivo de este estudio fue evaluar el efecto de dos sistemas de sucesión de cultivos bajo siembra directa (SD) sobre las propiedades físicas y químicas del suelo, así como en el rendimiento de la soja en un Cambisol. El experimento se llevó a cabo en una finca ubicada en la aldea Paratodo, Pdte. Hayes, Paraguay, utilizando un diseño experimental en franjas con dos Cultivos de Cobertura (CC) como tratamientos: Megathyrsus maximus cv. Gatton Panic (Gatton) y una sucesión soja/trigo/soja (Trigo). Las variables evaluadas fueron biomasa aérea (BIOM), humedad gravimétrica (HG), concentración de nitrógeno (NO3-N y NH4-N), densidad aparente (DAP), resistencia a la penetración (RP), tasa de infiltración (TI), altura de la planta de soja y rendimiento del cultivo de soja. Los datos se analizaron mediante análisis de varianza con la prueba de Scott y Knott al 5% de significancia, prueba t para dos muestras con varianzas iguales, y se describieron tendencias mediante regresiones lineales y polinómicas. El tratamiento Gatton mostró una mayor capacidad de retención de HG durante el barbecho y desarrollo del cultivo, con valores medios durante todo el ensayo de 19,2% y 15,4% para Gatton y Trigo respectivamente. Además, Gatton presentó 2,09 veces más BIOM al inicio (11.311 versus 5.390 kg ha⁻¹) y descompuso 1,88 veces más residuo vegetal, registrando una mayor tasa de descomposición diaria en comparación con Trigo, con valores de 12,7 kg ha⁻¹ día⁻¹ y 9,5 kg ha⁻¹ día⁻¹, respectivamente. La DAP fue un 3% menor en Gatton (1,32 g cm-3) en comparación con Trigo (1,36 g cm-3), que aumentó con la profundidad (25-50 cm). El Trigo registró valores críticos de RP superiores a 3 MPa al momento de la siembra en la profundidad de 5-15 cm y al fin del ensayo en la profundidad de 5-20 cm. La altura de plantas de soja fue un 11,2% mayor con Gatton (99,6 cm versus 89,6 cm), donde también se obtuvo mayor rendimiento de granos (3.336 kg ha⁻¹) comparado con el Trigo (2.929 kg ha⁻¹), con una diferencia de 13,9%. El sistema de producción basado en un CC con Megathyrsus maximus cv. Gatton Panic mejora las propiedades físicoquímicas del suelo y aumenta el rendimiento de la soja.

ABSTRACT The objective of this study was to evaluate the effect of two crop succession systems under no-till (NT) on the physical and chemical properties of the soil, as well as soybean yield, in a Cambisol. The experiment was conducted on a farm located in the Paratodo village, Pdte. Hayes, Paraguay, using a strip plot design with two Cover Crops (CC) as treatments: Megathyrsus maximus cv. Gatton Panic (Gatton) and a soybean/wheat/soybean succession (Wheat). The variables evaluated were aboveground biomass (BIOM), gravimetric moisture (GM), nitrogen concentration (NO3-N and NH4-N), bulk density (BD), penetration resistance (PR), infiltration rate (IR), soybean plant height, and soybean yield (Glycine max L.). Data were analyzed using analysis of variance with the Scott y Knott test at 5% significance, a t-test for two samples with equal variances, and trends were described through linear and polynomial regressions. The Gatton treatment demonstrated a greater capacity for retaining GM during the fallow and crop development stages, with average values throughout the trial of 19,2% for Gatton and 15,4% for Wheat. Additionally, Gatton recorded 2,09 times more BIOM at the start (11.311 vs. 5.390 kg ha⁻¹) and decomposed 1,88 times more crop residue, showing a higher daily decomposition rate compared to Wheat, with values of 12,7 kg ha⁻¹ day⁻¹ and 9,5 kg ha⁻¹ day⁻¹, respectively. BD was 3% lower in Gatton (1,32 g cm⁻³) compared to Wheat (1,36 g cm⁻³), and it increased with soil depth (25-50 cm). Wheat recorded critical PR values exceeding 3 MPa at sowing at depths of 5-15 cm and at the end of the trial at depths of 5-20 cm. Soybean plant height was 11.2% higher with Gatton (99,6 cm vs. 89,6 cm), which also achieved greater grain yield (3.336 kg ha⁻¹) compared to Wheat (2.929 kg ha⁻¹), with a difference of 13,9%. The production system based on a CC with Megathyrsus maximus cv. Gatton Panic improves the soil’s physicochemical properties and increases soybean yield.

RESUMEN En Paraguay, el sésamo cumple una función social en el medio rural, debido a que es producido principalmente por pequeños agricultores. Sin embargo, aún son escasas las informaciones que identifiquen variedades con altos rendimientos. Este estudio tuvo como objetivo evaluar las características agronómicas y el contenido de aceite de cinco variedades de Sesamum indicum L. Los experimentos se realizaron en Saltos del Guairá e Ybyrarobana en la campaña agrícola 2022/23. El diseño experimental fue de bloques al azar con cinco repeticiones y cinco tratamientos correspondientes a cinco variedades de sésamo (Inia, Negro, KO7, SH1 y Escoba) en cada experimento. Las características evaluadas fueron altura de planta, número de cápsulas, peso de mil granos, rendimiento de grano y porcentaje de aceite en los granos. Se observó, en la variedad Escoba, la mayor altura de planta (174,50 cm), y las variedades Inia y Negro presentaron el mayor valor en peso de mil granos: 3,20 y 3,02 g, respectivamente. Para las variables número de cápsulas, productividad y contenido de aceite no se observaron diferencias.

ABSTRACT In Paraguay, sesame holds an important social role in rural areas, as it is primarily cultivated by small-scale farmers. However, limited information is available on varieties with high yield potential. This study aimed to evaluate the agronomic traits and oil content of five varieties of Sesamum indicum L. Field trials were conducted in Saltos del Guairá and Ybyrarobana during the 2022/23 growing season. The experimental design was a randomized block design with five replications and five treatments corresponding to five sesame varieties (Inia, Negro, KO7, SH1, and Escoba) in each experiment. The evaluated characteristics were plant height, number of capsules, thousand-grain weight, grain yield, and oil percentage in grains. The Escoba variety had the highest plant height (174.50 cm), and the Inia and Negro varieties had the highest thousand-kernel weight values of 3.20 and 3.02 g, respectively. No significant differences were observed in the number of capsules, productivity, or oil content among the varieties.

Abstract Broccoli is a non-traditional export crop for Ecuador. This study used the response surface methodology to optimize the fertilization of hybrid broccoli, Avenger. The research was conducted at Hacienda Las Mercedes, Cotopaxi province, Ecuador, at 2,913 meters above sea level. We evaluated the response of broccoli to different doses of N-P-K (Nitrogen, Phosphorus, and Potassium), with five levels ranging from 0 to 300 kg ha-1 of N, 0 to 70 kg ha-1 of P, and 0 to 180 kg ha-1 of K, along with one treatment without fertilization. The experimental design was a Central Composite Rotable Design (CCRD) 3K+1 with four replicates. The variables evaluated included plant height, compactness, equatorial diameter, and head yield. The results showed that: i) the greatest plant height (59.90 cm) was obtained with T13 (150 kg ha-1 N, 70 kg ha-1 P, 90 kg ha-. K); ii) the highest head compactness (1.12 kg cm-2) was found with T11 (300 kg ha-1 N, 35 kg ha-1 P, 90 kg ha-1 K); iii) the best equatorial diameter (197.80 mm) and yield (25.25 t ha-1) were achieved with T8 (239 kg ha-1 N, 56 kg ha-1 P, 144 kg ha-1 K); and iv) the response surface model suggested an optimal dose of 178 kg ha-1 N, 70 kg ha-1 P, and 25 kg ha-1 K for a yield of 26.5 t ha-1. We can conclude that the model adequately fits the crop yield.

Resumen El brócoli es un cultivo no tradicional de exportación para Ecuador. Este estudio utilizó la metodología de superficie de respuesta para optimizar la fertilización de brócoli híbrido Avenger. La investigación se llevó a cabo en la hacienda Las Mercedes, provincia de Cotopaxi, Ecuador, a una altitud de 2.913 m s. n. m. Se evaluó la respuesta del brócoli a diferentes dosis de N-P-K (nitrógeno, fósforo y potasio) con cinco niveles de dosis crecientes desde 0 a 300 kg ha-1 de N, 0 a 70 kg ha-1 de P y 0 a 180 kg ha-1 de K, y un tratamiento sin fertilización. El diseño experimental fue un compuesto central rotable (DCCR) 3K+1 con cuatro repeticiones. Las variables evaluadas incluyeron la altura de la planta, compactación, diámetro ecuatorial y rendimiento de la pella. Los resultados mostraron que: i) la más grande altura de la planta (59,90 cm) se obtuvo con T13 (150 kg ha-1 N, 70 kg ha-1 P, 90 kg ha-1 K); ii) la mayor compactación de la pella (1,12 kg cm-2) se encontró con T11 (300 kg ha-1 N, 35 kg ha-1 P, 90 kg ha-1 K); iii) el mejor diámetro ecuatorial (197,80 mm) y rendimiento (25,25 t ha-1) se lograron con T8 (239 kg ha-1 N, 56 kg ha-1 P, 144 kg ha-1 K); y iv) el modelo de superficie de respuesta sugirió una dosis óptima de 178 kg ha-1 N, 70 kg ha-1 P y 25 kg ha-1 K para un rendimiento de 26,5 t ha-1. En conclusión, el modelo ajusta de manera aceptable el rendimiento del cultivo.

Abstract Okra (Hibiscus esculentus) is an annual herbaceous and non-traditional vegetable with high nutritional value and health benefits. Despite its importance, the lack of information on its cultivation in this region has led many Amazonian farmers to manage it empirically, combining foliar chemical fertilizers with organic fertilizers without a scientific basis for determining the most suitable combination. In this context, the objective of this research was to evaluate the impact of applying compost and chicken manure combined with foliar chemical fertilizers (Stimufol and Kristalon) on the development of aerial morphological traits of Hibiscus esculentus crops under field conditions in the Amazonian region of Ecuador. The experiment was conducted at the Experimental Center for Amazonian Research and Production of the Universidad Estatal Amazónica, using a completely randomized block design with two factors: organic fertilization and chemical foliar fertilization. Key morphological variables of the crop were evaluated, such as plant height, stem base diameter, number of leaves, petiole length, and leaf length and width. The results showed that plants treated with organic compost and chemical fertilizer Stimufol showed a significant increase in all morphological measurements compared to the other treatments. Finally, the combination of Stimufol and compost plays a crucial role in the development of okra's morphological attributes, while the absence of this treatment did not affect said attributes.

Resumen La okra (Hibiscus esculentus) es una planta herbácea anual y hortaliza "no tradicional" de gran valor nutricional y beneficios para la salud. A pesar de su importancia, la falta de información sobre su cultivo en esta región ha llevado a muchos agricultores amazónicos a gestionarla de forma empírica, combinando fertilizantes químicos foliares con abonos orgánicos sin una base científica para determinar la combinación más adecuada. En este contexto, el objetivo de esta investigación fue evaluar el impacto de la aplicación de compost y gallinaza combinado con fertilizantes químicos foliares Stimufol y Kristalon en el desarrollo de los rasgos morfológicos aéreos del cultivo Hibiscus esculentus, en condiciones de campo, en la región amazónica de Ecuador. El experimento se llevó a cabo en el Centro Experimental de Investigación y Producción Amazónica de la Universidad Estatal Amazónica, utilizando un diseño de bloque completamente al azar con dos factores: fertilización orgánica y fertilización foliar química. Se evaluaron variables morfológicas clave del cultivo, como altura de la planta, diámetro en la base del tallo, número de hojas, longitud del peciolo, longitud y ancho de la hoja. Los resultados demostraron que las plantas tratadas con abono orgánico compost y fertilizante químico Stimufol mostraron un notable incremento en todas las mediciones morfológicas en comparación con los otros tratamientos. Finalmente, la combinación de Stimufol y compost juega un papel esencial en el desarrollo de los atributos morfológicos de la okra, mientras que la falta de este tratamiento no tuvo efecto en dichos atributos.

Abstract: The use of seaweed or Sargassum as a biostimulant is an alternative to chemical fertilizers in agricultural systems. The objective of this study was to evaluate the yield of perennial ryegrass (Lolium perenne L.) subjected to different harvest frequencies and fertilized at different biofertilizer concentrations based on brown seaweed or Sargassum (Sargassum spp.) over a one-year period. For this, concentrations of 0, 2, 5 and 8% of the biostimulant and defoliation intervals of 28, 35 and 42 days were considered as factors, evaluating the four seasons of the year. The variables evaluated were dry matter yield, Soil Plant Analysis Development in Soil (SPAD) units, plant height, and leaf tissue production. A completely randomized design was used, with a 4x3 factorial arrangement with 4 replications per treatment. Mean comparisons were performed by Tukey test (P<0,05), using a factorial ANOVA in SAS software (2002). The results showed that, except for SPAD units, the Sargassum extract had no effect (P<0,05) on any of the variables evaluated. Regarding harvest frequency, the 42-day interval showed the highest forage yields, plant height, and leaf production over the seasons evaluated, but there was no effect on the accumulated dry matter yield. It is concluded that the highest level of Sargassum extract (8%) influences chlorophyll concentration, while harvest frequency and season of the year have effects (P<0,01) on yield variables.

Resumen: El uso del Sargazo como bioestimulante es una alternativa a la aplicación de fertilizantes químicos en sistemas de producción agrícola. El objetivo de este estudio fue evaluar el rendimiento de ballico perenne (Lolium perenne L.) sometido a diferentes estrategias de defoliación y fertilizado a diferentes concentraciones de un biofertilizante a base de algas pardas o Sargazo (Sargassum spp.) durante un año de evaluación. Para ello, se consideraron como factores las concentraciones de 0, 2, 5 y 8% del bioestimulante y frecuencias de cosecha cada 28, 35 y 42 días, evaluando las cuatro estaciones del año. Las variables evaluadas fueron: rendimiento de materia seca, unidades SPAD (Análisis del Desarrollo de la Planta en el Suelo), altura de forraje y producción de tejido foliar. Se utilizó un diseño completamente al azar, con arreglo factorial 4 x 3, con 4 repeticiones por tratamiento. Las medias de tratamientos fueron comparadas por Tukey (P<0,05), utilizando el procedimiento Factorial ANOVA del software SAS (2002). Los resultados indican que, a excepción de las unidades SPAD, el extracto de Sargazo no registró efecto (P>0,05) en ninguna de las variables evaluadas. Con respecto a frecuencia de cosecha, el intervalo de 42 días evidenció los mayores rendimientos de forraje, altura de la planta y producción de hoja en las épocas evaluadas, pero sin efecto en el rendimiento acumulado de materia seca. Se concluye que el nivel alto del extracto de Sargazo (8%) tienen efecto en la concentración de clorofila, mientras que la frecuencia de defoliación y la época del año tienen efecto (P<0,01) sobre las variables del rendimiento.