Enhancing garlic propagation through functional biopolymer-based propagules coatings: A bio-nanotechnological strategy.

Integrating agricultural, chemical, and technological knowledge is crucial for developing bio-nanotechnologies to improve agricultural production. This study explores the innovative use of biopolymeric coatings, based on sodium alginate and sodium alginate + Laponite® (nanoclay), containing biostimulants (tryptophol and thymol) or not, on garlic cloves. These coatings were analyzed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR-ATR), and scanning electron microscopy (SEM). Greenhouse bioassays showed improvements in garlic shoot plant biomass with both treatments: sodium alginate biopolymer and sodium alginate biopolymer plus Laponite®. In the field experiment, garlic plants treated with sodium alginate, in combination with conventional pesticide treatments, resulted in better quality garlic bulbs, where larger garlics were harvested in this treatment, reducing commercial losses. In tropical garlic crops, obtaining plants with greater initial vigor is essential. Our results highlight the potential of these bio-nanotechnological strategies to enhance garlic propagation, ensuring environmental protection and food security.

A cascade approach to sustainable agriculture: From mushroom mycelium to lettuce harvest.

Sustainable agriculture involves adopting best practices in food production to promote environmental and economic sustainability. Its implementation primarily aims to utilise organic residues to increase yield, diversify production, and reduce costs. In this context, the objective of this study was to investigate different substrates for Hypsizygus ulmarius production and, from its residual substrate, to develop formulations for lettuce seedling growth and subsequent greenhouse cultivation. For mushroom production, substrates were prepared from sawdust with the addition of wheat bran, rice bran, soybean meal, and calcite, resulting in four distinct substrate formulations. The spent mushroom substrate (SMS), obtained at the end of cultivation, was used for lettuce seedling production along with the commercial substrate Carolina Soil® and the soil conditioner BacSol®. The top five formulations were selected for transplanting in the greenhouse. Regarding mushroom production, substrates with higher carbon/nitrogen ratios, around 66: 1, resulted in higher yields. For seedling production, SMS showed lower efficiency compared to the commercial substrate Carolina Soil®, which also benefited from the addition of the soil conditioner BacSol®. However, after transplanting lettuce seedlings, the formulation containing SMS showed superior results in almost all evaluated parameters. Therefore, we concluded that despite the inefficiency of using H.ulmarius SMS for lettuce seedling production, it favours the establishment of seedlings in greenhouse cultivation environments.

Tolerance Evaluation of Celery Commercial Cultivars and Genetic Variability of Fusarium oxysporum f. sp. apii.

Celery (Apium graveolens var. dulce) is affected by several plant diseases, such as Fusarium oxysporum f. sp. apii (Foa). Four Foa races have been found in the US. The goals of this study were to determine which races are present in Costa Rica and to quantify the tolerance of the imported commercial cultivars of celery produced in the country. Isolates from 125 symptomatic celery plants from three different geographical locations were analyzed, 65 of which were selected for phylogenetic analysis. All isolates presented a short sequence of five nucleotides that differentiates Foa race 3 in the IGS rDNA region. Three different haplotypes closely related to race 3 were found, which were highly virulent, produced great losses, and affected all cultivars (resistant to races 2 and 4) of imported commercial celery. Additionally, five different cultivars of celery were evaluated against seven pathogen isolates identified as race 3 in greenhouse conditions. Two of the cultivars showed significantly less chlorosis, wilting, mortality, and higher fresh weight. Most of the Foa isolates significantly increased chlorosis, wilting, and mortality compared to non-inoculated control. Celery producers in Costa Rica lack access to seeds resistant to the Foa race 3 present in the country.

Evaluation of the Effect of the ENSO Cycle on the Distribution Potential of the Genus Anastrepha of Horticultural Importance in the Neotropics and Panama.

Climate variability has made us change our perspective on the study of insect pests and pest insects, focusing on preserving or maintaining efficient production systems in the world economy. The four species of the genus Anastrepha were selected for this study due to their colonization and expansion characteristics. Models of the potential distribution of these species are scarce in most neotropical countries, and there is a current and pressing demand to carry out this type of analysis in the face of the common scenarios of climate variability. We analyzed 370 presence records with statistical metrics and 16 bioclimatic variables. The MaxEnt method was used to evaluate the effect of the ENSO cycle on the potential distribution of the species Anastrepha grandis (Macquart), Anastrepha serpetina (Wiedemann), Anastrepha obliqua (Macquart), and Anastrepha striata (Schiner) as imported horticultural pests in the neotropics and Panama. A total of 3472 candidate models were obtained for each species, and the environmental variables with the greatest contribution to the final models were LST range and LST min for A. grandis, PRECIP range and PRECIP min for A. serpentina, LST range and LST min for A. obliqua, and LST min and LST max for A. striata. The percentage expansion of the range of A. grandis in all environmental scenarios was 26.46 and the contraction of the range was 30.80; the percentage expansion of the range of A. serpentina in all environmental scenarios was 3.15 and the contraction of the range was 28.49; the percentage expansion of the range of A. obliqua in all environmental scenarios was 5.71 and the contraction of the range was 3.40; and the percentage expansion of the range of A. striata in all environmental scenarios was 41.08 and the contraction of the range was 7.30, and we selected the best model, resulting in a wide distribution (suitable areas) of these species in the neotropics that was influenced by the variability of climatic events (El Niño, Neutral, and La Niña). Information is provided on the phytosanitary surveillance systems of the countries in areas where these species could be established, which is useful for defining policies and making decisions on integrated management plans according to sustainable agriculture.

Comparative analyses of Theobroma cacao and T. grandiflorum mitogenomes reveal conserved gene content embedded within complex and plastic structures.

Unlike the chloroplast genomes (ptDNA), the plant mitochondrial genomes (mtDNA) are much more plastic in structure and size but maintain a conserved and essential gene set related to oxidative phosphorylation. Moreover, the plant mitochondrial genes and mtDNA are good markers for phylogenetic, evolutive, and comparative analyses. The two most known species in Theobroma L. (Malvaceae s.l.) genus are T. cacao, and T. grandiflorum. Besides the economic value, both species also show considerable biotechnology potential due to their other derived products, thus, aggregating additional economic value for the agroindustry. Here, we assembled and compared the mtDNA of Theobroma cacao and T. grandiflorum to generate a new genomics resource and unravel evolutionary trends. Graph-based analyses revealed that both mtDNA exhibit multiple alternative arrangements, confirming the dynamism commonly observed in plant mtDNA. The disentangled assembly graph revealed potential predominant circular molecules. The master circle molecules span 543,794 bp for T. cacao and 501,598 bp for T. grandiflorum, showing 98.9% of average sequence identity. Both mtDNA contains the same set of 39 plant mitochondrial genes, commonly found in other rosid mitogenomes. The main features are a duplicated copy of atp4, the absence of rpl6, rps2, rps8, and rps11, and the presence of two chimeric open-reading frames. Moreover, we detected few ptDNA integrations mainly represented by tRNAs, and no viral sequences were detected. Phylogenomics analyses indicate Theobroma spp. are nested in Malvaceae family. The main mtDNA differences are related to distinct structural rearrangements and exclusive regions associated with relics of Transposable Elements, supporting the hypothesis of dynamic mitochondrial genome maintenance and divergent evolutionary paths and pressures after species differentiation.

Sample size affects the precision of the analysis of variance in experiments with cauliflower seedlings / O tamanho de amostra afeta a precisão da análise de variância em experimentos com mudas de couve-flor

ABSTRACT: This study verified whether sample size would affect the precision of the analysis of variance in experiments with cauliflower seedlings. An experiment was carried out where the number of leaves and shoot, root and total length were measured. For each variable, resamplings with repositions were performed in sample scenarios of 1, 2, …, 100 seedlings per experimental unit, and the sample size was defined for the variance components through Schumacher models and maximum curvature points. The mean squares of the analysis of variance suffer direct interference from the number of sampled seedlings. The sampling of 16 seedlings per experimental unit is enough to estimate the analysis of variance reliably, promoting satisfactory precision gains compared to the sampling of only one seedling per experimental unit.

RESUMO: Este estudo verificou se o tamanho de amostra afetaria a precisão da análise de variância em experimentos com mudas de couve-flor. Um experimento foi conduzido onde o número de folhas, comprimento de parte aérea, raiz e total foram mensurados. Para cada variável, reamostragens com reposição foram realizadas em cenários amostrais de 1, 2, ..., 100 mudas por unidade experimental e o tamanho de amostra foi definido para os componentes de variância por meio de modelos de Schumacher e pontos de máxima curvatura. Os quadrados médios da análise de variância sofrem interferência direta do número de mudas amostradas. A amostragem de 16 mudas por unidade experimental é suficiente para estimar a análise de variância de forma confiável, promovendo satisfatórios ganhos de precisão ao comparar-se com a amostragem de apenas uma muda por unidade experimental.

Sample size affects the precision of the analysis of variance in experiments with cauliflower seedlings / O tamanho de amostra afeta a precisão da análise de variância em experimentos com mudas de couve-flor

This study verified whether sample size would affect the precision of the analysis of variance in experiments with cauliflower seedlings. An experiment was carried out where the number of leaves and shoot, root and total length were measured. For each variable, resamplings with repositions were performed in sample scenarios of 1, 2, …, 100 seedlings per experimental unit, and the sample size was defined for the variance components through Schumacher models and maximum curvature points. The mean squares of the analysis of variance suffer direct interference from the number of sampled seedlings. The sampling of 16 seedlings per experimental unit is enough to estimate the analysis of variance reliably, promoting satisfactory precision gains compared to the sampling of only one seedling per experimental unit.

Este estudo verificou se o tamanho de amostra afetaria a precisão da análise de variância em experimentos com mudas de couve-flor. Um experimento foi conduzido onde o número de folhas, comprimento de parte aérea, raiz e total foram mensurados. Para cada variável, reamostragens com reposição foram realizadas em cenários amostrais de 1, 2, ..., 100 mudas por unidade experimental e o tamanho de amostra foi definido para os componentes de variância por meio de modelos de Schumacher e pontos de máxima curvatura. Os quadrados médios da análise de variância sofrem interferência direta do número de mudas amostradas. A amostragem de 16 mudas por unidade experimental é suficiente para estimar a análise de variância de forma confiável, promovendo satisfatórios ganhos de precisão ao comparar-se com a amostragem de apenas uma muda por unidade experimental.

Brassavola tuberculata Hook: in vitro growth and ex vitro establishment as a function of the micropropagation system and sucrose / Brassavola tuberculata Hook: crescimento in vitro e estabelecimento ex vitro em função do sistema de micropropagação e da sacarose

This study examines the in vitro growth and ex vitro establishment of Brassavola tuberculata in relation to the micropropagation system and sucrose concentration employed in the in vitro culture. A completely randomized experimental design was utilized, employing a 2 x 5 factorial arrangement. The experimental period began with seedlings cultivated in vitro for 180 days, which were subsequently transferred to Murashige and Skoog culture media containing sucrose concentrations of 0, 15, 30, 45, or 60 g L-1. The cultures were subjected to two micropropagation systems: conventional and gas exchange. After 90 days of in vitro cultivation, the plants were evaluated, transplanted into a substrate, and placed in a screened nursery for ex vitro cultivation. After 300 days of ex vitro cultivation, the survival and initial characteristics of the plants were assessed. The micropropagation system allowing gas exchange and sucrose concentrations up to 30 g L-1 enhanced the shoot and root growth of in vitro propagated plants. No noticeable anatomical differences were observed after 90 days of in vitro culture among the different sucrose concentrations and micropropagation systems used. In the ex vitro establishment, irrespective of sucrose concentration, the micropropagation system facilitating gas exchange positively influenced all evaluated characteristics.

Objetivou-se com este trabalho avaliar o crescimento in vitro e estabelecimento ex vitro de Brassavola tuberculata em função do sistema de micropropagação e da concentração de sacarose utilizados no cultivo in vitro. Foi utilizado o delineamento inteiramente casualizado e os tratamentos arranjados em esquema fatorial 2 x 5. Para o início do período experimental, foram utilizadas plântulas cultivadas in vitro por 180 dias, sendo transferidas para meios de cultivo Murashige e Skoog contendo 0, 15, 30, 45 ou 60 g L-1 de sacarose, e as culturas submetidas a dois sistemas de micropropagação: convencional ou com troca gasosa. Após 90 dias de cultivo in vitro, as plantas foram avaliadas e na sequência plantadas em substrato e acondicionadas em viveiro telado para o cultivo ex vitro. Após 300 dias de cultivo ex vitro, as plantas foram avaliadas quanto à sobrevivência e às mesmas características iniciais. A utilização do sistema de micropropagação que permite trocas gasosas, em conjunto com concentrações de sacarose de até 30 g L-1, proporcionou aumento no crescimento de parte aérea e do sistema radicular das plantas propagadas in vitro. As diferentes concentrações de sacarose e os sistemas de micropropagação utilizados não apresentaram diferenças anatômicas perceptíveis aos 90 dias de cultivo in vitro. Já no estabelecimento ex vitro, independente da utilização de sacarose, o sistema de micropropagação que permite trocas gasosas influenciou positivamente todas as características avaliadas.

Effect of Salinity and Silicon Doses on Onion Post-Harvest Quality and Shelf Life.

Salt stress during pre-harvest limits the shelf life and post-harvest quality of produce; however, silicon nutrition can mitigate salt stress in plants. Thus, we evaluated the effects of salinity and fertilization with Si, in pre-harvest, on the morpho-physiological characteristics of onion bulbs during shelf life. The experiment was set up in randomized complete blocks, with treatments arranged in split-split plots. The plots had four levels of electrical conductivity of irrigation water (0.65, 1.7, 2.8, and 4.1 dS m-1). The subplots had five fertilization levels with Si (0, 41.6, 83.2, 124.8, and 166.4 kg ha-1). The sub-sub plots had four shelf times (0, 20, 40, and 60 days after harvest). Irrigation water salinity and shelf time reduced firmness and increased the mass loss of onion bulbs during shelf life. Salt stress reduced the contents of sugars and total soluble solids of onion bulbs during storage; however, Si supply improved the contents of these variables. Salinity, Si supply, and shelf time increased the concentrations of pyruvic and ascorbic acids in onion bulbs during shelf life. Si doses between 121.8 and 127.0 kg ha-1 attenuated the impacts caused by moderate salinity, increasing the synthesis of metabolites and prolonging the onion bulbs' shelf life.

Risk evaluation of occupational exposure of southern Brazilian flower farmers to pesticides potentially leading to cholinesterase inhibition and metals exposure.

This work presents a frequency matched observational study comparing flower farmers exposed to pesticides and unexposed individuals as controls. All subjects were interviewed before plasma and urine collection. Manganese and Zinc were measured in theses samples by using dynamic reaction cell inductively coupled mass spectrometry. Cholinesterase activity was analyzed through spectrophotometry by using a modified version of the Ellman method. Seventy-eight percent of subjects reported occupational contact with pesticides, from which 37% reported exposure for over 9 years. Flower farms farmers had increased odds of having headache and irritability, respectively, by factors of 6.2 and 2.4 than the control subjects. While the odds of exposed subjects to have insomnia was smaller than control subjects by a factor of 0.34. Exposure to pesticides had a significant effect regarding the plasmatic plasma and urinary manganese levels and whole blood cholinesterase activity (p < 0.05). High levels of plasma and urinary manganese, as well as cholinesterase inhibition in whole blood, were evident in the flower farmers who participated in the study.

Horticultura terapêutica em um grupo de reabilitação da dependência química no Brasil / Therapeutic Horticulture in a Rehabilitation Group for Chemical Dependency in Brazil / Horticultura terapéutica en un grupo de rehabilitación de la dependencia química en Brasil

A prática da horticultura para benefício terapêutico é utilizada nas abordagens clínicas, que demonstram a melhoria da qualidade de vida e a redução dos índices de estresse biológico, como uma modalidade de Reabilitação Baseada na Comunidade (rbc). Este documento avalia a implementação de um projeto de economia solidária no contexto de um grupo de reabilitação para pessoas com dependência química. Trata-se de um estudo de avaliação qualitativa da implementação de tecnologias sociais (quintais produtivos), baseado no método da inserção ecológica, em um grupo de reabilitação e pre-venção terciária a dependência química de um Centro de Atenção Psicossocial no Brasil. Os participantes foram quinze pessoas, das quais doze eram do sexo masculino e três do sexo feminino, com idades entre 30 e 60 anos. Foi realizada análise documental dos prontuários do serviço, diário de campo, fotografias e filmagens das oficinas, reuniões, visitas domiciliares, visitas técnicas e dos mutirões. Os dados foram analisados seguindo os critérios da Avaliação Multicultural: Dimensionamento Dinâmico Individual e Contextual. Os resultados indi-caram que a implementação dos quintais produtivos fortaleceu os vínculos familiares e institucionais, por meio da rede de apoio construída em torno do projeto. Concluise que os quintais produtivos são eficientes para a geração de renda, segurança alimentar e nutricional e ações de ressocialização como uma estratégia terapêutica complementar de RBC.

Horticulture for therapeutic benefit is used in clinical approaches has, demonstrated improvements in the quality of life and the reduction of biological stress indexes, as a modality of Community-Based Rehabilita-tion (cbr). This paper evaluates the implementation of a solidarity economy project in the context of a rehabili-tation group for people with chemical dependency. This was a qualitative evaluation study of the implementation of social technologies (productive backyards), based on the ecological engagement method in a rehabilitation and tertiary prevention group of chemical dependency of a psychosocial care center in Brazil. The participants were fifteen people, twelve of whom were male and three female, aged between 30 and 60 years. Documental analyses of the records of the service, field diary, and photographs and filming of the workshops, meetings, home visits, technical visits, and community meetings were performed. The data were analyzed following the criteria of the Multicultural Evaluation: Dynamic Individual and Contextual Dimensioning. The results indicated that the implementation of the productive gardens strengthened family and institutional links through the support network built around the project. It is concluded that the productive backyards are efficient for income generation, food and nutritional security, and resocialization actions as a complementary thera-peutic strategy of CBR

La práctica de la horticultura para el beneficio terapéutico se utiliza en enfoques clínicos que demuestran la mejora de la calidad de vida y la reducción de los índices de estrés biológico, como una modalidad de rehabilitación basada en la comunidad (rbc). Este trabajo evalúa la implementación de un proyecto de economía solidaria en el contexto de un grupo de rehabilitación para personas con dependencia química. Se trata de un estudio de evaluación cualitativa de la implementación de tecnologías sociales (patios productivos), basado en el método de inserción ecológica en un grupo de rehabilitación y prevención terciaria de la dependencia química de un centro de atención psicosocial en Brasil. Participaron 15 personas, 12 de las cuales eran hombres y 3 mujeres, con edades comprendidas entre los 30 y los 60 años. Se realizó un análisis documental de los registros del servicio, el diario de campo, las fotografías y la filmación de los talleres, las reuniones, las visitas domiciliarias, las visitas técnicas y las reuniones comunitarias. Los datos se analizaron siguiendo los criterios de la Evaluación multicultural: dimensionamiento dinámico individual y contextual. Los resultados indicaron que la puesta en marcha de los huertos productivos fortaleció los vínculos familiares e institucionales, a través de la red de apoyo construida en torno al proyecto. Se concluye que los patios productivos son eficientes para la generación de ingresos, la seguridad alimentaria y nutricional y acciones de resocialización como estrategia terapéutica complementaria de la RBC

What is the best way to define sample size for cauliflower seedlings? / Qual é a melhor maneira para definir o tamanho amostral para mudas de couve-flor?

This study compared four methods for defining the ideal sample size per experimental unit to estimate the overall experimental mean for the total length, shoot length, root length, and the number of leaves of cauliflower seedlings. An experiment was carried out where the number of leaves, shoot, root, and total length were measured, and the general, perpendicular distance, linear response plateau, and spline methods were tested. While the general method may under or overestimate sample size and the sampling of 10 seedlings suggested by the spline method is still too far from the stabilization point of the curve, the perpendicular distance and linear plateau response methods are recommended to obtain results corresponding to narrower confidence interval widths. Therefore, according to the perpendicular distance method, at least 15 seedlings per experimental unit are required to estimate the overall experimental mean of cauliflower seedlings reliably for the traits here measured.

Este estudo comparou quatro métodos para definir o tamanho amostral ideal por unidade experimental para estimar a média experimental geral para o comprimento total, comprimento de parte aérea, comprimento de raiz e número de folhas de mudas de couve-flor. Um experimento foi conduzido no qual foram medidos o número de folhas, o comprimento total, de parte aérea e de radícula, e foram testados os métodos: geral, de distâncias perpendiculares, resposta linear platô e spline. Enquanto o método geral pode sub ou superestimar o tamanho amostral e a amostragem de 10 mudas sugerida pelo método spline ainda se encontra muito distante do ponto de estabilização da curva, os métodos de distâncias perpendiculares e resposta linear platô são recomendados por obterem resultados que corresponderam a amplitudes de intervalos de confiança menores. Portanto, de acordo com o método de distâncias perpendiculares, pelo menos 15 mudas por unidade experimental são necessárias para estimar a média experimental geral de mudas de couve-flor confiavelmente para as variáveis aqui mensuradas.

Impact of biostimulant and saline water on cape gooseberry (Physalis peruviana L.) in Brazil.

Production of Physalis peruviana L. has gained prominence in Northeastern Brazil. However, salinity limits the crop development in the Brazilian semiarid. Thus, this research aimed to evaluate the application of Acadian® biostimulant as mitigant of the deleterious effects of salinity on growth and gas exchange of P. peruviana plants. The experiment was combining different electrical conductivity of irrigation water (0.50, 1.23, 3.00, 4.44, and 5.50 dS m-1) and biostimulant doses (0.00, 1.45, 5.00, 8.55, and 10.00 mL L-1). The main variables evaluated were plant height, stem diameter, number of leaves, root length, leaf area, specific leaf area, leaf area ratio, absolute and relative growth rate for plant height, and gas exchange. Experimental results showed that an increase in electrical conductivity of irrigation water had negatively affected the growth components and gas exchange in P. peruviana. Also, the application of seaweed-based biostimulant improves the photosynthetic capacity (43.3%), reduces transpiration rate (26.5%) and water loss by this process, further it attenuated the deleterious effects of salinity on specific leaf area, leaf area ratio, and stomatal conductance. To further elucidate the effectiveness of biostimulant application as a mitigant of salt stress, research aimed at the biochemical and enzyme activities of the plant's antioxidant system should be conducted to better understand this process.

Lâminas de irrigação e hidrogel nas taxas de crescimento e produção de tomateiro / Irrigation depths and hydrogel on tomato growth and production rates / Láminas de riego e hidrogel en las tasas de crecimiento y producción de tomate

O tomateiro é uma das hortaliças de maior importância econômica a nível mundial. No entanto, sua produção pode ser limitada por diversos fatores, sendo o manejo da água o principal fator limitante. Dessa forma, o uso de tecnologias que melhorem a eficiência no uso da água é de extrema importância, destacando-se entre estas o uso de hidrogel. Nesse sentido, objetivou-se nesse trabalho avaliar as taxas de crescimento e produção do tomateiro sob lâminas de irrigação e volumes de hidrogel. O experimento foi conduzido em esquema fatorial 3x4, em blocos ao acaso com quatro repetições, sendo os fatores: três volumes de hidrogel previamente hidratado (0, 50 e 100 ml por planta); e 4 lâminas de irrigação (40, 60, 80 e 100% da evapotranspiração da cultura). Foram avaliadas as taxas de crescimento absoluto e relativo da altura de planta e diâmetro do caule, massa média dos frutos e a produtividade por planta. Os resultados evidenciaram que a redução das lâminas de irrigação levou a redução linear das taxas de crescimento absolutas e relativas de altura e diâmetro. Perante essas mesmas condições, também houve redução da massa média dos frutos e da produtividade por planta. O uso de hidrogel não afetou nenhuma das características avaliadas, dessa forma, recomenda-se a sua não utilização nas condições desse estudo. Indica-se a utilização da lâmina de reposição de 100% da ETc.(AU)

Tomato is one of the most economically relevant vegetables worldwide. However, its production can be limited by several factors, with water management being the main limiting factor. Thus, the use of technologies that improve efficiency in the use of water are extremely important, with emphasis on the use of hydrogel. In this sense, the objective of this study was to evaluate the growth and production rates of tomato under irrigation depths and hydrogel volumes. The experiment was carried out in a 3x4 factorial scheme, in randomized blocks with four replications, with the following factors: three volumes of previously hydrated hydrogel (0, 50 and 100 ml per plant); and 4 irrigation depths (40, 60, 80 and 100% evapotranspiration of the crop). The absolute and relative growth rates of plant height and stem diameter, average fruit mass, and productivity per plant were evaluated. The results showed that the reduction of irrigation depths led to a linear reduction in absolute and relative growth rates in both height and diameter. Under these same conditions, there was also a reduction in the average fruit mass and productivity per plant. The use of hydrogel did not affect any of the evaluated characteristics; therefore, it is recommended not to use it under the conditions of this study. It is recommended to use the 100% ETc replacement blade.(AU)

El tomate es una de las hortalizas de mayor importancia económica a nivel mundial. Sin embargo, su producción puede verse limitada por varios factores, siendo la gestión del agua el principal factor limitante. Por ello, el uso de tecnologías que mejoren la eficiencia en el uso del agua es de suma importancia, con énfasis en el uso de hidrogel. En ese sentido, el objetivo de este estudio fue evaluar las tasas de crecimiento y producción de tomate en láminas de riego y volúmenes de hidrogel. El experimento se realizó en un esquema factorial 3x4, en bloques al azar con cuatro repeticiones, siendo los factores: tres volúmenes de hidrogel previamente hidratado (0, 50 y 100 ml por planta); y 4 láminas de riego (40, 60, 80 y 100% evapotranspiración del cultivo). Se evaluaron las tasas de crecimiento absoluto y relativo de la altura de la planta y el diámetro del tallo, la masa promedio de frutos y la productividad por planta. Los resultados mostraron que la reducción de las láminas de riego condujo a una reducción lineal en las tasas de crecimiento absoluto y relativo en altura y diámetro. En estas mismas condiciones, también se redujo la masa media de frutos y de la productividad por planta. El uso de hidrogel no afectó ninguna de las características evaluadas, por lo que se recomienda no utilizarlo en las condiciones de ese estudio. Se recomienda utilizar la lámina de repuesto del 100% del ETc.(AU)

Machine learning models as an alternative to determine productivity losses caused by weeds.

BACKGROUND: Weed control can be economically viable if implemented at the necessary time to minimize interference. Empirical mathematical models have been used to determine when to start the weed control in many crops. Furthermore, empirical models have a low generalization capacity to understand different scenarios. However, computational development facilitated the implementation of supervised machine learning models, as artificial neural networks (ANNs), capable of understanding complex relationships. The objectives of our work were to evaluate the ability of ANNs to estimate yield losses in onion (model crop) due to weed interference and compare with multiple linear regression (MLR) and empirical models. RESULTS: MLR constructed from non-destructive and destructive methods show R2 and root mean square error (RMSE) values varying between 0.75% and 0.82%, 13.0% and 19.0%, respectively, during testing step. The ANNs has higher R2 (higher than 0.95) and lower RMSE (less than 6.95%) compared to MLR and empirical models for training and testing steps. ANNs considering only the coexistence period and system have similar performance to MLR models. However, the insertion of variables related to weed density (non-destructive ANN) or fresh matter (destructive ANN) increases the predictive capacity of the networks to values close to 99% correct. CONCLUSION: The best performing ANNs can indicate the beginning of weed control since they can accurately estimate losses due to competition. These results encourage future studies implementing ANNs based on computer vision to extract information about the weed community.

Landscape service flow dynamics in the metropolitan area of Córdoba (Argentina).

Human decisions, policies, and management strategies play an important role in structuring landscape patterns in a metropolitan area. Land-use/land-cover (LULC) changes can be considered probably the most important factor affecting the environment and the maintenance of landscape service flow. In particular, processes such as agricultural intensification, deforestation, urbanization and industrialization affect landscape heterogeneity in terms of composition and configuration. However, the multifunctional aspect of LULC as well as traditional agricultural practices can contribute to the maintenance of landscape service flow. This research aims to analyze and assess: (1) LULC dynamics and change from 1988 to 2019 within the metropolitan area of Córdoba (Argentina); (2) the effect of this change on landscape composition and configuration; (3) the flow of landscape services from 1988 to 2019, with the identification of hot-spots of landscape service provision. To analyze LULC dynamics and change within the study area, three Landsat images were utilized, while change detection analysis has been performed to identify the areas most affected by changes, the spatial distribution of change and the change trajectories of LULC classes in terms of landscape composition and configuration. Finally, the valuation of landscape service flow has been carried out by placing an economic value on the LULC classes, through the use of proxies. LULC pattern change has resulted in the expansion of extensive agriculture. The total variation from 1988 to 2019 has highlighted a significant reduction of Horticulture, Forests, and Grasslands, which have been converted into other classes (Urban and Extensive Agriculture). This conversion of LULC classes has had profound effects on landscape service flow, which guarantees the well-being of local communities. This research has contributed to the knowledge of where the hot-spots of landscape service' provision are located by helping landscape managers to identify suitable local policies able to preserve them, thus avoiding their loss, and enhancing landscape integrity, functionality, and resilience.

Light sources on the germination and initial in vitro establishment of Schomburgkia crispa Lindl., a species of the Brazilian Cerrado / Fontes de luz na germinação e estabelecimento inicial in vitro de Schomburgkia crispa Lindl. uma espécie do Cerrado brasileiro

ABSTRACT: Light is one of the factors that influence the germination and initial establishment of orchids under in vitro cultivation. This study evaluated the effect of different light sources on these stages in in vitro cultivation of Schomburgkia crispa Lindl. After sowing in an aseptic environment, we stored the cultures in a screened greenhouse (natural light) or in a growth room with the following light sources: 3,000 K yellow LED; 6,500 K white LED [1]; 6,500 K white LED [2]; or 6,500 K white fluorescent lamp (control). We assessed germination percentage and initial seedling establishment at 45 and 90 days after sowing. Light did not influence the germination of S. crispa. However, the use of 3,000 K LED provided a faster initial establishment of S. crispa when compared to the other light sources, also presenting lower seedling mortality. Thus, the light source 3,000 K LED is a potential substitute for the 6,500 K fluorescent lamps and LEDs used in growth rooms in in vitro culture laboratories.

RESUMO: A luz é um dos fatores que influenciam a germinação e o estabelecimento inicial no cultivo in vitro de orquídeas. Assim, objetivou-se avaliar o efeito de diferentes fontes de luz na germinação e no estabelecimento inicial in vitro de Schomburgkia crispa Lindl. Após semeadura em ambiente asséptico, as culturas foram acondicionadas em viveiro telado (luz natural) ou em sala de crescimento nas seguintes fontes luminosas: LEDs amarelo 3.000 K, branco 6.500 K [1], branco 6.500 K [2] ou lâmpada fluorescente branca 6.500 K (controle). Aos 45 e 90 dias após a semeadura foi avaliada a porcentagem de germinação e o estabelecimento inicial dos propágulos. A luz não influenciou a germinação das sementes de S. crispa, mas a utilização do LED 3.000 K proporcionou estabelecimento inicial de S. crispa em menor período e com menor mortalidade das plântulas, quando comparado com as demais fontes de luz utilizadas. A fonte de luz LED 3.000 K pode ser indicada como um substituto potencial para as lâmpadas fluorescentes e LEDs 6.500 K, utilizadas em salas de crescimento em laboratórios de cultivo in vitro.

Light sources on the germination and initial in vitro establishment of Schomburgkia crispa Lindl., a species of the Brazilian Cerrado / Fontes de luz na germinação e estabelecimento inicial in vitro de Schomburgkia crispa Lindl. uma espécie do Cerrado brasileiro

Light is one of the factors that influence the germination and initial establishment of orchids under in vitro cultivation. This study evaluated the effect of different light sources on these stages in in vitro cultivation of Schomburgkia crispa Lindl. After sowing in an aseptic environment, we stored the cultures in a screened greenhouse (natural light) or in a growth room with the following light sources: 3,000 K yellow LED; 6,500 K white LED [1]; 6,500 K white LED [2]; or 6,500 K white fluorescent lamp (control). We assessed germination percentage and initial seedling establishment at 45 and 90 days after sowing. Light did not influence the germination of S. crispa. However, the use of 3,000 K LED provided a faster initial establishment of S. crispa when compared to the other light sources, also presenting lower seedling mortality. Thus, the light source 3,000 K LED is a potential substitute for the 6,500 K fluorescent lamps and LEDs used in growth rooms in in vitro culture laboratories.(AU)

A luz é um dos fatores que influenciam a germinação e o estabelecimento inicial no cultivo in vitro de orquídeas. Assim, objetivou-se avaliar o efeito de diferentes fontes de luz na germinação e no estabelecimento inicial in vitro de Schomburgkia crispa Lindl. Após semeadura em ambiente asséptico, as culturas foram acondicionadas em viveiro telado (luz natural) ou em sala de crescimento nas seguintes fontes luminosas: LEDs amarelo 3.000 K, branco 6.500 K [1], branco 6.500 K [2] ou lâmpada fluorescente branca 6.500 K (controle). Aos 45 e 90 dias após a semeadura foi avaliada a porcentagem de germinação e o estabelecimento inicial dos propágulos. A luz não influenciou a germinação das sementes de S. crispa, mas a utilização do LED 3.000 K proporcionou estabelecimento inicial de S. crispa em menor período e com menor mortalidade das plântulas, quando comparado com as demais fontes de luz utilizadas. A fonte de luz LED 3.000 K pode ser indicada como um substituto potencial para as lâmpadas fluorescentes e LEDs 6.500 K, utilizadas em salas de crescimento em laboratórios de cultivo in vitro.(AU)

Challenges of organic agriculture for the production of composts and vermicompost for the production of medicinal plants: a socioeconomic demand / Desafios da agricultura orgânica na produção de composto e vermicomposto na produção de plantas medicinais: uma demanda socioeconômica

Although the demand for organic fertilizers in agriculture is growing, it remains incipient in some production sectors, such as medicinal plant production, which does not possess specific technology for its development. Solid residues are highly contaminant to water sources, soil, populations and biodiversity but can potentially be used to produce organic composts and vermicompost, such production not only enables nutrient recycling but also acts on soil conditioning, increasing soil organic matter and improving its physical, chemical and biological characteristics, as well as strengthening organic production with an emphasis on medicinal plant production. In this context, recommendations for and applications of organic fertilizers available in the market were reviewed; in addition, the imminent socioeconomic demand for organic compost and vermicompost production was contextualized based on residues from coffee and sugarcane production and cattle farming for application to the medicinal plant production chain. It is concluded that although these sectors produce a considerable amount of residues, they are not being reused in formulation of organic composts and vermicompost, and commercial organic fertilizers recommended for medicinal plant production were not found. Thus, the formulation of vermicomposting and composting from the reuse of agricultural residues, are potential social, economic technologies and tools to be valued and disseminated to traditional and family farmers. (AU)

Embora a demanda por fertilizantes orgânicos na agricultura seja crescente, ela ainda é incipiente em alguns setores produtivos, como a produção de plantas medicinais, que não possui tecnologia específica para seu desenvolvimento. Os resíduos sólidos são altamente contaminantes para fontes de água, solo, populações e biodiversidade, mas podem ser potencialmente utilizados para a produção de compostos orgânicos e vermicomposto, tal produção não só possibilita a reciclagem de nutrientes, mas também atua no condicionamento do solo, aumentando a matéria orgânica do solo e melhorando seu aspecto físico, químico e características biológicas, além do fortalecimento da produção orgânica com ênfase na produção de plantas medicinais. Nesse contexto, foram revisadas as recomendações e aplicações dos fertilizantes orgânicos disponíveis no mercado; além disso, a iminente demanda socioeconômica pela produção de composto orgânico e vermicomposto foi contextualizada a partir dos resíduos da produção de café, cana-de-açúcar e pecuária para aplicação na cadeia produtiva de plantas medicinais. Conclui-se que embora esses setores produzam uma quantidade considerável de resíduos, eles não estão sendo reaproveitados na formulação de compostos orgânicos e vermicomposto, e não foram encontrados fertilizantes orgânicos comerciais recomendados para a produção de plantas medicinais. Sendo assim, a formulação de vermicompostagem e compostagem a partir do reaproveitamento de resíduos agropecuários, são potenciais tecnologias sociais, econômicas e ferramentas a serem valorizadas e disseminadas para os agricultores tradicionais e familiares. (AU)

Morphological and anatomical insights into de novo shoot organogenesis of in vitro 'Delite' rabbiteye blueberries.

Blueberries are valued for their taste and their high nutritional benefits, including their antioxidant and anti-inflammatory properties. In vitro culturing is an alternative method for clonal propagation, and has been used in many biotechnological studies. Most blueberry research is concentrated on highbush and lowbush taxa (Vaccinium corymbosum and Vaccinium angustifolium respectively), with only limited investigations of rabbiteye cultivars (Vaccinium virgatum) that are more suitable for subtropical climates and regions with warmer winters as a result of climate change. There is therefore a need to determine in vitro protocols for that species and group of cultivars. We examined here adventitious shoot regeneration in the 'Delite' rabbiteye blueberry cultivar. Leaf explants were cultured in vitro in Woody Plant Medium (WPM), and the effects of different thidiazuron (TDZ) concentrations, the orientation of the leaf (adaxial or abaxial surface in contact with the medium), and two portions of the leaf segment (basal or apical) were examined. De novo shoot development was studied using light and scanning electron microscopy. All concentrations of TDZ used showed similar survival and regeneration rates; 0.5 µM TDZ showed high efficiency in regenerating adventitious shoots (100%, with 57 adventitious shoots/explant), as did the adaxial surface in contact with the medium using either the apical or the basal portion of the leaf (97% shoot regeneration, 47.5 adventitious shoots/explant). Anatomical analyses showed direct and indirect organogenesis. The shoots developed leaf primordia with stomata, trichomes, and well-developed vascular tissues, with further elongation and rooting of the plants. We therefore describe here a high-efficiency regeneration method through de novo shoot organogenesis using TDZ in foliar explants of rabbiteye blueberry, with direct and indirect organogenesis.