Acúmulo de silício em couve-flor cultivada em ambiente protegido com diferentes condições de disponibilidade hídrica

The objective of this work was to determine the accumulation of silicon in the plant components of cauliflower (Brassica oleracea var. botrytis) grown with different levels of water replacement and rates of Si. The experimental design was a randomized complete block with three water replacement conditions (40, 70, and 100% evapotranspiration), four Si rates (0, 50, 100, and 150 kg ha-1), and four replicates. Daily evapotranspiration was determined with constant water table lysimeters, with water replacement by a drip system. As a source of Si, silicon oxide was applied three times in the crop cycle – at the initial, intermediate, and final development stages of the plant. At the end of the cycle, samples of plant tissue (root, stem, leaves, and inflorescence) and soil were collected to determine Si by spectrometry. The Si content in the soil was not influenced by water replacement, only by silicate fertilization. The silicon applied to the soil increased the content of the element in the plant components, especially in the roots. Water replacement influences the accumulation of Si in cauliflower plant tissues, with lower amounts of the element under water deficit conditions.O objetivo deste trabalho foi determinar o acúmulo de silício nos componentes vegetais de couve-flor (Brassica oleracea var. botrytis) cultivada com diferentes níveis de reposição hídrica e doses de Si. O delineamento experimental foi em blocos ao acaso, com três condições de reposição hídrica (40, 70 e 100% da evapotranspiração), quatro doses de Si (0, 50, 100 e 150 kg ha-1) e quatro repetições. Determinou-se a evapotranspiração diária com lisímetros de lençol freático de nível constante, com reposição da água por sistema de gotejamento. Como fonte de Si, o óxido de silício foi aplicado três vezes no ciclo da cultura – nos estágios inicial, intermediário e final de desenvolvimento da planta. Ao final do ciclo, foram coletadas amostras de tecido vegetal (raiz, caule, folhas e inflorescência) e solo para determinação de Si por espectrometria. O teor de Si do solo não foi influenciado pela reposição hídrica, apenas pela adubação silicatada. O silício aplicado no solo aumentou o teor do elemento nos componentes da planta, principalmente nas raízes. A reposição hídrica influencia o acúmulo de Si nos tecidos da planta de couve-flor, com menor teor do elemento em condições de deficit hídrico

SPAD INDEX AS AN INDIRECT ESTIMATE OF CHLOROPHYLL CONTENT IN OKRA PLANTS

A clorofila, molécula responsável pela atividade fotossintética das plantas, pode ser quantificada por métodos diretos e indiretos. O objetivo do estudo foi relacionar os resultados do conteúdo de clorofila obtidos por diferentes métodos de determinação em folhas de quiabo. Foi estimado o conteúdo de clorofila através do índice SPAD (não-destrutivo) e da extração dos pigmentos foliares com acetona (destrutivo). As análises foram realizadas em folhas de quiabo (cultivar Santa Cruz 47) do terço médio de plantas no estágio reprodutivo com coloração variando de amarela a verde escuro, em condição de sequeiro. Determinações pelo método não destrutivo foram realizadas com equipamento SPAD-502 e as determinações por método destrutivo foram realizadas por espectrometria, utilizando acetona como extrator. Foi realizada análise descritiva, correlação e regressão nos dados. O índice SPAD variou de 20,93 a 49,03, e apresentou correlação linear com o conteúdo de pigmentos foliares. O índice SPAD apresentou correlação positiva com os teores de clorofila b e clorofila total, entretanto para o conteúdo de clorofila a foi observado relação negativa. A variação do conteúdo de carotenoides não apresentou relação direta com o índice SPAD. A estimativa do conteúdo de clorofila por método não destrutivo apresenta relação direta com o conteúdo absoluto em folhas de quiabo.Chlorophyll, the molecule responsible for the photosynthetic activity of plants, can be quantified by direct and indirect methods. The study aimed to relate the results of chlorophyll content obtained by different determination methods in okra leaves. Chlorophyll content was estimated using the SPAD index (non-destructive) and leaf pigments extraction with acetone (destructive). Analyzes were carried out on okra leaves (cultivar Santa Cruz 47) from the middle third of plants during the reproductive stage, varying colors from yellow to dark green under rainfed conditions. Determinations by the non-destructive method were conducted with SPAD-502 equipment, and determinations by the destructive way were carried out by spectrometry. Descriptive analysis, correlation, and regression were performed on the data. SPAD index ranged from 20.93 to 49.03 and showed a linear correlation with leaf pigments content. SPAD index showed a positive correlation with chlorophyll b and total chlorophyll contents. However, a negative relationship was observed for chlorophyll a content. Variation in carotenoid content was not directly related to the SPAD index. Estimating chlorophyll content by the non-destructive method directly correlates with the absolute content in okra leaves

Efeito das condições de secagem e armazenamento sobre a qualidade do café natural e despolpado

The objective of the work was to evaluate alterations in the quality of natural and washed coffee under different drying conditions (coffee drying yard, temperature of 40ºC and 60ºC) and storage conditions at 60% of relative humidity, with controlled temperature of 23ºC, at 90 and 180 days. The work was carried out in the Engineering Department and in the Coffee Post-Harvest Technology Pole of the Federal University of Lavras. The manual harvest of the coffee (Coffea arabica L.), Topázio variety, was selective. Part of the coffee was pulped and the other part was processed in the natural form. A portion of each type of coffee was submitted to drying on the yard and two other samples were processed in a mechanical dryer, at temperatures of 40ºC and 60ºC. After drying, the coffee was stored in an air-tight room, in which a stable relative humidity of 60% was maintained with a solution of magnesium nitrate. Quality evaluation, sensorial analyses, electric conductivity and potassium leaching tests, total titrable acidity, fatty acidity and total and reducing sugars determinations were carried out. The results showed that the coffee dried at 60ºC, after 90 days storage, presented the poorest quality. The physical-chemical evaluations of the drying and storage conditions showed that washed coffee presents better quality when compared to the product in its natural form.Objetivou-se com o presente trabalho avaliar as alterações na qualidade dos cafés natural e despolpado nas condições de secagem (terreiro, temperatura de 40ºC e 60ºC) e armazenamento de 60% de umidade relativa com temperatura controlada de 23ºC, aos 90 e 180 dias. O trabalho foi realizado no Departamento de Engenharia e no Pólo de Tecnologia em Pós-Colheita do Café da Universidade Federal de Lavras. A colheita manual do café (Coffea arabica L), variedade Topázio, foi seletiva. Parte do café foi despolpado e outra parte, processada de forma natural. Uma parcela de cada tipo de café foi submetida à secagem em terreiro e as outras duas, às temperaturas de 40ºC e 60ºC em secador mecânico. Depois da secagem, o café foi armazenado em ambiente hermético, mantendo-se constante a umidade relativa de 60%, com solução de nitrato de magnésio. Para avaliação da qualidade, foram realizados análise sensorial, testes de condutividade elétrica e lixiviação de potássio, determinações de acidez titulável total, acidez graxa, açúcares totais e redutores. Pelos resultados obtidos, conclui-se que os cafés submetidos à secagem com temperatura de 60ºC e armazenados a partir de 90 dias apresentaram as piores características de qualidade; as avaliações físico-químicas para as condições de secagem e armazenamento mostram que o café despolpado apresentou melhor qualidade, quando comparado com o produto na sua forma natural

DECOMPOSITION OF THE REMAINING STRAW DURING SOYBEAN GROWING IN THE MIDWESTERN PARANÁ, BRAZIL

Crop biomass plays an important role, especially in tropical and subtropical crops that adopt the no-tillage system, whose decomposition is related to material composition and environmental conditions. The objective of this work was to analyze the decomposition of straw remaining from autumn/winter crops in the development of soybean in succession in the Midwest region of Paraná. The experiment was conducted between 2019 and 2021 in a completely randomized design, with eight treatments (spontaneous, black oat, brachiaria, corn, wheat, oilseed radish, corn + brachiaria, and black oat + oilseed radish) and four replications. After autumn/winter cultivation, biomass samples were dried and placed in nylon bags, returning to the original plot during soybean sowing. The decomposition bags were collected in seven periods over 120 days, coinciding with the soybean cycle. The decomposition rate was analyzed by regression. The regression equations and the amount of biomass remaining from the autumn/winter seasons were determinate the half-file and the remaining mass on the soil surface at sowing and at 30, 60, 90, and 120 days after sowing. Biomass production and decomposition rate varied with the season, depending on environmental conditions. Wheat had the lowest decomposition rate with a half-life greater than 100 days. Intercropping crops reduce the decomposition rate.Crop biomass plays an important role, especially in tropical and subtropical crops that adopt the no-tillage system, whose decomposition is related to material composition and environmental conditions. The objective of this work was to analyze the decomposition of straw remaining from autumn/winter crops in the development of soybean in succession in the Midwest region of Paraná. The experiment was conducted between 2019 and 2021 in a completely randomized design, with eight treatments (spontaneous, black oat, brachiaria, corn, wheat, oilseed radish, corn + brachiaria, and black oat + oilseed radish) and four replications. After autumn/winter cultivation, biomass samples were dried and placed in nylon bags, returning to the original plot during soybean sowing. The decomposition bags were collected in seven periods over 120 days, coinciding with the soybean cycle. The decomposition rate was analyzed by regression. The regression equations and the amount of biomass remaining from the autumn/winter seasons were determinate the half-file and the remaining mass on the soil surface at sowing and at 30, 60, 90, and 120 days after sowing. Biomass production and decomposition rate varied with the season, depending on environmental conditions. Wheat had the lowest decomposition rate with a half-life greater than 100 days. Intercropping crops reduce the decomposition rate

Caracterização físico-química do composto fermentado Bokashi produzido em propriedade rural no sul do Brasil

Bokashi is fermented organic compost capable of improving the physical, chemical, and biological conditions of the soils. The compost action in the agricultural production system is influenced by its preparation, resulting in products with different physicochemical characteristics. The study aimed to characterize bokashi produced on-farm and compare it with commercial products. The produced composts in southern Brazil were obtained through efficient microorganisms (EM), collected in an area of permanent preservation, and kefir. Two commercial composts were used for comparison (Plantae FertTM and Bokashi Sementes BrasilTM). Physical characteristics related to apparent specific gravity, water content, and water retention capacity and chemical characteristics related to nutrient contents, pH, and electrical conductivity were analyzed. For the physical characteristics, the mean and standard deviation were determined. The data from chemical parameters were submitted to the analysis of variance, and the means were compared by the Tukey test with 5% significance. Bokashi produced on-farm and commercial Bokashi showed similar physical characteristics. Commercial bokashi composts showed higher contents of nutrients than the composts produced on-farm. The analyzed composts showed adequate physicochemical parameters, with no factors limiting their use in agriculture.    Bokashi é um composto orgânico fermentado capaz de melhorar as condições físicas, químicas e biológicas dos solos. A ação do composto no sistema de produção agrícola é influenciada pelo preparo, resultando em produtos com diferentes características físico-químicas. O objetivo do estudo foi caracterizar o Bokashi produzido em propriedade rural e comparar com produtos comerciais. Os compostos produzidos no sul do Brasil foram obtidos através de microrganismos eficientes (EM), coletados em área de preservação permanente, e kefir. Dois compostos comerciais foram utilizados para comparação (Plantae Fert® e Bokashi Sementes Brasil®). Foram analisadas características físicas relacionadas à massa específica aparente, teor de água e capacidade de retenção de água, características químicas relacionadas ao teor de nutrientes, pH e condutividade elétrica. Para as características físicas, foram determinados a média e o desvio padrão. Os parâmetros químicos foram submetidos à análise de variação e as médias comparadas pelo teste de Tukey com 5% de significância. O Bokashi produzido e comercial apresentaram características físicas semelhantes. Os compostos comerciais de Bokashi apresentaram características químicas superiores aos compostos produzidos na propriedade rural. Os compostos analisados apresentaram parâmetros físico-químicos adequados, não havendo fatores limitantes ao seu uso na agricultura

Leaf pigments in cauliflower cultivated with different water conditions and silicon applications

Environmental factors and crop management can influence the characteristics of plant morphology and physiology, altering photosynthetic efficiency and mass accumulation. The study aimed to analyze the contents of leaf pigments in cauliflower cultivated under different conditions of water availability and silicon (Si) applications. The experiment was carried out in a protected environment in the city of Maringá-PR. A randomized block design, in a 3x4 factorial scheme, with three replacement conditions [40, 70 and 100% of crop evapotranspiration (ETc)] and four Si doses (0, 50, 100 and 150 kg ha-1), with four repetitions. The cauliflower cultivation, cultivar Sharon, was carried out in dystroferric RED NITOSOL. Daily evapotranspiration was determined with a constant level water table lysimeter and water replacement was performed with drip irrigation. Si was applied in split doses in three applications (initial, intermediate and final phases). At flowering, leaf tissue from the upper third of the plant was collected, with pigment extraction performed with pure acetone and determination in a spectrophotometer. At harvest, the leaf area of ​​the plants was determined. Data were subjected to analysis of variance and regression analysis. Cauliflower crop under water-deficient reduces leaf area development and alters chloroplast pigments dynamics. Silicon use in the soil increases leaf development, chlorophyll a and b contents, and reduces carotenoids concentration. Under water stress conditions, silicon addition to the soil improves cauliflower performance

IRRIGATION WITH WATER DEFICIT APPLYING MAGNETIC WATER ON SCARLET EGGPLANT

The work aimed to evaluate the effect of irrigation with magnetically treated water on development, growth, and yield of the scarlet eggplant (Solanum gilo Raddi) cv. Morro Grande, in two growing seasons (autumn and spring). A completely randomized design in a 3x2 factorial scheme with three replications for the first growing season and 2x2 with five replications for the second growing season was used. Each experimental unit consisted of four plants spaced 0.75 m between plants and 1.00 m between rows. Factors consisted of irrigation using magnetically treated water, untreated water, three replacement of the crop evapotranspiration (50%, 75%, and 100% ETc) for the first growing season and two replacement of the crop evapotranspiration (75% and 100% ETc) for the second growing season. Stem diameter (millimeters), plant height (centimeters), shoot dry matter (grams), first flower and fruit (accumulated degree-days), number of fruits, fruit yield per plant (grams), and average fruit mass (grams) were evaluated. The water with magnetic treatment provided better results for the development variables, first flower, and first fruit in the second growing season. However, for the variables, stem diameter, plant height, shoot dry matter, fruit yield, and number of fruits, only the replacement irrigation depth factor obtained higher values for the 100% ETc than water-deficit treatments

GROWTH AND DEVELOPMENT OF BELL PEPPER CROP IRRIGATED WITH MAGNETICALLY-TREATED WATER

This study aimed to evaluate the benefits of irrigation with magnetically-treated water and replacement depths based on ETc, in plant growth and development of bell pepper grown in a protected environment in two cultivation seasons. The experiment was carried out in a protected environment, in the Centro Técnico de Irrigação (CTI), at Universidade Estadual de Maringá (UEM), in Maringá - PR. Two experiments were performed: summer (2017-2018) and winter-spring (2018). The experimental design adopted was randomized blocks in factorial scheme 3 x 2 (six treatments) with four replications in the summer season and 2 x 2 (four treatments) with six replications in the winter-spring season. The first factor consisted of water replacement depths (50, 75 and 100% of the evapotranspiration of culture (ETc) in the summer season, and 75 and 100% ETc in the winter-spring season. The second factor was the application of water with and without magnetic treatment. Characteristics of growth (plant height, stem diameter, leaf area, and dry matter of stem, leaf, total, and root) and development (first flower and first fruit) were evaluated. Results showed that there was no significant interaction between the factors for the summer season. There were only isolated effects of replacement depths, and the 100% ETc had the highest values for the growth variables, independent of water treatment. The application of magnetically-treated water provided higher accumulation of dry matter (stem, total, and root) when irrigated with 75% ETc for the winter-spring season

YIELD AND ECONOMIC ANALYSIS OF CORN AND BRACHIARIA INTERCROPPING IN THE NORTHWESTERN PARANÁ

A consorciação de milho e Urochloa ruziziensis apresenta potencial para os sistemas de produção agrícola, permitindo a produção de grãos e biomassa remanescente. O estudo tem como objetivo avaliar a produtividade e a viabilidade econômica das modalidades de consórcio de milho e U. ruziziensis na região noroeste do Paraná. O experimento foi conduzido em Maringá-PR, em delineamento inteiramente casualizado com cinco tratamentos (milho solteiro; U. ruziziensis solteira; milho com U. ruziziensis na entre linha; milho com U. ruziziensis na mesma linha; milho com U. ruziziensis em linhas intercaladas) e quatro repetições. Foi analisado o desenvolvimento inicial e produtividade de grãos do milho, e produção de biomassa de milho e U. ruziziensis. Os dados foram submetidos a análise de variância e as médias comparadas pelo teste Tukey com significância de 5%. No desenvolvimento inicial das plantas de milho não houve diferença significativa em função da consorciação. U. ruziziensis em sistema consorciado apresentou redução na produção de biomassa. O cultivo em linhas intercaladas apresentou produtividade de grãos superior as demais modalidades de consorciação e semelhante ao cultivo de milho solteiro.The maize and Urochloa ruziziensis intercropping have potential use for agricultural production systems, allowing the production of grains and biomass. The study aims to evaluate the yield and economic viability of corn and U. ruziziensis intercropping modalities in the northwestern region of Paraná. The experiment was conducted in Maringá-PR in a completely randomized design with five treatments (single corn; single U. ruziziensis; U. ruziziensis between the corn rows; corn with U. ruziziensis in the same row; corn rows interspersed with U. ruziziensis rows) and four replicates. Initial development, grain yield of corn, and the production of biomass of corn and U. ruziziensis were evaluated. The data were submitted to analysis of variance. The means were compared by the Tukey test at 5% probability. In the initial development of corn plants, there was no significant difference due to intercropping. U. ruziziensis in the intercropped system had a reduction in biomass production. Intercropping with corn rows interspersed with U. ruziziensis rows had grain yield higher than other intercropping modalities and similar to single corn cultivatio