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

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

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

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

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

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

Alternativas para secagem de sementes: consumo energético do sistema de qualidade da semente de abóbora em função do processo de secagem / Seed drying alternatives: energy consumption of the pumpkin seed quality system as a function of the drying process

A semente de abóbora (Cucurbita pepo) é rica em vitamina E, proteínas, lipídeos e fibras insolúveis. O presente estudo teve como objetivo comparar o processo de três métodos de secagem em relação ao tempo de secagem das sementes de abóboras, à sua composição centesimal e efeitos sobre características físicas/fisiológicas. A matéria-prima com teor de água ±0,35 (bs) foi submetida à secagem em estufa a vácuo, com fluxo de ar aquecido e por liofilização até que a semente atingisse um teor de água ±0,08 (bs). Houve alteração significativa nos teores de proteína e lipídeos, porém, a fração de fibras nas sementes de abóbora não foi influenciada pelos processos de secagem. Enquanto o método em fluxo de ar aquecido apresentou menor tempo de secagem e menor efeito sobre a qualidade, o processo por condução causou danos oxidativos nos lipídeos e proteínas da semente de abóbora. As maiores velocidades de remoção de água foram detectadas nas sementes de menor densidade, onde através da razão de água, em função do tempo de secagem, demoraram menor intervalo de tempo para atingir o teor de água de equilíbrio. O método em estufa com fluxo de ar aquecido apresentou menor gasto energético. A técnica de secagem por estufa com circulação de ar quente apresentou elevada produção, menores perdas na qualidade da semente e menor consumo energético, enquanto o processo por liofilização elevado gasto de energia e tempo de secagem superior. O teste de condutividade elétrica diferenciou a qualidade das sementes de abóbora (Cucurbita pepo) destacando maior vigor às sementes secas com circulação de ar forçado e menor vigor nos lotes do processo a vácuo.

DETERRÊNCIA À ALIMENTAÇÃO E À OVIPOSIÇÃO DE Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) PELO USO PÓS VEGETAIS EM MILHO ARMAZENADO

Plants with insecticidal effect are among the alternatives as a tool to control the insect-pest of stored grains. The objective of this study was to characterize the efficiency of plant-based powders on Sitophilus zeamais insects in stored grains. Using fourteen plant species (Arnica montana Baccharis trimera Less., Coriandrum sativum L., Coffea arabica, Cymbopogon martini, Helianthus annuus, Lippia gracillis, Mentha pulegium L., Moringa oleífera, Nicotiana tabacum, Piper aduncum, Piper hispidinervum, Sesamum indicum and Vitis labrusca) obtained from tritured vegetable material, and compared with a control treatment. The experiment was carried out in a completely randomized design, with six replicates each treatment. In the tests, 0.5 g of the inert powders were mixed into the grains (50 g) of hybrid corn AS 1551 into plastic vials and infested with 10 emerged adult of S. zeamais. After 20 days of infestation, oviposition was evaluated and counts of emerged adults. At the end of the infestation period, evalued the dry weight of the insects, the weight of grains consumed and the period of development (egg-adult). Most of the vegetal powders presented effective action on the emerged insects. By the use of the powders it verified reduction in the ooposition, except for Vitis labrusca and Sesamum indicum whose egg numbers were higher than control, also had less effect on the development of caruncho larvae. The low weight of adults from corn kernels treated with Nicotiana tabacum powder suggests a reduction in feeding of S. zeamais larvae.Plantas com efeito inseticida apresentam-se entre as alternativas como ferramenta de controle dos insetos-praga de grãos armazenados. No presente estudo, objetivou-se caracterizar a eficiência dos pós de origem vegetal sobre Sitophilus zeamais em grãos armazenados. Foram avaliados 14 pós vegetais (Arnica montana Baccharis trimera Less., Coriandrum sativum L., Coffea arabica, Cymbopogon martini, Helianthus annuus, Lippia gracillis, Mentha pulegium L., Moringa oleífera, Nicotiana tabacum, Piper aduncum, Piper hispidinervum, Sesamum indicum e Vitis labrusca)  obtido de material vegetal triturado, e comparado com um tratamento controle. O experimento foi realizado em delineamento inteiramente casualizado, com seis repetições cada tratamento. Nos testes, 0,5 g dos pós inertes foram misturados aos grãos (50 g) de milho híbrido AS 1551 dentro de frascos plásticos, sendo infestados com 10 S. zeamais adultos emergidos. Após 20 dias da infestação avaliou-se a oviposição e iniciou-se a contagem de adultos emergidos. Ao fim do período de infestação, foi avaliado o peso seco dos insetos, o peso de grãos consumidos e o período de desenvolvimento (ovo-adulto). A maioria dos pós vegetais apresentou atuação efetiva sobre os insetos emergidos. Constatou-se nos pós testados redução na oviposição, exceto Vitis labrusca e Sesamum indicum cujo número de ovos foi superior ao controle, também apresentaram menor efeito sobre o desenvolvimento das larvas do caruncho. O baixo peso de adultos provenientes de grãos de milho tratados com pó de Nicotiana tabacum sugere a ocorrência de deterrência na alimentação das larvas de S. zeamais

Comparison of lots of pea seeds produced in northwest of Paraná

The establishment of the crop demands the use of seeds that allow the plants to perform better in adverse conditions. The study aimed to compare lots of pea seeds produced in the northwestern region of Paraná. The experiment was carried out in a completely randomized design with seven seed lots and four replications. The seeds were obtained in field production, with similar management conditions. The determination of the weight of a thousand seeds, water content, electrical conductivity, percentage of germination, fresh and dry mass of the aerial part and root of the seedlings performed. The data were subjected to analysis of variance and the means compared by the Tukey test with 5% significance. The physiological potential not directly related to the seed mass; of the pea lots produced under adverse conditions, lots L3 and L4 showed superior quality. The physiological tests of electrical conductivity and germination differentiated the quality of the seeds. According to the selection criteria, the seeds of four pea lots showed germination higher than 85%, being the seeds of the lot L3 and L4 presented superior quality

Physiological responses of oregano under different water management and application of fermented bokashi compost

Growing conditions such as water supply and soil fertility influence oregano morphological development and physiological responses. Our study aimed to analyse the physiological responses of oregano plants grown under different water conditions and bokashi application rates. The experiment was carried out in a greenhouse under a randomized block design and a 3 x 4 factorial scheme. Treatments encompassed three water replacement levels (60, 80, and 100% crop evapotranspiration - ETc) and four bokashi rates (0, 100, 200, and 300 g m-2), with five replications each. Oregano seedlings were transplanted and grown in a spacing of 0.3 m between plants and 1 m between bed rows. After 60 days, treatments were evaluated for photosynthetic rate (A), stomatal conductance (Gs), internal CO2 rate (Ci), transpiration (E), and water-use efficiency (WUE). Data underwent variance analysis by F-teste, multivariate analysis, and Pearson's linear correlation. Oregano physiological responses were significantly influenced by water replacement level and the application rate of fermented bokashi compost. The multivariate analysis allowed us to analyse the interaction effect between water replacement level and bokashi rate on photosynthesis, stomatal conductance, internal CO2, and transpiration