Abstract The present study consisted in optimizing the extractive method of polyphenols and total tannins of leaves of Syzygium cumini (L) Skeels assisted by microwaves to potentiate the antimicrobial activity of the dried extract of S. cumini against sensitive and resistant strains. A Box-Behnken design that consisted of 27 experimental runs coupled with a desirability function for multiple response optimization was employed to optimize the total polyphenols content and total tannins content. Antimicrobial sensitivity tests were evaluated by obtaining the minimum inhibitory concentration, minimum fungicidal concentration and minimum bactericidal concentration in 96-well petri dishes. The optimal extraction conditions were found to be 8 min of extraction, under 300 w of microwave power, using a 1:34 g/mL solid/solvent ratio and 38% of ethanol concentration as extraction solvent. The parameter with the greatest influence in the extraction was primarily the time, followed by the potency and proportion solid/solvent. This yielded a total polyphenol content of 87.37 ± 1.85 mg TAE g-1ext and a total tannin content of 79.68 ± 1.64 mg TAE g-1 ext. All tested microorganisms were sensitive to the extract, evidencing the effectiveness of the extraction method optimization.

Abstract Syzygium cumini L. Skeels belongs to Myrtaceae family. This species has been recognized by its antidiabetic, anti-inflammatory, and antimicrobial activities. Despite ever-increasing scientific interest for this species there is no pharmacopeia method for characterization and standardization of S. cumini yet. So, toward this aim, the objective of this work was to develop an efficient analytical methodology able to determine polyphenols and tannins content from leaves hydroethanolic extract of S. cumini using Folin-Ciocalteu method by ultraviolet absorption spectrophotometry (UV-Vis). The analytical methodology was developed for the first time in the literature for leaves of this specie shown to be fast and low-cost with results expressed through tannic acid equivalent (TAE). Moreover, the methodology presented selectivity with maximum absorption at 706 nm wavelength, linearity with R2>0.99; limit of detection 0.275 µg TAE mL-1 and 0.102 µg TAE mL-1; limit of quantification 1.046 µg TAE mL-1 and 0.912 µg TAE mL-1 for total polyphenols and total tannins, respectively. Furthermore, the methodology was accurate with recover value greater than 98%, as well as exact, reproductive, and robust with coefficient of variation values less than 15% for both compounds. All the results are found within the fixed limits according to RDC 166/2017.

O mercado de sementes está se tornando um mercado globalizado e esta globalização está ocorrendo muito rapidamente. Para competir favoravelmente neste novo mercado global de sementes, qualidade e custo são e serão certamente os pontos chaves do negócio. Sementes de alta qualidade só podem ser obtidas através de um rigoroso controle de todo o processo de produção, etapa por etapa desde o seu planejamento inicial até a sua entrega ao consumidor final. Isto requer ciência, tecnologia, conhecimento, experiência, bom gerenciamento e certamente, o mais importante, um absoluto e incondicional comprometimento com a qualidade. Nos últimos anos, um grande número de resultados de pesquisa têm sido publicados, particularmente sobre o uso de algumas técnicas baseadas na Reação da Polimerase em Cadeia do "DNA" (RAPD, microsatélites, AFLP) para a determinação da pureza genética em análise de sementes. Tanto quanto sabemos, não existe nenhuma companhia brasileira de sementes usando, em bases regulares, RAPD ou outras técnicas de marcadores moleculares na determinação da pureza genética na análise de sementes. A maior parte delas está utilizando caracteres morfológicos ou fisiológicos expressados pelas sementes, plântulas ou plantas adultas e/ou eletroforese de proteínas/isoenzimas de sementes ou plântulas para esta finalidade. Os principais motivos para esta realidade atual são: as técnicas para uso de marcadores moleculares baseados em DNA são relativamente novas; falta de técnicos/profissionais especializados para a utilização das mesmas, em carater de rotina; custo mais elevado/amostra quando comparado com a eletroforese de proteínas/isoenzimas.

Seed market is becoming global and globalization is growing very fast. To compete favourably in this new global seed world, quality and cost are and will be certanly the key issues. High seed quality can only be obtained by a thorough control of the entire seed production process, step by step from planning to final delivery. That requires science, technology, expertise, experience, good management and certanly, the most important, an absolute and unconditional commitment with quality. Seed testing for quality assurance is one important step in the process of production of high quality seed. In the late years a considerable amount of research has been published, particularly on the use of some Polymerase Chain Reaction DNA based new technologies (RAPD, microsatelites, AFLP) for genetic purity determinations in seed testing. As far as we know, no Brazilian seed company is using, on regular basis, RAPD or other molecular marker techniques in the determination of genetic purity in seed testing. Most of these are using morphological or physiological traits expressed by seed, seedling or mature plant and/or electrophoresis of seed or seedling proteins/isoenzymes for that purpose. Main reasons for that are: DNA molecular marker techniques are relatively new; lack of specialized personnel to run DNA molecular marker assays on routine basis; higher cost/sample when compared to proteins/isoenzymes electrophoresis.

O presente estudo visa fornecer subsídios para o processo de tomada de decisão de controle das plantas daninhas baseado em nível de dano na produtividade de culturas agrícolas. Com o objetivo de avaliar o aproveitamento de parâmetros das plantas e daninhas e das plantas de soja no monitoramento da interferência das plantas daninhas, foi realizado, em Botucatu (SP), um experimento sob condições de campo, com delineamento em blocos casualizados. A cultura foi mantida na presença ou ausência da comunidade vegetal infestante por diferentes períodos . O monitoramento da interferência das plantas daninhas na cultura da soja pode se dar através do acúmulo total de matéria seca da comunidade vegetal infestante e dos seguintes parâmetros de crescimento das plantas de soja: número de folhas trifolioladas, área da lâmina foliar, acúmulo de matéria seca de folhas e total. O acúmulo de matéria seca de cada espécie de planta daninha isoladamente, não foi parâmetros eficiente para determinar-se interferência (competição) na cultura da soja.

This research aims to subsidize decision making for weed control based on crop yield threshold. Field experiment was conducted in Botucatu (São Paulo, Brazil), with the objective of evaluating the utilization of soybean and weed parameters for monitoring weed interference on soybean yield. The experiment was delineated in a randomized block design. The crop was kept weedy or weed-free for different periods. Total weed dry matter and soybean parameters, such as number of leaves, leaf area, leaf dry matter and total dry matter, can be used for monitoring weed interference on soybean yield. Dry matter of each species separately, had no importance as a competitive element.