ABSTRACT The coffee sector is estimated to have a retail market value in excess of USD 83 billion, and over 125 million jobs have been created in the global coffee chain. The coffee specialty market has recently increased significantly, generating opportunities to certify coffee beans produced by sustainable practices. This avoids practices potentially harmful to the environment. Agroforestry, organic farming, intercropping, and soil conservation strategies are examples of sustainable alternatives in the production of coffee. In this review, we focus on practices for the sustainable management of coffee plantations that can help farmers fight problems caused by global warming. More specifically, we address soil organic matter and microbiota, the use of Urochloa grass as intercrop in coffee plantations, shading systems (including agroforestry), and organic coffee production. We concluded that from the agronomic viewpoint, we already have production techniques that can replace traditional ones with significant advantages accruing to the quality of coffee orchard ecosystems. Nevertheless, we need scientific research efforts to deal with the existing gaps and the engagement of the whole coffee chain as a means of guaranteeing an adequate profit to those smallholders who adopt and maintain sustainable practice and are capable of bringing several positive changes to the coffee crop, including the use of microbia-based commercial products and new organic sources of nutrients to complement chemical fertilizers and improve coffee quality.

Abstract Nitrogen uptake is essential for coffee growth and development, resulting in important effects on the biomass and final crop yield. Thus, like most nutrients, nitrogen is absorbed by the roots using water as a mean of transport, so that water stress and nitrogen can directly and indirectly affect various physiological processes. The aim of this paper was to evaluate the nitrogen metabolism in young plants of four varieties of coffee trees (Coffea arabica L.) submitted to water deficit (WD) and nitrogen supply. We have done a triple factorial (2 x 4 x 4) experiment entirely randomized. The plots received combinations of high or low N doses (7mmol/L and 2.8 mmol/L NO3 -), four water potentials (0; -0.4; -0.8; and -1.6 Mpa), and four varieties (Mundo Novo IAC379-19, Acauã F6 ofIBC - PR 82010, Catuaí Vermelho IAC 44, and Catuaí Amarelo IAC 62). One hundred and forty days after the I of the experiment (140 days after the beginning of N stress and 82 days after the beginning of WD stress) the activity of the enzymes nitrate reductase (NR) and glutamine synthetase (GS), concentration of nitrate, free proline, amino acids (TAA), and total proteins were determined in samples of leaf and root tissues. There were differences between varieties independently of WD and N dose for leaf NR, being ‘Acauã’ the cultivar that presented the highest and ‘Catuaí Vermelho’ the lowest value to this trait. The WD promoted an increase on the proline concentration in the roots. With low N dose, the activity of GS presented linear increases in response to WD. It was concluded that in young coffee plants under WD, proline can be involved in the osmotic adjustment, having its synthesis in the roots increased. Under WD, plants with good nitrogen nutrition presented larger leaf concentration of soluble amino acids and total soluble proteins. The varieties studied do not present differentiated responses to WD.

ABSTRACT Iodine is essential to human metabolism, being fundamental in the production of the thyroid hormones. The consumption of biofortified foods can contribute to the increase of its intake. The objective of this study was to increase the iodine concentration in lettuce, also evaluating its effects on plant growth and production. The experiment was conducted in a greenhouse, in a hydroponic system of aerated static solution. A completely randomized design was used, in a 2 x 5 factorial scheme (variety x iodine dose), with three repetitions. Two lettuce varieties were used, the iceberg lettuce and the crispy leaf lettuce, submitted to five doses of iodine (0, 10, 20, 30 and 40 µmol L-1), having as source potassium iodide. At 40 days after transplantation, both cultivars were collected and evaluated for the weight of fresh and dry matter, iodine content and levels in the leaves and the root volume. With increased doses, the plants showed symptoms of phytotoxicity, resulting in lower productivity. However, all doses promoted elevations in the total iodine levels of plants. Therefore, it is possible to increase the iodine content in lettuce leaves, being necessary to adjust the doses to be used.

ABSTRACT In tomato, foliar application of calcium-based nutrient solutions is used to complement soil fertilization. However, knowledge regarding the factors that influence the effectiveness of foliar fertilizer applications remains incomplete. The objective of this study was to evaluate the efficiency foliar fertilization with calcium for improving production and quality of hydroponic Sweet Grape tomatoes. An experiment was conducted in a commercial hydroponic system in a split-plit-plot scheme, with two calcium doses: 1,5 and 3 mmol L-1 of Ca. The solutions were sprayed on the leaves at intervals of 7 and 14 days, using commercial foliar fertilizers containing 0.3 g L-1 of calcium chloride or calcium acetate. The results indicate that the foliar application of calcium fertilizers, regardless of the amount of calcium provided in the nutrient solution and the frequency of applications, positively affects fruit production and quality. No difference was found between the effects of application of the two calcium sources, as well as the frequency of application.

RESUMO: A análise química de flores tem sido estudada em algumas culturas. Para o cafeeiro, a análise do tecido floral possibilitaria a antecipação do diagnóstico nutricional das lavouras. O estudo objetivou (i) comparar a composição mineral de flores e de folhas de cafeeiros (ii) e gerar normas para diagnose nutricional do cafeeiro com base na análise de tecidos de flores e folhas das plantas. Para isso, foram avaliados os teores de nutrientes em flores e folhas e a produtividade de café em 26 lavouras comerciais na região de Manhuaçu, MG, durante três anos. As faixas críticas de nutrientes determinadas em flores são: 2,78 - 3,17; 0,23 - 0,28; 2,80 - 3,12; 0,30 - 0,37; 0,24 - 0,30; 0,15 - 0,18 dag kg-1 de N, P, K, Ca, Mg e S, e 17 - 21; 12 - 18; 52 - 80; 26 - 43 e 28 - 48 mg kg-1 para Zn, Cu, Mn, Fe e B, respectivamente. As faixas críticas de nutrientes em folhas foram: 2,63 - 2,86; 0,13 - 0,14; 2,13 - 2,33; 1,04 - 1,22; 0,27 - 0,33; 0,15 - 0,18 dag kg-1 de N, P, K, Ca, Mg e S, e 9 - 14; 15 - 23; 80 - 115; 99 - 148 e 31 - 37 mg kg-1 para Zn, Cu, Mn, Fe e B, respectivamente. A diagnose nutricional do cafeeiro, quanto aos nutrientes N, P, Ca, Fe, Cu e Mn, pode ser antecipada por meio da análise de flores.

ABSTRACT: The chemical analysis of flowers has been studied for some crops. In coffee trees, the flower tissue analysis could anticipate the nutritional diagnosis. This study aimed to: (i) compare the mineral composition of coffee flowers and leaves; and to (ii) generate reference values for nutritional diagnosis of coffee trees, based on flower and leaf analysis. Nutrient content of flowers and leaves and coffee productivity were evaluated in 26 commercial farms located in Manhuaçu, MG, Brazil throughout three years. The critical nutrient content range in flowers are respectively: 2.78 - 3.17, 0.23 - 0.28, 2.80 - 3.12, 0.30 - 0.37, 0.24 - 0.30, 0.15 - 0.18 dag kg-1 of N, P, K, Ca, Mg, and S; and 17 - 21, 12 - 18, 52 - 80, 26 - 43, and 28 - 48 mg kg-1 of Zn, Cu, Mn, Fe, and B. For leaves, the critical nutrient ranges are respectively: 2.63 - 2.86, 0.13 - 0.14, 2.13 - 2.33, 1.04 - 1.22, 0.27 - 0.33, 0.15 - 0.18 dag kg-1 of N, P, K, Ca, Mg, and S; and 9 - 14, 15 - 23, 80 - 115, 99 - 148, and 31 - 37 mg kg-1 of Zn, Cu, Mn, Fe, and B. The nutritional diagnosis of coffee trees for N, P, Ca, Fe, Cu, and Mn can be anticipated using flower analysis.

ABSTRACT The adoption of more productive and nutrient-demanding genotypes, in addition soils with low availability of nutrients of soils under forest plantations, lead high fertilizer demand and justify research that seeks to rationalize the use of these inputs. Therefore, we aimed with this research to determine classes of interpretation of soil fertility using boundary line (BL) and estimate macronutrient sufficiency ranges for eucalyptus. Fertility classes and sufficiency ranges were obtained using a database of areas cultivated with eucalyptus in the Central-East region of Minas Gerais, Brazil, totaling 689 plots, containing information on yield, leaf contents, and soil chemical properties. Scatter plots were drawn relating the mean annual increment (MAI) in trunk volume (relative) with soil organic matter (OM), phosphorus (P), potassium (K+), calcium (Ca2+), and magnesium (Mg2+) of the 0.00-0.20 m layer. Those graphs and equations were used to estimate soil fertility classes. Leaf contents of N, P, K, Ca, and Mg were plotted with soil contents of OM, P, K+, Ca2+, and Mg2+. Using the Quadrant Diagram of the plant-soil Relationship (QDpsR) method, horizontal and vertical lines were drawn separating the cloud of points in four quadrants. With the points at the quadrants III and I, regression equations were fitted. To obtain foliar sufficiency ranges, soil values of critical and optimal levels of OM, P, K+, Ca2+, and Mg2+, obtained by BL, were substituted in the equations generated by the QDpsR method. The appropriate soil content ranges determined by BL for productivity of 47.7 m3 ha-1 yr-1 were: 24.75-38.28 g kg-1 of OM, 8.5-14.6 mg dm-3 of P, 100.0-150.35 mg dm-3 of K+, 0.77-1.47 cmolc dm-3 of Ca2+, and 0.25-0.43 cmolc dm-3 of Mg2+. Leaf content ranges determined by QDpsR are: 19.4-21.3 g kg-1 of N, 1.0-1.2 g kg-1 of P, 8.5-10.6 g kg-1 of K, 4.8-6.1 g kg-1 of Ca, and 1.9-2.4 g kg-1 of Mg. The critical levels of nutrients in the soil, obtained by the BL method, and the leaf sufficiency ranges, obtained using the QDpsR method, are similar to those existing in the literature. This indicates that this methodology is reliable in establishing standards and that the critical levels obtained can be used to improve the recommendation of fertilizers for eucalyptus.

Abstract Studies evaluating the influence of nutrients on plant anatomy are very important because nutritional deficiencies can alter the thickness and shape of certain tissues, compromising their functionality what can explain the reduction of productivity. The aim of this study was to characterize the anatomical changes in cherry tomato plants subjected to calcium (Ca) and magnesium (Mg) deficiencies. The experiment was conducted in nutrient solution and the plants subjected to three treatments: complete solution (Control), Ca restriction (1 mmol L-1 of Ca) and Mg omission (without Mg). The experimental design was completely randomized, with three repetitions. Sixty days after seedling transplanting leaves and stem were collected and submitted to anatomical evaluations. Ca or Mg deficiency promotes most evident anatomical changes in chlorophyllous and vascular tissues of the leaves, rather than in the stems. Leaves of ‘Sindy’ tomato plants with a concentration of 1.7 g kg-1 of Mg and visual symptoms of Mg deficiency present hyperplasia of both tissues, phloem and xylem. This deficiency also promotes increases in the thickness of mesophyll, spongy parenchyma and palisade parenchyma, and consequently of leaf thickness. The midrib of the leaves with a concentration of 10 g kg-1 of Ca, without visual symptoms of deficiency presented phloem hypertrophy and hyperplasia.

RESUMO A obtenção de frutos de boa qualidade e com alta produtividade é um dos principais desafios da cultura do tomateiro. Com o adensamento de cultivo, há redução na massa fresca de frutos e aumento na produtividade por área; porém, a comercialização considera o número e a massa fresca de frutos. Objetivou-se avaliar a produtividade e a qualidade de frutos de tomateiro híbrido de crescimento indeterminado (Rebeca), cultivado em sistema hidropônico, com diferentes densidades de plantio e número de cachos por planta. O experimento foi conduzido em casa-de-vegetação, em sistema de subirrigação contendo argila expandida como substrato. O delineamento foi em blocos ao acaso, com parcelas subdivididas e três repetições. Nas parcelas, foram alocadas quatro densidades de plantio (11,1 plantas m-2; 8,3 plantas m-2; 6,6 plantas m-2; e 5,5 plantas m-2) e, nas subparcelas, o número de cachos por planta (um ou dois). A produtividade total foi influenciada pela interação densidade de plantio x número de cachos por planta. O tratamento que possibilitou maior produção foi o de 11,1 plantas m-2 com dois cachos, com 22,61 kg m-2 ou 226,1 t ha-1, em um ciclo de cultivo de 134 dias. As variações observadas para os teores de nutrientes minerais nas folhas e frutos do tomateiro com um ou dois cachos, em densidades de 5,5-11,1 plantas m-2, não comprometem a qualidade dos frutos e nem influenciam na produção de frutos comercializáveis, no cultivo hidropônico.

ABSTRACT Obtaining a high yield of good quality fruits is one of the main challenges of the tomato crop. The enhancement in plant density promotes a reduction in the fruit fresh mass and an increase the yield per area. On the other hand, commercialization parameters take into account number and fresh mass of fruits. This study aimed at evaluating the yield and fruit quality of indeterminate growth hybrid tomato (Rebeca), cultivated in a hydroponic system, with different planting densities and number of bunches per plant. The experiment was conducted under greenhouse conditions, in a sub-irrigation system containing expanded clay as substrate. A split-plot randomized block design, with three replications, was used. In the plots, four planting densities (11.1 plants m-2, 8.3 plants m-2, 6.6 plants m-2 and 5.5 plants m-2) were allocated and, in the subplots, the number of bunches per plant (one or two). The total yield was influenced by the interaction planting density x number of bunches per plant. The treatment that allowed the highest yield was 11.1 plants m-2 with two bunches, with 22.61 kg m-2 or 226.1 t ha-1, in a crop cycle of 134 days. The observed variations for the nutrient contents of leaves and fruits of tomato plants with one or two bunches, at densities of 5.5-11.1 plants m-2, do not compromise the fruit quality nor influence the production of tradable fruits, using the hydroponic system.

Resumo: O objetivo deste trabalho foi avaliar o efeito do cobre na composição química dos grãos de café e na qualidade da bebida, bem como relacionar ambas aos teores foliares de Cu do cafeeiro (Coffea arabica). Cultivaram-se cafeeiros em sistema hidropônico com 0,2, 0,4, 0,8, 1,6 e 3,2 μmol L-1 de Cu até a produção de frutos. Avaliou-se a produção do café, e, após secagem dos grãos maduros, determinaram-se: a concentração foliar de cobre; a acidez total titulável; o índice de coloração; a condutividade elétrica; o K lixiviado; a atividade da polifenoloxidase (PPO); as concentrações de cafeína, trigonelina, ácidos orgânicos, fenóis totais, ácidos clorogênicos (3-CQA, 4-CQA e 5CQA), sacarose, glicose, arabinose, manose e galactose; e a qualidade sensorial dos grãos torrados. O Cu aumentou a produção de grãos, a atividade de PPO e as concentrações de ácidos orgânicos, 3-CQA, sacarose e arabinose. A acidez total titulável, os fenóis totais e o 4-CQA e o 5-CQA foram reduzidos com o incremento das doses de Cu. Os teores foliares relacionados aos valores máximos e mínimos dos atributos de qualidade desejáveis e indesejáveis variaram de 5,6 a 11,4 mg kg -1 de Cu, respectivamente. O cobre afeta a produção e a composição química dos grãos de café, e os atributos relacionados à qualidade são maximizados com baixas concentrações foliares do nutriente.

Abstract: The objective of this work was to evaluate the effect of copper on the chemical composition of coffee beans and on the quality of the beverage, relating both of them to the Cu leaf contents in coffee (Coffea arabica) plants. Coffee plants were grown in a hydroponic system containing 0.2, 0.4, 0.8, 1.6, and 3.2 μmol L-1 Cu until fruit setting. Coffee bean production was evaluated, and, after the cherries were dried, the following characteristics were determined: leaf Cu content; total titratable acidity; color index; electrical conductivity; leached K; polyphenol oxidase (PPO) activity; concentrations of caffeine, trigonelline, organic acids, total phenols, chlorogenic acids (3-CQA, 4-CQA, and 5-CQA), sucrose, glucose, arabinose, mannose, and galactose; and sensory quality of roasted beans. Cu increased bean yield, PPO activity, and the concentrations of organic acids, 3-CQA, sucrose, and arabinose. Total titratable acidity, total phenols, 4-CQA, and 5-CQA were reduced with increasing Cu doses. Leaf contents related to the maximum and minimum values of desirable and undesirable quality attributes ranged from 5.6 to 11.4 mg kg-1 Cu, respectively. Copper affects the production and chemical composition of coffee beans, and the attributes related to quality are maximized in plants with low leaf contents of the nutrient.

ABSTRACT: Research focused on adequate nutrition of plants is essential in modern coffee production to increase yield and develop more efficient management strategies with greater environmental and economic sustainability. The objectives of this study were to establish critical and optimal levels of soil fertility properties for high yielding Arabica coffee crops using the Boundary Line method and, then, relate the macronutrient contents in the diagnostic leaf of coffee to the macronutrients available in the soil using the Quadrant Diagram of the Plant-Soil Relationship (QDpsR). The study made use of a soil chemical analysis database, leaf macronutrient contents, and Arabica coffee yield from five representative coffee-growing regions in Minas Gerais. An analysis of data consistency was performed, and relative fruit yield (RFY) was related to the soil organic matter (SOM), P, K, Ca, and Mg contents in the soil, establishing the boundary line (BL) in each graph. Equations were adjusted from the BL points, and the equation that best fit was selected. Using the QDpsR method, the response plane was divided into four quadrants, where the total leaf contents of N, P, K, Ca, Mg, and S were plotted as a function of the contents of SOM, P, K, Ca, and Mg in the soil, on the y and x axes of the Cartesian coordinate system. The regression equations were adjusted to the pairs of points (y, x) of quadrants III and I and were used to estimate the macronutrient sufficiency ranges from the critical and optimal levels in the soil. The BL method was used to determine the class of good soil fertility for SOM, P, K, Ca, and Mg. The QDpsR method allows determination of response curves for leaf content as a variable of soil contents, making it possible to estimate the sufficiency ranges in the diagnostic leaf of coffee: 33.4-35.8 g kg-1 of N, 1.4-1.6 g kg-1 of P, 24.4-27.0 g kg-1 of K, 11.9-13.6 g kg-1 of Ca, 3.8-4.5 g kg-1 of Mg, and 1.4-1.8 g kg-1 of S; which were consistent with the sufficiency ranges considered suitable for the crop. This study demonstrated the importance of leaf analysis as a tool for evaluation of the nutritional status of Arabica coffee since the technique is consistent with the theoretical principles underlying it.

Abstract Coffee tree is a shrub with dimorphic branches. The orthotropic stem grows vertically with two near-horizontal plagiotropic branches, per node, in opposite phyllotaxy. The consecutive nodes of the orthotropic stem are organized in parastichies. We report here mutant plants of Coffea arabica with triple plagiotropic branch, resulted from the whorled phyllotaxy of the orthotropic stem. In mutant plants three plagiotropic branches in the same node are separated by angles of approximately 120o, while in normal plants two plagiotropic branches in the same node are separated by angles of approximately 180o. In mutant plants the angles of the parastichies increase approximately 50o clockwise between consecutive nodes, while in normal plants the angles increase approximately 87o. The plant architecture is changed. The triple plagiotropic branch is a putative mutant with potential to be explored in coffee breeding programs. The hypotheses for the origin of the mutation and the research perspectives are discussed.

RESUMO A macaúba [Acrocomia aculeata (Jacq.) Lood. ex Mart] vem sendo domesticada para subsidiar programas de produção de biodiesel no Brasil. Contudo, pouco se sabe sobre a produção de mudas desta espécie. Objetivou-se avaliar misturas de substratos, doses de calcário e de fósforo na correção do substrato e a frequência de adubação de cobertura em mudas de macaúba. Foram instalados três ensaios conduzidos em casa de vegetação, até o sexto mês de cultivo na fase de viveiro. Ensaio 1: avaliação de percentuais das frações orgânica e mineral totalizando sete misturas de substratos. Ensaio 2: avaliação de quatro doses de correção do solo com calcário versus quatro doses de fosfatagem. Ensaio 3: avaliação da frequência de fertilização com N, K e Mg em cobertura. Nos três ensaios foram observadas diferenças significativas para maioria das variáveis analisadas (altura de plantas, número de folhas, massa seca da parte aérea, massa seca da raiz, vigor e diâmetro do bulbo). Como resultados principais têm-se: Ensaio 1 - o melhor desenvolvimento das mudas é observado em substratos com pelo menos 25% de material orgânico. Ensaio 2 - doses variando de 0,50 a 1,25 kg de calcário associada à fosfatagem com 3,00 a 4,00 kg de superfosfato simples por m3 de substrato proporciona melhor desenvolvimento das mudas. Ensaio 3 - a adubação de cobertura proporciona melhor desenvolvimento das mudas independentemente da frequência.

ABSTRACT The macaw palm [Acrocomia aculeata (Jacq.) Lood. ex Mart] has been domesticated to subsidize biodiesel production programs in Brazil. However, little is known about the seedling production of this species. This study aimed to evaluate substrate mixtures, limestone and phosphorus rates for substrate amendment and topdressing frequency in macaw palm seedlings. Three trials were conducted in a greenhouse up to six months of nursery cultivation. Trial 1: determination of percent mineral and organic fractions of seven substrate mixtures. Trial 2: evaluation of four limerates for soil amendment versus four phosphorus rates. Trial 3: evaluation of N, K and Mg topdressing frequency. Significant differences were found in the three trials for most of the variables (plant height, leaf number, shoot dry mass, root dry mass, vigor and bulb diameter). The main results obtained were as follow: Trial1 - the best seedling growth was observed in substrates with at least 25% organic matter. Trial2 -lime rates ranging from 0.50 to 1.25 kg associated with 3 to 4 kg of single superphosphate per m3 of substrate provided the best seedling growth. Trial 3 - topdressing fertilization provided better development of seedlings regardless of frequency.

RESUMO A exploração econômica da macaúba [Acrocomia aculeata (Jacq.) Lodd. ex Mart.] está passando por processo de transição do extrativismo para cultivos agronômicos, o que requer estudos com adubação para a cultura. Objetivaram-se avaliar a resposta de três acessos de macaúba a doses crescentes de nitrogênio e potássio, cultivados até o segundo ano no campo; e obter um referencial para os teores de nutrientes minerais na folha. O experimento foi montado em parcelas subdivididas, no delineamento em blocos casualizados, com cinco tratamentos principais nas parcelas (doses de N e K) e três tratamentos secundários nas subparcelas (acessos), com três repetições, cada parcela contendo três plantas. Ao final do segundo ano de cultivo, foram avaliados: altura de plantas, número de folhas, vigor e teores de nutrientes minerais nos tecidos foliares. Observou-se resposta diferenciada entre os acessos avaliados, indicando que existem genótipos mais eficientes no uso dos insumos minerais. Houve resposta diferenciada e positiva a doses crescentes de adubação com N e K em cobertura no desenvolvimento vegetativo de acessos de macaúba até o segundo ano de cultivo no campo, indicando que há variabilidade na espécie quanto à eficiência nutricional. A dose de fertilização com N e K correspondente a 360 g de N + 480 g de K2O por planta, aplicada em quatro parcelamentos durante os dois anos iniciais do cultivo, foi insuficiente para alcançar o desenvolvimento vegetativo máximo dos três acessos de macaúba avaliados. Não houve variação nos teores de macro e micronutrientes na matéria seca das folhas de macaúba dos três acessos avaliados.

ABSTRACT The economic exploitation of macaw palm [Acrocomia aculeate(Jacq.) Lodd. ex Mart.] is currently in transition, from extractivism to agricultural cultivation, thus requiring studies on the fertilization of the crop. This study evaluated the response of three genotypes of macaw palm to increasing rates of nitrogen and potassium, grown in the field until the 2nd year and to establish reference contents of mineral nutrients in the leaf. The experiment was a split-plot randomized block design with five main treatments (N and K rates) and three secondary treatments (genotypes), with three replications, each plot containing three plants. Plant height, leaf number, vigor, and nutrient contents in leaf tissues were evaluated at the end of 2nd year of cultivation. Differential responses were observed among genotypes, indicating that some genotypes are more efficient in the use of mineral inputs. There was a differentiated and positive response to increasing side-dressed N and K rates in the vegetative development of macaw genotypes until the 2nd year of field cultivation, indicating variability in the species in terms of nutrient use efficiency. The N and K fertilization rate corresponding to 360 g N + 480 g K2O per plant, in four split applications over the two years of cultivation, was insufficient to induce maximum vegetative development in the three macaw genotypes. There was no variation in macro- and micronutrient contents in leaf dry matter of the three macaw genotypes.

A razão entre nitrogênio (N) e potássio (K) pode ser importante para obtenção de cafés especiais, uma vez que doses adequadas destes nutrientes podem suprimir ou aumentar a concentração de certos compostos químicos essenciais ao sabor e aroma da bebida. Objetivou-se com este trabalho avaliar o efeito de diferentes relações N:K e doses de K na qualidade da bebida do café. Foram realizadas avaliações referentes à concentração de compostos químicos essenciais à formação de sabor e aroma dos grãos e teores de N, K e cafeína em folhas e grãos. A relação N:K e o K são importantes definidores da qualidade da bebida de café sendo a melhor qualidade observada na relação N:K 1:1.56. Os grãos que apresentam melhor qualidade da bebida têm maiores atividade da PPO, cafeína, índice de coloração, açúcares redutores e menores acidez total titulável, pH, condutividade elétrica e lixiviação de potássio.

The ratio of nitrogen (N) to potassium (K) is important in the production of specialty coffees because the relative amounts of N and K can either suppress the formation or increase the concentration of compounds that are essential to the flavor and aroma of specialty coffees. The purpose of this study was to evaluate the effect of different N:K ratios (w/w) and K doses on the cup quality of coffee. The concentrations of chemical compounds essentials to achieve good flavor and aroma, the N and K contents, and the caffeine contents of coffee leaves and beans were evaluated in this study. The N:K ratio and the K dose were found to be important factors in cup quality, the best quality corresponding to an N:K ratio of 1:1.56. The best cup quality was obtained from beans with greater PPO activity, caffeine, color index, and sugars and lower total tritatable acidity, pH, electrical conductivity and leached potassium.

A propagação vegetativa de plantas ornamentais pode ser acelerada por meio da aplicação de reguladores de crescimento. Dentre eles, vêm-se destacando o uso de auxinas, hormônios vegetais com efeitos fisiológicos no alongamento celular e no enraizamento adventício. Alternativamente, a aplicação de ácidos húmicos, fração bioativa da matéria orgânica do solo, também resulta em incrementos na formação de raízes de estacas de plantas ornamentais. O objetivo deste trabalho foi estudar as características de crescimento e os teores nutricionais das plantas de cróton e hibisco, durante a aclimatação das mudas, em resposta a diferentes concentrações de ácido indolbutírico (AIB) e de ácido húmico (AH), aplicados para o enraizamento adventício das estacas. O experimento foi conduzido em viveiro, sendo as estacas caulinares apicais tratadas com soluções de concentrações iguais a 0, 250, 500, 1000 e 2000 mg L-1 de AIB e de 0, 10, 20, 30 e 40 mg L-1 de C de AH. Aos 45 dias de enraizamento das estacas no substrato casca de arroz carbonizado, elas foram transferidas individualmente para sacolas de plástico preto de 2,0 dm3, contendo, como substrato, uma mistura de solo: areia: esterco (2:1:1). Aos 90 dias de aclimatação, as plantas foram coletadas para mensuração das variáveis de crescimento e nutricionais. Os resultados permitiram concluir que a aplicação de AIB estimula a absorção de nutrientes e o crescimento das estacas de cróton e de hibisco transplantadas, contribuindo para formação de mudas vigorosas. Resposta semelhante aconteceu com a aplicação de AH apenas em estacas de hibisco.

The vegetative propagation of ornamental plants can be accelerated by applying plant growth regulators. Amongst them, the use of auxins, plant hormones with physiological effects on cell elongation and rooting have stood out. Alternatively, the application of humic acids, bioactive fraction of soil organic matter, also results in increases in rooting cuttings of ornamental plants. The objective of this work was to study the growth characteristics and the nutritional contents of croton and hibiscus plants during acclimation of seedlings in response to different concentrations of indolebutyric acid (IBA) and humic acid (HA) applied to cuttings for rooting. The experiment was conducted in greenhouse, and the apical stem cuttings were treated with solutions with concentrations of 0, 250, 500, 1000 and 2000 mg L-1of IBA and 0, 10, 20, 30 and 40 mg L-1 of C from HA. At 45 days of rooting in carbonized rice husk, they were individually transferred to plastic bags of 2.0 dm3 containing a mixture of soil: sand: manure (2: 1: 1) as substrate. At 90 days of acclimation, the plants were collected for measurement of growth and nutritional variables. The results showed that the application of the IBA stimulates the absorption of nutrients and growth of croton cuttings and transplanted hibiscus, contributing to formation of vigorous seedlings. A similar response occurred with the application of HA in hibiscus cuttings