Abstract Objective: To evaluate the efficacy of desensitizing agents for the obliteration of dentinal tubules subjected or not to a simulated oral environment. Material and Methods: Dentinal discs (n=8) treated with Riva-Star (RS) or PRG-Barrier-Coat (PRG) were submitted (cycled) or not submitted (control) to erosive-abrasive-thermal cycles and evaluated using scanning electron microscopy/energy dispersive spectroscopic analysis. The variables analyzed were tubule obliteration and dentin surface chemical composition. Data were analyzed by non-parametric tests (p<0.05). Results: The cycled and control groups did not differ significantly for the responses in each material. The PRG control and cycled groups had fewer visible tubules and a higher proportion of totally obliterated tubules than the RS groups. The percentages of silver coverage were higher in the RS-control than in the RS-cycled. There was a significant inverse correlation between the presence of silver and non-obliterated tubules (R=-0.791; p<0.001). The percentages of carbon, aluminum, strontium, and potassium were significantly higher in the PRG-control and PRG-cycled compared to the RS control. The percentages of calcium, phosphorus, and silver were significantly higher in the RS compared to the PRG groups. PRG-control showed a higher percentage of boron than RS-control. Conclusion: PRG promoted greater tubule obliteration than SR. Simulated stress did not affect the obliterating effect of each agent. Greater silver coverage corresponded to a lower proportion of non-obliterated tubules in RS. Carbon, aluminum, strontium, boron, and potassium predominated in the dentin surface treated with PRG, while calcium, phosphorus, and silver prevailed in RS groups.

RESUMO A modificação do manejo hídrico na cultura do café Conilon (Coffea canephora) pode ser uma estratégia para melhorar a eficiência do manejo nutricional e garantir um melhor aproveitamento por parte dos genótipos para região de altitude de transição. O objetivo do estudo foi avaliar as características nutricionais de 27 genótipos de C. canephora, submetidos a dois manejos de água no solo, visando identificar genótipos que apresentam evidências de maiores teores foliares, exportações e potencial de reciclagem de nutrientes em seus ramos produtivos. O experimento foi conduzido em esquema de parcelas subdividida, em delineamento de blocos casualizados, com três repetições. Os tratamentos consistiram nos 27 genótipos de C. canephora e dois manejos de água no solo (“Irrigado” e “Suprido apenas pela chuva”). Foram avaliados os teores nutricionais foliares, os conteúdos nutricionais exportados pelos frutos e os conteúdos nutricionais potencialmente recicláveis após a poda (folhas e caule dos ramos plagiotrópicos), dos macronutrientes: nitrogênio, fósforo, potássio, cálcio e magnésio. Houve diferenciação entre os genótipos para todas as características avaliadas em ambos os manejos de água no solo. Porém, houve formação de um maior número de grupos homogêneos entre os genótipos no manejo irrigado. Os genótipos apresentaram distinção nas características nutricionais em resposta aos manejos de água no solo. Os genótipos 108 e 302 acumularam maiores conteúdos nutricionais exportado pelos frutos, independentemente do manejo de água no solo.

ABSTRACT The modification of water management in the Conilon coffee (Coffea canephora) crop is a possible strategy to improve nutritional management efficiency and ensure better use of the genotypes for regions of transitional altitude. The objective of this study was to evaluate the nutritional characteristics of 27 genotypes of C. canephora and submit them to two water management schemes in soil. The goal was to find evidence of higher leaf contents, exports, and nutrient recycling potential in the productive branches of various genotypes. The experiment was carried out in a randomized block design with three replications in a split-plot scheme. The treatment consisted of 27 genotypes of C. canephora and two water management schemes in soil (“Irrigated” and “Rainfed”). Nutritional content in leaves, exported by fruits, and pruned (leaves and stem of plagiotropic branches) recyclable contents were evaluated for nitrogen, phosphorus, potassium, calcium, and magnesium. Variations were observed among genotypes for all the parameters evaluated in both water management in soil. However, significant homogeneous groups were formed among the genotypes in the irrigated management. Furthermore, the genotypes showed distinct nutritional characteristics in response to water management in the soil. Genotypes 108 and 302 had higher nutritional content and were exported by fruits, regardless of soil water management.

ABSTRACT Due to the possibility of enhancing the physiological responses by modulating the architecture of coffee trees, the objective of the study was to analyze the leaf gas exchanges and biomass allocation of Arabica coffee cultivated with different numbers of orthotropic stems. The experiment was carried out in a plantation located in Santa Teresa-ES, Brazil, cultivated with spacing of 2.5×1.0 m, using the cultivar Catuaí Vermelho IAC44. The gas exchange rates were monitored along stages of the phenological cycle (2014/2015), following a split-plot scheme, 3×3 (number of orthotropic stems per plant in three levels: 1, 2 and 3; and the phenological stages in three levels: flowering, fruit formation and maturation). The allocation of biomass in the plagiotropic branches was also analyzed during the phenological stage of fruit maturation. The management of the number of orthotropic stems affected the photosynthetic responses and biomass allocation of coffee trees. Under the studied conditions, cultivating the plants with two orthotropic stems created conditions which promoted the photosynthetic responses. Keeping more stems promotes the availability of leaves per amount of produced fruits in the plagiotropic branches, allowing the plant to sustain the production with less metabolic wearing.

RESUMO O estudo do comportamento do cafeeiro arábica conduzido com mais de um ramo ortotrópico surge como fonte de alternativas de melhoria da arquitetura da copa e da produção da lavoura cafeeira. Por isso, objetivou-se, com este trabalho, analisar a arquitetura da copa do cafeeiro arábica conduzido com diferentes números de ramos ortotrópicos por planta. Um experimento foi realizado em campo, no município de Santa Teresa, ES, em altitude de 740 m, topografia ondulado-acidentada, com precipitação e temperatura média anual de 1.282 mm e 21,1 ºC, respectivamente. O espaçamento foi de 2,5 x 1,0 m e o cultivar foi o Catuaí Vermelho IAC44. Em novembro de 2012, aos oito anos de idade, a lavoura foi recepada e as brotações que surgiram foram conduzidas para promover o estabelecimento de três tratamentos referentes ao número de ramos ortotrópicos: um, dois ou três ramos por planta. O experimento seguiu delineamento em blocos casualizados, com oito blocos e os três tratamentos. Plantas de cafeeiro arábica com dois ou três ramos ortotrópicos não se diferiram e apresentaram maior área e volume de copa, densidade de enfolhamento e área foliar dos ramos plagiotrópicos. A condução do cafeeiro arábica com dois ramos ortotrópicos por planta proporcionou maior produção de café beneficiado por hectare, bem como maior proporção de grãos graúdos (grãos maiores e com massa mais homogênea).

ABSTRACT The study of the behavior of Arabica coffee trees cultivated with more than one orthotropic branch appears as an alternative to improve the canopy architecture and may enhance the coffee crop yield. In this context, the objective of this study was to analyze traits of canopy architecture of Arabica coffee trees cultivated with different numbers of orthotropic branches per plant. For this end, an experiment was carried out in a productive field located in Santa Teresa-ES, at an altitude of 740 m, the place presents wavy-rugged topography, with annual rainfall and average air temperature of 1,282 mm and 21.1 ºC, respectively. The spacing between plants was 2.5 x 1.0 m and the cultivar used was Catuaí Vermelho IAC44. In November 2012, with the plants at eight years of age, the plants were pruned and the new emerged sprouts were conducted to promote the establishment of three treatments regarding the number of orthotropic branches: one, two or three branches per plant. The experiment followed a randomized block design, with eight repetitions and three treatments. The coffee plants grown with two or three orthotropic branches did not differ among themselves and presented larger canopies in area and volume, larger foliage density and leaf area of their plagiotropic branches. The conduction of the Arabica coffee trees with two orthotropic branches per plant promoted greater production of processed coffee per hectare, as well as greater proportion of large grains (resulting in larger grains and a more homogeneous mass).

RESUMO O crescente consumo de batata yacon tem despertado interesse mundial pela cultura, o que tem gerado demanda por elucidações científicas de diversos fatores associados ao seu manejo agrícola. Entre as demandas, estão os estudos realacionados aos efeitos efeitos do alumínio (Al3 +) sobre o desenvolvimento de plantas yacon. Assim, este estudo foi desenvolvido para avaliar os efeitos do alumínio sobre a brotação e o crescimento inicial de mudas de yacon. O experimento foi realizado em delineamento inteiramente casualizado, com três repetições e seis teores de de alumínio no substrato: 0, 10, 25, 50, 100 e 200 mg L-1. O comportamento das plântulas de yacon foi avaliado pelo tempo e índice de velocidade de emergência, número de folhas, altura, área foliar, comprimento da radícula e massa seca de folhas, hastes e radículas. A presença de alumínio no substrato influencia negativamente a emergência e o crescimento inicial da yacon, causando redução no desenvolvimento foliar (número de folhas e área foliar), no acúmulo de biomassa, crescimento e restringindo, especialmente, o desenvolvimento da radícula. A toxicidade do alumínio inibe completamente o crescimento radicular em concentrações acima de 83 mg L-1, nas condições controladas usadas neste experimento.

ABSTRACT The increasing consumption of yacon potato has raised worldwide interest in its crop and generated demand for scientific elucidations of several factors associated to its agricultural management. Among the demands, there are the studies related to the effects of aluminum (Al3+) on the development of yacon plants. Thus, this study was developed to evaluate the effects of aluminum on budding and initial growth of yacon plantlets. The experiment was carried out in a completely randomized block design, with three replications and six aluminum contents in the substrate: 0, 10, 25, 50, 100, and 200 mg L-1. The response of yacon plantlets to aluminum contents was evaluated by the emergence time, emergence speed index, number of leaves, plant height, leaf area, radicle length, and dry mass weight of leaves, stems, and radicles. The presence of aluminum in the substrate negatively influences the emergence and initial growth of yacon, causing losses in foliage development (number of leaves and leaf area), in biomass accumulation, growth and, especially, restricting the development of radicles. Aluminum toxicity fully inhibits radicle growth in substrate contents above 83 mg L-1, under the controlled conditions used in this experiment.

The study objective was to determinate the concentration of aluminum that allow to distinguish genotypes of Jatropha for tolerance to this element, using the solution-paper method. For this study, seeds of four genotypes of Jatropha, were germinated at different Al concentrations (0, 15, 40, 80 and 120 mg L-1). After 14 days, the root length was measured for all treatments. It was observed that there are different tolerance levels for the genotypes. The root length decreased exponentially with the increase of the Al concentration. The solution-paper method allows the selection of genotypes of Jatropha in relation to aluminum tolerance and the concentration of 40 mg L-1 of Al is recommended to discriminate the tolerance of genotypes to this element.

El objetivo de la investigación fue evaluar el efecto de la concentración del aluminio en solución que mejor diferencia la tolerancia al aluminio en genotipos de Jatropha, utilizando el método papel-solución. Semillas de cuatro genotipos diferentes de Jatropha (CNPAE-248, CNPAE-301,CNPAE-308 y CNPAE-144) fueron germinadas en diferentes concentraciones de Al (0, 15, 40, 80 y 120 mg L-1) usando la técnica de papel-solución. Después de 14 días se midió el tamaño de la raíz primaria en todos los tratamientos. Los resultados aquí presentados muestran que hay un comportamiento diferente de los genotipos para la tolerancia donde el tamaño de la raíz primaria de estos disminuye exponencialmente en relación con el aumento de los niveles de Al. El método de papel-solución permite la selección de los genotipos de Jatropha en relación con la tolerancia al aluminio; recomienda utilizar la concentración de 40 mg L-1 de Al para discriminar diferencias en la tolerancia a este elemento.

Apesar do controle químico da ferrugem do cafeeiro e a adubação nitrogenada serem amplamente pesquisado no Brasil, não existem trabalhos na literatura que apresentam esta interação em plantas de café conilon. Desta forma, objetivou-se estudar a interação entre o efeito da adubação nitrogenada e de ciproconazol+tiametoxam, no crescimento de mudas de café conilon, cultivar "Emcaper 8151 - Robusta Tropical", em ambiente controlado. Para isso, utilizou-se o delineamento experimental inteiramente casualizado, com quatro repetições, em esquema simples, com 13 níveis de combinações de nitrogênio e ciproconazol+tiametoxam. Os níveis de nitrogênio e ciproconazol+tiametoxam foram combinados seguindo modelo matricial Box Berard aumentada a 3(2k + 2k + 2k + 1). Os resultados mostram que as combinações do nível recomendado de ciproconazol+tiametoxam e de nitrogênio influenciaram negativamente as variáveis analisadas das plantas de café conilon, na condição de estudo.

Although the chemical control of coffee rust and the nitrogen fertilization are widely studied in Brazil, there are no documented studies that show this interaction in conilon coffee plants. Thus, the objective of this experiment was to study the interaction between the effects of nitrogen and cyproconazole+thiamethoxam in the growth of conilon coffee seedlings, cultivar "Emcaper 8151 - Robusta Tropical", in controlled environment. For this, a completely randomized design was used, with four replicates, simple layout, with 13 levels of combinations of nitrogen and cyproconazole+thiamethoxam. The levels of nitrogen levels and cyproconazole+thiamethoxam were combined following a Box Berard increased to 3 (2k + 2k + 2k + 1) matrix model. The results show that the combinations of the recommended level of cyproconazole+thiamethoxam and nitrogen influenced negatively the analyzed variables of the conilon coffee plants, in the studied conditions.

O estudo da eficiência nutricional de plantas enxertadas de cafeeiro é importante para a seleção de combinações enxerto/porta-enxerto, visando atingir melhor desenvolvimento e produção. Este trabalho teve como objetivo avaliar as diferenças na eficiência de absorção e utilização de B, Zn, Cu e Mn em mudas enxertadas de cafeeiro. O experimento foi conduzido em vasos de 20 litros contendo como substrato terra, areia e esterco na proporção de 3:1:1, onde as plantas permaneceram por um período de 18 meses. Utilizaram-se como enxerto quatro genótipos de Coffea arabica L.: os cultivares Catuaí-Vermelho IAC 15 ('Catuaí 15') e Oeiras MG 6851 ('Oeiras') e os híbridos H419-10-3-4-4 ('H419') e H514-5-5-3 ('H514') do programa de melhoramento da EPAMIG/UFV. Como porta-enxerto foram empregados cinco progênies de famílias de meio-irmãos de clones de Coffea canephora Pierre ex Froenher cv. Conilon: ES 21, ES 36, ES 26, ES 23 e ES 38 do programa de melhoramento de café robusta do Incaper. O delineamento experimental foi inteiramente casualizado, com 24 tratamentos e três repetições, sendo quatro pés-francos e 20 combinações de enxertia. A eficiência nutricional das plantas variou conforme a combinação enxerto/porta-enxerto. O cultivar Oeiras não foi beneficiado por nenhuma enxertia, apresentando redução da produção total de matéria seca em todas as combinações comparativamente ao respectivo pé-franco. O cultivar Catuaí 15 foi mais eficiente na produção de matéria seca e utilização de B e Zn quando combinado com os materiais genéticos de conilon ES 26 e ES 23.

Studying nutritional efficiency of grafted coffee plants is important for the selection of graft/ rootstock combinations, aiming to achieve better plant development and yield. The objective of this work was to evaluate the genetic differences for B, Zn, Cu and Mn absorption and utilization efficiencies of grafted coffee seedlings. The experiment was conducted with seedlings planted in 20 L pots with a substrate consisting of soil, sand, and manure in the proportion of 3:1:1, in which they kept for 18 months, until harvest. Four genotypes of Coffea arabica L. were used as grafts: cultivars Catuaí Vermelho IAC 15 ('Catuaí 15) and Oeiras MG 6851 ('Oeiras'), and hybrids H419-10-3-4-4 ('H419') and H514-5-5-3 ('H514'). All genotypes were obtained from the EPAMIG/UFV breeding program. Five half-sibling progenies of clones of Coffea canephora Pierre ex Froenher cv. Conilon were used as rootstocks: 'ES 21', 'ES 36', 'ES 26', 'ES 23' and 'ES 38, which were obtained from the INCAPER robusta coffee breeding program. The experiment was arranged in a complete randomized design, with 24 treatments and 3 repetitions, using four control plants and 20 grafting combinations. The nutritional efficiency of coffee plants varied according to the graft/rootstock combination. Considering that all combinations promoted dry matter yield decrease when compared with the respective non-grafted plants, cultivar Oeiras MG 6851 was not benefited by any graft. Cultivar Catuaí Vermelho IAC 15 was more efficient in dry matter production and Cu and Mn utilization when combined with conilon rootstocks 'ES 26' and 'ES 23'.

Com este trabalho, objetivou-se verificar a influência da aplicação de ciproconazol+tiametoxam, via solo, no crescimento de mudas clonais de cafeeiro conilon que compõem cultivar clonal 'Vitória Incaper 8142'. O experimento foi conduzido em vasos e sob condições de ambiente controlado. Utilizou-se delineamento inteiramente casualizado, com distribuição fatorial de 13x2, com quatro repetições, sendo os fatores: 13 clones que compõem a cultivar clonal 'Vitória Incaper 8142'; tratados e não tratados com ciproconazol+tiametoxam. Nas condições avaliadas, as mudas de todos os clones apresentaram, crescimento inferior e sintomas variados de fitotoxidade, influenciados pela aplicação via solo de ciproconazol+tiametoxam.

In order to assess the influence of the cyproconazole + thiamethoxam, into the soil, the growth of clonal coffee conilon comprising clonal cultivar 'Vitória Incaper 8142'. The experiment was conducted in pots and under greenhouse conditions. We used a completely randomized design with factorial distribution of 13x2 with four replications, being the factors: 13 clones that comprise the clonal cultivar 'Vitória Incaper 8142'; treated and untreated with cyproconazole + thiamethoxam. Evaluated conditions, the seedlings of all clones were lower and varied symptoms of phytotoxicity, influenced by the application via soil cyproconazole + thiamethoxam.