ABSTRACT Phosphorus is a major limiting nutrient for crops in tropical regions. In addition, another major challenge for the future agriculture will be to maintain water levels in the soil to ensure satisfactory crop development. This study inserted in this context aimed to evaluate the conditioning caused by phosphorus fertilization and water availability in the soil over the biomass production and nutritional efficiency of plants of crambe (Crambe abyssinica Hochst). To this end, the experiment was conducted in a greenhouse, with four levels of phosphorus fertilization and three levels of water availability, along of 45 days, in order to obtain information about the production of biomass, nutritional contents, and the patterns of the nutritional efficiency of crambe plants. The results show that increasing the phosphorus supply in the soil promotes greater biomass production in crambe plants. In addition, the increase in water availability and levels of phosphorus fertilization near the recommended level promotes greater nutritional efficiencies in absorb, translocate and use the phosphorus available in the soil.

RESUMEN La disponibilidad de agua y fósforo es una limitante para los cultivos en las regiones tropicales. El objetivo de este estudio fue evaluar el efecto de la fertilización fosfatada y la disponibilidad de agua en el suelo sobre la producción de biomasa y la eficiencia nutricional de las plantas de crambe (Crambe abyssinica Hochst). Las plantas fueron cultivadas en un invernadero, con cuatro niveles de fertilización de fósforo y tres niveles de disponibilidad de agua, para estudiar el comportamiento vegetativo entre emergencia y floración. Se evaluó la biomasa, contenido nutricional y patrones de eficiencia nutricional de las plantas. Los resultados muestran un aumento de biomasa al fertilizar con fósforo. Se observa un efecto sinérgico al aumentar la disponibilidad de agua y fósforo, mejorando la eficiencia en la absorción del fósforo disponible en el suelo.

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).

Crambe is a sensitive specie to exchangeable aluminum, it require a well-fertilized and corrected soil. The objective of this study was to understand the impact of aluminum presence, in different concentrations, in the substrate on the germination and development of crambe. The experiment was carried out as a randomized complete block design with a 5x2 factorial arrangement in four replicates. The five concentrations of Al3+ were 0, 15, 40, 80 and 120 mg dm-3 Al3+ and two temperatures (20 and 30 °C), with four replications. The relative growth rate, plant height, leaf number, total leaf area, specific leaf area, dry matter in each plant compartment (root, stem and leaf), leaf area ratio, stem mass ratio and leaf mass ratio were evaluate. Germination was favored by 20 ºC. The limitation on plant growth was greater as the concentration of aluminum increased, presenting losses in growth, as well of production of dry matter and leaf development, also causing changes in the patterns of biomass allocation between the plant compartments.

Crambe es una especie sensible al aluminio intercambiable que requiere suelos bien fertilizados y corregidos. El objetivo de este trabajo fue evaluar distintas concentraciones de aluminio en la germinación y desarrollo de crambe. El experimento para germinación se realizó con un diseño de bloques completos al azar con arreglo factorial de 5x2, con cuatro repeticiones. Las cinco concentraciones de Al3+ fueron 0, 15, 40, 80 y 120 mg dm-3 y las temperaturas de 20 y 30° C. El experimento para desarrollo de la planta se realizó con un diseño de bloques completos al azar con cinco concentraciones de Al3+ y cuatro repeticiones. Los parámetros evaluados fueron porcentaje de germinación, crecimiento de las plántulas y biomasa. Se analizó la tasa relativa de crecimiento, altura de planta, número de hojas, área foliar total, área foliar específica, materia seca en cada compartimento de la planta (raíz, tallo y hojas), razón de área foliar, razón de masa de raíz, tallo y hojas. El porcentaje de germinación aumentó a los 2 °C. La mayor concentración de aluminio afectó el crecimiento, producción de materia seca y desarrollo de hojas. Estos resultados sugieren que el cramble es sensible al aluminio intercambiable.

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.