Estudo da influência da época de coleta dos ramos, no enraizamento de etacas caulinares de café (Coffea arabica L. cv Mundo Novo)

Na propagação vegetativa através de estacas caulinares, a época de retirada dos ramos, que serão utilizados na confecção das estacas, tem grande influência sobre seu enraizamento. Outro fator de grande relevância é o tratamento auxínico, realizado nas estacas, que promove a formação de raízes. O presente trabalho teve como objetivo, verificar a ação das auxinas e do boro e a influência da época de coleta dos ramos de cafeeiro, sobre o enraizamento de ramos ortotrópicos semi-lenhosos de café (Coffea arabica L. cv Mundo Novo). Para tal, o experimento foi montado mensalmente, realizando-se as seguintes medidas , mediante coleta das estacas, após 90 dias do plantio: número de estacas enraizadas e número total de raízes formadas. À partir dos resultados obtidos, concluiu-se que, a melhor época de coleta dos ramos é na estação chuvosa. Além disso, tratamentos com NAA à 200 ppm mais boro, também promovem uma alta porcentagem de enraizamento.

Microscopia eletrônica de varredura do endosperma de café (Coffea arabica L.) durante o processo de secagem

A manutenção da integridade das membranas celulares, entre outros eventos, é um forte indicativo de que a qualidade do café foi preservada na pós-colheita. Objetivou-se neste trabalho, analisar o efeito de diferentes métodos de secagem na manutenção da integridade da parede celular e da membrana plasmática de café natural e café despolpado, buscando determinar as condições e o momento em que ocorrem as rupturas microscópicas. Os cafés foram submetidos a um período de pré-secagem em terreiro. Após este, uma parcela de cada tipo de café foi desidratada no terreiro e, outra, à temperatura de 40ºC e 60ºC em secadores de camada fixa, monitorando-se a temperatura e o teor de água até 11% (bu). Nesse período, grãos foram aleatoriamente amostrados e fragmentos do endosperma preparados para a microscopia eletrônica de varredura, registrando-se diversas eletromicrografias, avaliando-se as alterações na membrana plasmática da célula do endosperma dos grãos de cafés em função do teor de água e tempo de secagem. O citoplasma das células a 11% (bu) de teor de água não foi comprometido na secagem em terreiro e a 40°C; na secagem a 60°C, observou-se comprometimento nas estruturas celulares nos cafés com teor de água de 20% (bu).

Atrativo para as abelhas Apis mellifera e polinização em café (Coffea arabica L.)

O presente experimento foi conduzido em Jaboticabal, SP, e teve como objetivos estudar uma cultura de café (Coffea arabica L., var. Mundo Novo), quanto à biologia floral, a freqüência e comportamento dos insetos na flor, testar o produto Bee-HereR (Hoescht Shering Agrevo do Brasil Ltda) quanto a sua atratividade para as abelhas Apis mellifera e verificar a produção de frutos com e sem a visita dos insetos. Para isso, foram verificados o tempo do desenvolvimento e quantidade de açúcar solúvel do néctar das flores; freqüência das visitações dos insetos, no decorrer do dia, por meio de contagem do número de insetos visitando as flores, a cada 60 minutos, das 8 às 17 horas, 10 minutos em cada horário; tempo (em segundos) e tipo de coleta (néctar e/ou pólen) dos insetos mais freqüentes; perda de botões florais; porcentagem de flores que se transformaram em frutos; tempo de formação e contagem dos grãos de café, observando-se a porcentagem de frutificação em flores visitadas ou não pelos insetos. Também foram realizados testes por pulverização utilizando-se o produto Bee-HereR , diluído em xarope e em água, em diferentes horários. A flor durou, em média, cerca de 3 dias desde sua abertura até o murchamento. A quantidade de açúcares do néctar apresentou diferença significativa entre os horários, sendo maior às 8 horas (em média, 102,18 ± 8,75 mg de carboidratos totais por flor). A abelha A. mellifera foi o inseto mais freqüente nas flores de café, coletando, principalmente, néctar no decorrer do dia. A perda de botões florais causada pelas chuvas foi, em média, 26,50 ± 11,70%. O tempo para a formação do fruto foi 6 meses e o número de frutos decorrentes do tratamento descoberto foi maior (38,79% e 168,38%, em 1993 e 1994, respectivamente) que do tratamento coberto. Apesar da eficiência do produto Bee-HereR ser afetada pelas condições climáticas, ele pode ser usado para atrair as abelhas A. mellifera na cultura.

Action of auxins and/or boron, in the process of formation of roots in cuttings of coffee (Coffea-Arabica L CV Mundo-Novo)

The objective of present research was to verify the IBA and/or NAA effects with boron, on rooting of coffee (Coffea arabica L. cv 'Mundo Novo') stem cuttings. Therefore it were used stem cuttings from semi-hardwood orthotropous branches, having two nodes, with aproximately 10 cm of lenght. The cuttings were treateds during 24 hours with IBA and/or NAA plus boron solutions. The treatments' effect was observed trough the following observation, 90 days after planting: rooting percentage and number of cuttings with ''callus''. Trough the resultS obtained, it was concluded that, for obtaining more rooting of cuttings, the best treatment was NAA at 200 ppm plus boron or, the combination of IBA and NAA at 200 ppm plus boron.

The effect of chilling on the photosynthetic activity in coffee (Coffea arabica L.) seedlings. The protective action of chloroplastid pigments

Coffea arabica is considered to be sensitive to low temperatures, being affected throughout its entire life cycle. Injury caused by chilling (low temperatures above zero degree centigrade) is characterized primarily by inhibition of the photosynthetic process. The objective of this work was to evaluate the role of photosynthetic pigments in the tolerance of coffee (C. arabica L.) seedlings to chilling. The evaluation the photosynthetic activity was made by emission of Chl a fluorescence at room temperature (25°C) in vivo and in situ, using a portable fluorometer. The pigment content was obtained by extraction with 80% acetone, while estimation of membrane lipid peroxidation was determined by measuring the MDA content in leaf tissue extracts. The results indicated a generalized reduction in the quantum yield of PSII when the seedlings were maintained in the dark. The reduction occurred in the seedlings submitted to chilling treatment as well as in the control ones. This demonstrates that not only chilling acts to cause an alteration in PSII. It is possible that the tissue storage reserves had been totally exhausted, with the respiratory rate exceeding the photosynthetic rate; the later was nil, since the seedlings were kept in the dark. The efficiency in the capture, transfer and utilization of light energy in PS11 photochemical reactions requires a sequence of photochemical, biochemical and biophysical events which depend on the structural integrity of the photosynthetic apparatus. However, this efficiency was found to be related to the protective action of chloroplastid pigments, rather than to the concentration of these pigments.

Effect of the density and of the distance of Brachiaria decumbens staff on the initial growth of Coffea arabica L. Seedligns

The aim of this work was to evaluate the interference of three densities (4, 8 and 16 plants/m 2) of Brachiaria decumbens Stapf distributed at three different distances (0, 10 and 20 cm from coffee plants) on the initial growth of Coffea arabica L. seedlings. Dark red Latosoil was used as substrate to fill up 70 liters cement boxes. Coffee seedlings at 15 cm height and 8 leaves stage were planted in each box. B. decumbens seedlings were transplanted when they reached two to four leaves stage. The experimental design was a randomized blocks with ten treatments and three replications. At the end of the experiment were measured, height, leaf number, leaf area, chlorophyll content and dry weight of coffee plants. Dry weight of B. decumbens leaves was also evaluated. The leaf area and leaf dry weight was shown to be more sensitive parameters to the interference of Brachiaria plants. Dry weight of coffee plants were reduced from 60% to 88% when the B. decumbens were transplanted 0 cm from the coffee plant. With distance of 10 cm the reduction of dry weight increased with the increase of the density of the B. decumbens. In the coexistence of the coffee plants with 16 plants/m 2 of B. decumbens, there was a reduction in the dry weight of about 80% at the distances of 0 and 20 cm. Regarding leaf area, the reduction was 47% on the average in the density of 4 plants/m 2 of B. decumbens The reduction in leaf area at other densities was higher at the distance of 0 and 20 cm, and 55% reduction was obtained at the distance of 10 cm.

Drosofilídeos e seus himenópteros parasitoides em coffea arabica L

The objective of this study was to evaluate the occurrence of Drosophilidae and their parasitoids in coffee fruits in Cravinhos, SP, Brazil. The fruits were collected directly from the tree, and a portion was exposed under the canopy. Fifty-nine drosophilid pupae were collected in all, of which 31 adults (including two Ganaspis exemplars) emerged. The survival rate of all pupae was 49.2%. Thirty-five drosopholid pupae were obtained from the fruit trees, 24 of which later emerged, three different species: Zaprionus indianus Gupta, Drosophila nebulosa Sturtevant and D. simulans Sturtevant. From the fruits under the canopy of plants were obtained 24 pupae of four different species: Z. indianus, D. cardini Sturtevant, D. immigrans Sturtevant and D. willistoni Sturtevant. The emergence of two Ganaspis sp. (Hymenoptera: Figitidae) examples, with a parasitism rate of 8.3%, was also observed. Half of the drosophilids collected are introduced species and represented 79% of the adults emerged. Associations between Z. indianus, D. cardini, D. immigrans, D. nebulosa, D. simulans and D. willistoni and the coffee crop are reported herein.

Variabilidade espacial de atributos químicos do solo cultivado com café arábica (Coffea arabica L.) sob diferentes manejos

The objective of this work was to assess the spatial variability of the chemical attributes of two coffee areas, managed in conventional and organic crop systems, and to calculate the percent of variation between them. In each area, a 40-point-mesh was sampled at 0-0.10 m and 0.10-0.20 m layers, within the crown projection, for pH, SB, K, P, Ca and Mg analysis. The data were analyzed through descriptive statistics and geostatistics. From the soil chemical attributes map, the percent of variation between the systems' chemical attributes was determined by GIS algebraic operations. The results show that the soil chemical attributes present a spatial dependence in both systems and layers. Analysis of the soil chemical attributes showed less spatial variability in the organic system, in relation to the conventional, indicating homogeneous zones for different fertilizer applications. The percent of variation of the chemical attributes in the conventional system, in relation to the organic, at 0-0.10 m and 0.10-0.20m layers are 54.80% and 35.61%, respectively.

Novos registros de Entedoníneos (Hymenoptera, Eulophidae) para a cultura do café (Coffea arabica L.)

The first cases of Emersonella pubipennis Hansson, 2002, Emersonella planiceps Hansson, 2002, Omphale huggerti (Hansson, 1988), Chrysocharis caribea Boucek, 1977, Chrysocharis vonones (Walker, 1839) and Chrysocharis tristis Hansson, 1987 (Hymenoptera, Eulophidae, Entedoninae) were reported for Coffea arabica L. based on specimens collected in Cravinhos (21°18'S/47°47'W), State of São Paulo, Brazil. The first occurrence of E. pubipennis and O. huggerti were also reported in Brazil. The insects were collected with Moericke and light traps between May of 2005 and April of 2007.

Nitidulidae (Coleoptera) Associados A Frutos de Café (Coffea Arabica L.)

This study reports sap beetles from fruits of a coffee crop in Cravinhos, SP, Brazil. Fruits were collected directly from plants and, in laboratory, from the fruits at the cherry state we obtained 20 adults of three species: Carpophilus nepos Murray, 1864, Colopterus niger Murray, 1864 and Nitops sordidus Erichson, 1847. This is the first report of association between these insects and coffee fruits.

Expressão gênica no embrião e no endosperma micropilar de sementes de café (coffea arabica L.) durante a germinação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fontes e doses de potássio na cultura do café (Coffea arabica L.)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência do etileno na regulação do florescimento de Coffea arabica L.

Coffee is one of the most valuable exported agricultural product worldwide as well as the second most traded commodity after oil. This crop represents a source of employment and considerably accounts for the revenue of the country, besides its undeniable importance for local and world socioeconomical scenery. The quality of the coffee drink is directly related to the fruit ripening stage, which is found in different stages at harvesting due to the sequential flowering, increasing costs with the production and generating a lower-quality beverage. The asynchronous flowering of the coffee tree comes from the uneven development of buds, which can be influenced by environmental factors, taking into account that the anthesis takes place after a water deficit period, followed by precipitation. Changes in the hormone balance have been observed after water deficit and rehydration cycles, and such oscillation on the water status of the plant increased the level of ethylene in some species. This finding led to the association between the requirements at the flowering stage of the coffee tree and the involvement of the ethylene in promoting anthesis. The application of 1- MCP (ethylene action inhibitor) triggered the anthesis in coffee trees. And, in coffee seedlings in greenhouse conditions after a period of water shortage followed by irrigation, the profile of gene expression of the biosynthesis route and signaling of ethylene are changed in leaves and roots. The increased levels of the ethylene precursor (ACC) in roots throughout the dry season and the transportation of this compound into shoots may be the signal to trigger the anthesis in coffee tree after rehydration. Thus, in order to better understand the role of the ethylene in regulation of flowering, we analyzed the effects of the exogenous application of 1-MCP in different physiological characteristics and in the expression of genes related to the ethylene biosynthesis and signaling pathways in coffee leaves and bud from plants under field conditions. The evaluations and tissue sampling were carried out in different times treatments implementation: T1 – control, T2 – 1-MCP+Break-Thru, and T3 – Break-Thru. There was influence of 1-MCP and Break-Thru in gas exchange parameters and of 1-MCP contributed to the increase in relative water content. RT-qPCR analyses showed a different behavior in relation to the profile of gene expression in leaves and buds analyzed in the present study (CaACS1 – like, CaACO1 – like, CaACO4 – like, CaETR4 – like) and the expression levels were changed a few hours (2h) after applying the products. However, there was flowering only in plants treated with 1-MCP, in the absence of rain and irrigation.

Espaçamentos para cafeeiro (Coffea arabica L.) com e sem irrigação em região de cerrado

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)