Pesquisa Agropecuária Brasileira
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/9886
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60 resultados
Resultados da Pesquisa
Item Multitemporal variables for the mapping of coffee cultivation areas(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2019) Souza, Carolina Gusmão; Arantes, Tássia Borges; Carvalho, Luis Marcelo Tavares de; Aguiar, PolyanneThe objective of this work was to propose a new methodology for mapping coffee cropping areas that includes multitemporal data as input parameters in the classification process, by using the Landsat TM NDVI time series, together with an object-oriented classification approach. The algorithm BFAST was used to analyze coffee, pasture, and native vegetation temporal profiles, allied to a geographic object-based image analysis (GEOBIA) for mapping. The following multitemporal variables derived from the R package greenbrown were used for classification: mean, trend, and seasonality. The results showed that coffee, pasture, and native vegetation have different temporal behaviors, which corroborates the use of these data as input variables for mapping. The classifications using temporal variables, associated with spectral data, achieved high-global accuracy rates with 93% hit. When using Only temporal data, ratings also showed a hit percentage above 80% accuracy. Data derived from Landsat TM time series are efficient for mapping coffee cropping areas, reducing confusion between targets and making the classification process more accurate, contributing to a correct characterization and mapping of objects derived from a RapidEye image, with a high spatial solution.Item Geographical distribution of the incubation period of coffee leaf rust in climate change scenarios(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2019) Alfonsi, Waldenilza Monteiro Vital; Coltri, Priscila Pereira; Zullo Júnior, Jurandir; Patrício, Flávia Rodrigues Alves; Gonçalves, Renata Ribeiro do Valle; Shinji, Kaio; Alfonsi, Eduardo Lauriano; Koga-Vicente, AndreaThe objective of this work was to simulate the geographical distribution of the incubation period of coffee leaf rust in Coffea arabica, using data of two regional climate models, Eta-HadGEM2-ES and Eta- MIROC5. The scenario of high greenhouse gas emission (RCP 8.5 W m-2) was used for the states of Minas Gerais and São Paulo, Brazil, for current and future climate scenarios. The behavior of six different regression equations for incubation period (IP), available in the literature, was also analyzed as affected by data from the regional climate models. The results indicate the possibility of an increase in the affected area in the studied region, When the IP is less than 19 days, from 0.5% for Eta-MIROC5 to 14.2% for Eta- HadGEM2-ES. The severity of coffee leaf rust in future scenarios should increase in the hottest and wettest months of the year, extending to the driest and coldest months. The potential of rust infection is estimated differently by the studied equations. In higher temperature scenarios, the Kushalappa & Martins equation indicates a very high severity potential.Item Arabica coffee response to rates of coated and conventional urea in sandy soil(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2019) Abranches, Jorge Luiz; Soratto, Rogério Peres; Perdoná, Marcos José; Parecido, Renan JoséThe objective of this work was to evaluate the growth, relative chlorophyll index and nitrogen concentrations in leaves, and the grain yield of arabica coffee (Coffea arabica) fertilized with rates of N as coated and conventional urea, in a sandy soil under rainfed conditions. The experimente was carried out over three crop years, using 'Mundo Novo IAC 388-17-1' coffee, in a randomized complete block design, in a 3×2+1 factorial arrangement, with three treatments with 150, 300, and 600 kg ha-1 N, as coated and conventional urea, and a control without N, with six replicates. Nitrogen increased stem diameter, plant height, N concentrations and relative chlorophyll index in the leaves, as well as grain yield. Over the three crop years, the highest N rate provided the greatest grain yield. Coated urea has no advantage over the conventional one, in supplying N to arabica coffee crop, in sandy soil under rainfed conditions.Item Difference between isolates from brown eye spot and black spot lesions in coffee plants(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2019) Botelho, Deila Magna dos Santos; Resende, Mário Lucio Vilela de; Rezende, Juliana Costa de; Ribeiro Júnior, Pedro Martins; Andrade, Camila Cristina Lage de; Alves, Eduardo; Amaral, Douglas CarvalhoThe objective of this work was to evaluate the difference between the isolates from two cercospora leaf spot symptoms (brown eye spot and black spot) in relation to conidial morphology, mycelial growth, cercosporin production, and reproduction of symptoms in coffee leaves collected in three municipalities in the state of Minas Gerais, Brazil. There was a difference between the isolates for the studied variables, but without any relation to the type of symptom. The differences found were not associated with the origin of the isolates. The symptoms characterized as black spot were associated with different host conditions during the infection process.Item Genetic variability in conilon coffee related to grain attributes in an irrigated crop in the Cerrado(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2019) Brige, Felipe Augusto Alves; Celestino, Sonia Maria Costa; Amabile, Renato Fernando; Fagioli, Marcelo; Delvico, Francisco Marcos dos Santos; Montalvão, Ana Paula Leite; Sala, Pedro Ivo Aquino LeiteThe objective of this work was to quantify the genetic variability of 213 conilon coffee accessions of the Robusta Tropical cultivar, based on Chemical characteristics related to the quality of green coffee beans, as well as to identify promising accessions for the breeding program of irrigated conilon coffee in the Brazilian Cerrado. The chemical characteristics evaluated were: protein and caffeine contents, total soluble solids and total lipids, ether extract, pH, and total titratable acidity. The data were subjected to the principal componente analysis and cluster analysis based on the similarities observed within the first two principal components using the minimum variance method (Wards) and, as a measure of similarity, the Euclidean distance. The three main componentes explained 72.64% of the total variation of the data. All characteristics, except pH, were correlated with the first three components. It was possible to separate the genotypes in three clusters, according to the similarities observed in the behavior of the variables. The evaluated accessions present genetic variability regarding the assessed quality characteristics of green coffee beans, and CPAC 160 and CPAC 32 are the most promising for the breeding program of conilon coffee for cultivation under irrigation in the Cerrado.Item Sensory profile of conilon coffee brews from the state of Espírito Santo, Brazil(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2018-09) Mori, André Luiz Buzzo; Garcia, Aline de Oliveira; Ferrão, Maria Amélia Gava; Fonseca, Aymbiré Francisco Almeida da; Ferrão, Romário Gava; Benassi, Marta de ToledoThe objective of this work was to present a sensory description of conilon coffee (Coffea canephora) brews produced from genotypes developed for the state of Espírito Santo, Brazil. The genotypes 'Diamante ES8112', 'ES8122', and 'Centenária ES8132' were evaluated. Nine samples from three clones (genotypes) of each cultivar, from two different regions of the state, were analyzed. A panel of tasters for coffee sensory evaluation was trained to obtain a descriptive profile and to select terms. Beverages were described as showing a higher intensity of powder fragrance, characteristic aroma of coffee brew, body, characteristic flavor and aftertaste, and a lower intensity of bitterness, acidity, astringency, and defects. The terms bitterness, strong, body, astringency, and coffee aftertaste were the most relevant in the characterization of the beverages of the studied C. canephora cultivars. Acidity is the attribute with the greatest impact on the overall quality of C. canephora brew. The coffee brews of the clones of 'Diamante ES8112', 'ES8122', and 'Centenária ES8132' are classified as of traditional quality, but near the superior category.Item Impacts of water availability on macronutrients in fruit and leaves of conilon coffee(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2018-09) Covre, André Monzoli; Partelli, Fábio Luiz; Bonomo, Robson; Tomaz, Marcelo Antônio; Ramalho, José CochichoThe objective of this work was to evaluate the concentrations and accumulation of macronutrients in conilon coffee (Coffea canephora) fruit, and their concentrations in leaves, over two years, in irrigated and nonirrigated coffee plants. Three-year-old conilon coffee plants of the cultivar Emcapa 8111 genotype 02 were used. An experimental design was carried out in randomized complete blocks, in a split-plot arrangement, with 14 replicates. The main plot factor was irrigation versus nonirrigation of coffee plants, and the split-plot factor was different fruit and leaf collection times. Collections began 10 days after the beginning of flowering and were performed on average every 28 days, until full fruit ripening. At each sampling date, five plants per treatment were picked out, by collecting one plagiotropic branch by plant, separated into fruit and leaves. Each part was dried, weighed, and subjected to the chemical analysis. Macronutrient accumulations and their accumulation rates were determined. According to the regression analysis of the data, fruit macronutrient accumulation curves fit best to sigmoidal equations. Irrigation affects the macronutrient dynamics in fruit and leaves during the fruiting phase of conilon coffee, and increases the accumulation of nutrients in the plant tissues. The macronutrients found in greater quantities are N, K, and Ca, in fruit and leaves, regardless of the irrigation treatment.Item Forecasting of the annual yield of Arabic coffee using water deficiency(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2018-12) Aparecido, Lucas Eduardo de Oliveira; Rolim, Glauco de SouzaThe objective of this work was to develop agrometeorological models for the forecasting of the annual yields of Arabic coffee (Coffea arabica), using monthly water deficits (DEFs) during the coffee cycle, in important locations in the state of Minas Gerais, Brazil. For the construction of the models, a meteorological data set spanning of 18 years and multiple linear regressions were used. The models were calibrated in high‐ and low-yield seasons due to the high-biennial yields in Brazil. All calibrated models for high- and low-yield seasons were accurate and significant at 5% probability, with mean absolute percentage errors ≤2.9%. The minimum forecasting period for yield is six months for southern Minas Gerais and Cerrado Mineiro. In high‐yield seasons, water deficits affect more the reproductive stage of coffee and, in low-yield seasons, they affect more the vegetative stage of the crop.Item Alternative sources of potassium in coffee plants for better soil fertility, productivity, and beverage quality(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2018-12) Dias, Kaio Gonçalves de Lima; Guimarães, Paulo Tácito Gontijo; Carmo, Davi Lopes do; Reis, Thiago Henrique Pereira; Lacerda, Julian Junio de JesusThe objective of this work was to evaluate alternative sources of potassium for improving soil fertility and coffee productivity and beverage quality. The experiment was conducted in a coffee (Coffea arabica) crop, planted in an Oxisol area, in the municipality of Patrocínio, in the state of Minas Gerais, Brazil. The treatments consisted of the K sources TK47 and Super Greensand (SG) – both based on glauconite silicate mineral –, at the following doses: 0 kg ha-1K2O (control); 42, 84, 168, and 336 kg ha-1K2O from TK47; 618 kg ha-1K2O from KCl; and 168 kg ha-1K2O from SG. A randomized complete block design was used, with four replicates in each treatment. The experimental units consisted of three rows with ten plants each, using the eight central plants as the useful plot. Potassium fertilization with TK47 increased soil fertility, correcting soil acidity and elevating K + , P, and Ca 2+ contents, effective cation exchange capacity, and Zn 2+ and Fe 2+ levels in the soil. Fertilization with 336 kg ha-1K2O from TK47, in a single dose, provides grain yield and polyphenol oxidase activity similar to those of fertilization with 618 kg ha-1K2O from KCl, in a split-dose, but a better sensory analysis of the resultant beverage.Item Alterações fisiológicas e bioquímicas em sementes de café secas em sílica gel e soluções salinas saturadas(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2015-06) Coelho, Stefania Vilas Boas; Figueiredo, Madeleine Alves de; Clemente, Aline da Consolação Sampaio; Coelho, Luis Filipe Serafim; Rosa, Sttela Dellyzete Veiga Franco daO objetivo deste trabalho foi avaliar alterações fisiológicas e bioquímicas em sementes de café submetidas à secagem rápida, em sílica gel, e à secagem lenta, em soluções salinas saturadas. As sementes foram secas até que atingissem os seguintes teores de água: 40, 30, 20, 15, 10 e 5% (base úmida). Após a secagem, uma parte das sementes foi imediatamente avaliada quanto ao desempenho fisiológico e ao perfil de enzimas do processo oxidativo, e outra parte foi avaliada após armazenagem em condição hermética, em câmara fria e seca, por quatro meses. A velocidade de secagem e o teor final de água tiveram efeito significativo sobre a qualidade fisiológica das sementes. Após a secagem rápida em sílica gel, as sementes toleraram teores finais de água mais baixos. No entanto, após a secagem lenta, as sementes com teores finais de água mais elevados apresentaram maior qualidade. O período de armazenamento não afetou a germinação, mas prejudicou o vigor das sementes. A secagem rápida apresenta maior potencial de dano ao endosperma do que aos embriões. O perfil enzimático das sementes de café é afetado pelo teor final de água e pela velocidade de secagem.