Coffee Science
URI permanente desta seção${dspace.url}/handle/123456789/3355
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Resultados da Pesquisa
Item New vegetation index for monitoring coffee rust using sentinel-2 multispectral imagery(Universidade Federal de Lavras, 2023-12-29) Castro, Gabriel Dumbá Monteiro de; Vilela, Emerson Ferreira; Faria, Ana Luísa Ribeiro de; Silva, Rogério Antônio; Ferreira, Williams Pinto MarquesCoffee Rust (Hemileia vastatrix) is considered the primary coffee disease in the world. The pathogenic fungus can find favorable environmental conditions in different countries, constantly threatening coffee producers. The previous detection of the incidence of coffee rust in a region is crucial because it provides an overview of the disease’s progress aiding in coffee plantations management. The objective of this work was the development of a vegetation index for remote monitoring of coffee rust infestation. Using satellite images from the MSI/Sentinel-2 collection, the Machine Learning classifier algorithm - Random Forest, and the cloud processing platform - Google Earth Engine, the most sensitives bands in coffee rust detection were determined, namely B4 (Red), B7 (Red Edge 3) and B8A (Red Edge 4). Thus, the Triangular Vegetation Index method was used to create a new vegetative index for remote detection of coffee rust infestation on a regional scale, named Coffee Rust Detection Index (CRDI). A linear regression model was created to estimate rust infestation based on the performance of the new index. The model presented a coefficient of determination (R²) of 62.5%, and a root mean square error (RMSE) of 0.107. In addition, a comparison analysis of the new index with eight other vegetative indices commonly used in the literature was carried out. The CRDI obtained the best performance in coffee rust detection among the others. This study shows that the new index CRDI has the robustness and general capacity to be used in monitoring coffee rust infestation on a regional scale.Item Histochemical approach of the mobilization of reserve compounds in germinating coffee seeds(Editora UFLA, 2020) Oliveira, Leonardo Araujo; Souza, Genaina Aparecida de; Silva, Bruno Tavares; Rocha, Antônio Augusto Gomes; Picoli, Edgard Augusto de Toledo; Pereira, Diego de Sousa; Donzeles, Sérgio Maurício Lopes; Ribeiro, Marcelo de Freitas; Ferreira, Williams Pinto MarquesThe endosperm of coffee beans is an important structure which is composed of different reserve compounds. In the present study, we followed anatomical features during the reserve mobilization of Coffea arabica L. cv ‘Catuaí’ seed samples, harvested at 20 different sites, after 0, 3, 6, 12, 24, 30 and 45 days of imbibition. Seed samples were properly stored for enzyme activity assessment and fixed in FAA solution (formaldehyde, acetic acid and ethanol, 1; 1; 18) and kept in ethanol 70% solution, for histochemical analysis. Alternatively, samples for phenolic compounds histochemical test were fixed in Ferrous sulfate in formalin. Fixed samples were cross-sectioned for detection of starch, lipids, essential oils, oleoresins, proteins, phenolic compounds, neutral polysaccharides, alkaloids, β-1,3 and β-1,4 glucans, and lignin. Overall, based on histochemical tests and enzyme activity, seed reserve mobilization was similar among the evaluated altitudes and mountainsides. During soaking, there is an intense consumption of reserve compounds, starting at the region close to the embryo. Reserve mobilization intensifies after root protrusion, from 12 days of soaking. The intensification of the reserve consumption concomitant with an increased activity of MDH is observed at the first 12 days, whereas SOD showed higher expression after 30 days of soaking. At the 30th day, little reserve is observed in the endosperm. At 45th day, cotyledon leaves are expanded, and the root system, constituted by the taproot and lateral roots, is well established.Item Ambiente e variedades influenciam a qualidade de cafés das matas de Minas(Editora UFLA, 2017-04) Zaidan, Úrsula Ramos; Corrêa, Paulo Cesar; Ferreira, Williams Pinto Marques; Cecon, Paulo RobertoO café é um produto agrícola que tem seu valor de mercado ajustado de acordo com a qualidade final da bebida, que pode ser influenciada por vários fatores, tais como: fatores ambientais e variedade. Diante disso, objetivou-se com este trabalho avaliar os efeitos da orientação da encosta da montanha, altitude e variedade da planta, sobre a qualidade potencial dos cafés produzidos na região das Matas de Minas (entre altitudes que variam de 600 a 1200 m). Frutos de café (Coffea arabica) das variedades “Catuaí Vermelho” e “Catuaí Amarelo”, provenientes de 14 municípios da região, foram colhidos manualmente no ponto de maturação fisiológica, os quais foram processados, beneficiados e armazenados. Em seguida foram feitas análises descritivas qualitativas por Juízes Certificadores, pelo teste de degustação segundo critérios da Brazil Specialty Coffee Association. Por meio da análise sensorial da bebida, foram atribuídas notas aos atributos de qualidade dos cafés objetivando classificá-los de acordo com a influência dos fatores do ambiente e da variedade. Para análise das notas foi adotada a “Estatística Descritiva” e o “Método de Tocher”. A partir dos resultados obtidos, pode-se observar que os fatores ambientais e a variedade não exercem influência sobre a qualidade da bebida de forma isolada, todavia, contribuem de forma conjunta para formar as características da bebida produzida na região. A maior pontuação média foi obtida pela combinação de fatores, variedade “Catuaí Amarelo” estrato de altitude abaixo de 700 m e encosta Noruega da montanha, mostrando grande potencial de expressão da qualidade sensorial da bebida.