Coffee Science
URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3355
Navegar
3 resultados
Resultados da Pesquisa
Item Coffee genotypes morphophysiological adaptation under coffee leaf rust biotic stress(Editora UFLA, 2021) Viana, Mariana Thereza Rodrigues; Azevedo, Harianna Paula Alves de; Pereira, Fernanda Aparecida Castro; Carvalho, Milene Alves de Figueiredo; Guimarães, Rubens JoséThe identification of morphophysiological traits responsible for a better plant behavior when infected is useful for cultivar selection, and become crucial for breeding. We investigated the morphophysiological behavior of coffee genotypes before and after inoculation with the pathogen Hemileia vastatrix, causal agent of coffee rust. With multivariate techniques we identified the characteristics that most contribute to total genetic divergence of the geno types. Ten genotypes of Coffea arabica from the Germplasm Bank of Coffee from Minas Gerais were sown in a nursery and then take to a greenhouse with controlled temperature and humidity. After one month of acclimatization, the artificial inoculation with the fungus H. vastatrix was carried out. The anatomical and physiological evaluations were performed 1 day before inoculation and 160 days after inoculation. When the first symptom emerged, plants were evaluated according to a descriptive scale for coffee rust. We observed significant differences in rust severity and ostiole opening between genotypes. Different groups were formed by the K-means method, based on morphophysiological characteristics. This shows that genetic variability exists between the coffee genotypes evaluated before and after inoculation with the pathogen. The most important characteristics that contributed to the total genetic divergence were xylem vessel diameter and stomatal conductance. In conclusion, inoculation with H. vastatrix caused a change in coffee geno types based on morphophysiological characteristics.Item Rooting biostimulants for Coffea arabica L. cuttings(Editora UFLA, 2020) Azevedo, Harianna Paula Alves de; Carvalho, Alex Mendonça de; Vidal, Douglas Alves; Santos, Heloisa Oliveira dos; Doria, JoyceIn the rooting process of Arabica coffee cuttings, plant hormones are used for inducing root formation. However, synthetic molecules cannot be used to form organic seedlings. The objective of this work was to evaluate the effect Cyperus haspan extract and different concentrations and types of humic substances on Arabica coffee cuttings. Arabica coffee shoots were collected, and cuttings containing at least two buds were taken. The experiment had a three-factor design, 2 (presence or absence Cyperus haspan extract) x 2 (humic or fulvic acid) x 4 (0, 10, 25 and 50 mg dm-³ concentrations). The following vegetative data were evaluated: shoot height (cm), survival, remaining leaves, leaf pairs, vigor, number of shoots,root length, area root, volume root, diameter root and fresh and dry mass were also evaluated. The enzyme activity of H+-ATPase, catalase, superoxide dismutase, alcohol dehydrogenase and esterase was also quantified. The results showed that the Arabica coffee cutting rooting rate was increased when treated with humic acid at a concentration of 10 mg dm-³ in the presence of Cyperus haspan extract. The lowest oxidative stress was observed in the 10 mg.dm-³ humic and fulvic acid treatments, regardless of the use of the extract.Item Anatomia foliar, fisiologia e produtividade de cafeeiros em diferentes níveis de adubação(Editora UFLA, 2017-01) Gama, Tamara Cubiaki Pires da; Sales Junior, José Carlos; Castanheira, Dalyse Toledo; Silviera, Helbert Rezende de Oliveira; Azevedo, Harianna Paula Alves deA nutrição mineral é importante para o desenvolvimento da estrutura interna das folhas do cafeeiro, podendo favorecer as características fisiológicas necessárias para otimizar o desenvolvimento e a produtividade da cultura. Objetivou- se identificar as possíveis modificações na anatomia, fisiologia e produtividade em cafeeiros irrigados em diferentes níveis de adubação aplicados em três anos consecutivos, a partir do segundo ano após a implantação da lavoura. A lavoura de Coffea arabica cultivar Topázio MG-1190 foi formada seguindo a recomendação padrão de Guimarães et al. (1999) para adubação em função de análise do solo, até o primeiro ano após implantação (2010-2011). A partir daí, no segundo ano após a implantação (2011-2012), os níveis de adubação utilizados foram: 40, 70, 100, 130 e 160% da adubação padrão. Repetiram-se os tratamentos nos anos de 2012-2013 e 2013-2014. As plantas foram avaliadas quanto às trocas gasosas e anatomia foliar em agosto de 2014. Também foi avaliada a produtividade dos anos de 2013 e 2014. Os diferentes níveis de adubação NPK provocaram diferenças na anatomia foliar do cafeeiro. A produtividade e trocas gasosas do cafeeiro não foram afetadas pelos diferentes níveis de adubação NPK.