Coffee Science_v.16, 2021
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/12727
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Item Water retainer polymer in coffee plants deployment under different levels of irrigation(Editora UFLA, 2021) Resende, Thales Barcelos; Souza, Victor Hugo Silva; Castanheira, Dalyse Toledo; Carvalho, Milene Alves de Figueiredo; Guimarães, Rubens JoséThe use of water-retaining polymers may be a feasible alternative in regions with low water availability, as they has enhance the performance of coffee plants with more favorable anatomical characteristics to make physiological processes more efficient. However, the advantages of such use have been scarcely reported. Here, we studied the feasibility of using a water-retaining polymer to optimize irrigation water use during the establishment of a coffee plantation. A randomized block design was used in a factorial scheme (4 × 2) with three replications for a total of 24 experimental plots, each consisting of four pots, with one plant per unit. The experiment was installed in a greenhouse at the Coffee Science Department of the Universidade Federal de Lavras, Minas Gerais, Brazil, with four levels of irrigation (25%, 50%, 75%, and 100% of soil water at field capacity), with or without addition of the water-retaining polymer. Growth variables evaluated included: plant height, stem diameter, number of leaves, shoot and root dry weights, root volume and area. Additionally, gas exchange, leaf water potential, and leaf anatomy were analyzed. The use of water-retaining polymer during establishment of the coffee plantation ensured sufficient water supply, thus guaranteeing plant anatomical and physiological functionality and, consequently, a healthy, vigorous growth.Item Leaf anatomy, physiology and vegetative growth of fertigated Coffee arabica L. trees after exposure to pruning(Editora UFLA, 2021) Soares, Daiane dos Santos; Silva, Elisângela Aparecida da; Carvalho, Milene Alves de Figueiredo; Pereira, Fernanda Aparecida Castro; Guimarães, Rubens JoséIn coffee plants, fertigation can be an alternative way to minimize the negative effects exerted by drought and maximize fertilizer use efficiency. However, the fertilization recommendations for fertigated coffee trees are still not very specific, and the recommendations for rainfed crops are used. In addition, little is known about the nutritional requirements for fertigated coffee trees that have undergone the low recepa pruning treatment. Thus, the objective of this study was to evaluate the effects of different levels of nitrogen (N), phosphorus (P), and potassium (K) fertilizers on leaf anatomy, physiology, and veg etative growth of fertigated coffee trees (Coffea arabica L.) that have been under the low recepa pruning treatment. During the first five years of growth, the cultivar Topázio MG-1190 of the coffee crop received 10, 40, 70, 100, 130, and 160% of the fertilization levels recommended for the rainfed coffee crop. After this period, the crop was exposed to low recepa pruning. It was concluded that different doses of N, P, and K fertilizers modified the internal structure of coffee plant leaves, as well as physiological responses and plant growth; there was stronger vegetative growth, sharper leaf blade, greater thickness of spongy parenchyma, larger phloem area, and higher xylem relative hydraulic conductivity as the N, P, and K fertilizer levels in fertigated coffee (Coffea arabica L.) plants, which received the low recepa pruning treatment, increased. This knowledge can be used as a solid basis for main fertilization recommendations for fertigated coffee trees after exposure to the low recepa pruning treatment.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.