Coffee Science_v.16, 2021
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/12727
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Item Manganese and fluorine suppress bacterial blight on coffee seedlings grown in a nutrient solution(Editora UFLA, 2021) Velloso, Jeanny Alice; Pozza, Edson Ampelio; Pozza, Adelia Aziz Alexandre; Silva, Humberson Rocha; Pérez, Cristian David Plaza; Souza, José Otávio Gusmão deThe use of manganese (Mn) and fluorine (F) in the management of bacterial blight were evaluated in coffee seedlings grown in a nutrient solution. The experiment was carried out with the cultivar Catuaí Vermelho IAC 99. The treatments consisted of the combination of five doses of Mn with five of F, applied via leaf, using Mn sulfate and sodium fluoride, in a 5x5 factorial scheme. The plants were inoculated with bacterial suspension seven days after foliar application of F and Mn doses. The incidence and severity assessments were performed at an interval of 24 hours for 10 days. Photosynthetic activity was assessed using the infrared gas analyzer. Stomatal conductance, photosynthesis, transpiration, PAR radiation and internal CO2 were ana lyzed. The chlorophyll content was calculated indirectly. The leaf analysis was performed by digestion in HNO3 to determine the levels of Mn. Variables such as Area Under Incidence Disease Progress (AUIDP), Area Under Severity Disease Progress (AUSDP), chlorophyll a, b, and total concentrations and photosynthesis were submitted to the Shapiro-Wilk test. The treatment means were subjected to linear regression analysis. Data were analyzed using software R. There was a significant interaction (P <0.05) between the concentrations of Mn and F for the AUIDP and (AUSDP). Doses between 0.7 and 1.4 g L-1 of Mn combined with doses of 0.10 to 0.12 g L-1 of F were more effective in suppressing the bacterial blight, after analysis for both variables. The increase in Mn concentrations in leaves reduced liquid photosynthesis. The interaction between Mn and F suppressed the bacterial blight intensity of the coffee plants in nutrient solution.Item Determination of physical and chemical quality of coffee beans under improved potassium fertilization managements(Editora UFLA, 2021) Moreira, Diulie Talita; Mellis, Estêvão Vicari; Giomo, Gerson Silva; Teixeira, Luiz Antonio Junqueira; Cavalli, Edilson; Ramos, Lucas FerreiraCoffee quality is the key attribute for establishing its price and commercialization. As the classification of coffee quality is a complex process, mainly based on a subjective judgment, difficult to define and measure, a complementary approach to the current procedures involving physical and chemical methods would bring more effectiveness to the process of quality determination. The chemical composition of the coffee bean is influenced by several factors, among them the nutritional management of coffee trees and, the use of potassium chloride (KCl), which has intensified losses in bean quality due to excessive chlorine in its composition. The aim of this study was to evaluate the efficiency of sources and forms of K application in the quality of beans, and assessment of methodologies for determination of physical and chemical qualities of beans. The experiment was conducted with Yellow Ca tuaí cultivar, from 2017 to 2019, in a randomized experimental block design with five replicates. Six treatments were applied, containing proportions of KCl/K2SO4, as follows: T1-100% KCl; T2-75%/25%; T3-50%/50%; T4-25%/75%; T5-100% of K2SO4 and T6-100% of KCl + two foliar K2SO4 applications. The variables addressed in the study were sensory analysis, screen of beans, electrical conductivity (EC), potassium leaching (KL), titratable total acidity (TTA), and coffee bean color. It was verified that KL, EC, and other chromatic parameters were efficient in detecting alterations on coffee bean caused by the use of KC1. Total (T5) or partial (T4) replacement of KC1 by K2SO4 applied to soil improved chemical characteristics and color of coffee beans. Supplemental foliar fertilization with K2SO4 (T6) was efficient to minimize deleterious effects of KCl on quality of coffee beans, improving beverage quality and grain size, especially in high productive harvests.Item Nutritional efficiency in phosphorus of arabica coffee genotypes(Editora UFLA, 2021) Vilela, Diego Júnior Martins; Coelho, Larissa Sousa; Silva, Douglas Ramos Guelfi; Carvalho, Gladyston Rodrigues; Botelho, Cesar Elias; Ferreira, André DominghettiNutritional efficiency is a term used to characterize plants in their capacity to uptake and use nutrients, being related to the efficiency of uptake, translocation, and utilization of nutrients. Different coffee genotypes are expected to exhibit variability in their nutritional efficiency. This work aimed to evaluate the phosphorus nutritional efficiency in arabica coffee genotypes. The experiment was carried out in a greenhouse of the Empresa de Pesquisa Agropecuária de Minas Gerais (EPAMIG), located in the municipality of Lavras – Minas Gerais, Brazil. The experimental design was a randomized complete block design, in a 10x2 factorial scheme (10 arabica coffee genotypes and two dosages of phosphate fertilization), with four replicates. Each experimental plot consisted of one pot with ten liters of soil, with one plant. The cultivars Catiguá MG2, MGS Ametista and Sarchimor MG 8840 are neither efficient nor responsive to phosphate fertilization. Progeny H 6-47-10 pl. 3 and the cultivar Catuaí Vermelho IAC 144 are not efficient but are responsive to phosphate fertilization. The cultivars Paraíso MG H 419-1, Topázio MG 1190 and MGS Paraíso 2 are efficient but are not responsive to phosphate fertilization. The cultivars Bourbon Amarelo IAC J10 and MGS Aranãs are efficient and responsive to phosphate fertilization.