Coffee Science - v.14, n.1, 2019

URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/12058

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Applications of copper-based fungicides and infestations of Leucoptera coffeella (Guérin-Mèneville & Perrottet) in coffee plants
(Editora UFLA, 2019-01) Sabino, Paulo Henrique de Siqueira; Silva, Gian Otávio Alves da; Silva, Adriano Bortolotti da; Carvalho, Geraldo Andrade
The present study aimed to evaluate the effects of applying fungicides with different sources of copper and of the number of applications on the occurrence of Leucoptera coffeella (Guérin-Menéville & Perrottet, 1842) (Lepidoptera: Lyonetiidae) and on the wax content on leaves in a coffee plantation. Four applications of fungicides were carried out, and the effects on the number of leaves mined by the insect and on the wax content on the leaf surface were evaluated. The copper- based fungicides increased the number of leaves mined by the leaf-miner and reduced the wax content on the coffee leaf surfaces in both periods studied.
Infection process of Cercospora coffeicola in immature coffee fruits
(Editora UFLA, 2019-01) Paula, Paulo Victor Augusto Azevedo de; Pozza, Edson Ampélio; Alves, Eduardo; Moreira, Silvino Intra; Paula, Júlio Cesar Azevedo; Santos, Leandro Alvarenga
Cercosporiosis is caused by Cercospora coffeicola and represents a very important coffee plants phytosanitary problem. Catuaí IAC 144 and Topázio cultivars at the F2 stage were inoculated with a conidial suspension. Samples were collected at 4, 8, 12, 24, 36, 48, 72, 96, and 168 hours after inoculation (hai) for scanning electron microscope studies. Fungal germination in epidermal surface occurred four hai; penetration only through epidermal wounds, without appressoria, started at 12 hai while the mycelial colonization occurred at 72 hai. The infection in immature coffee fruits implies brown eyespot control management anticipation need, even before the first symptoms.
Nitrogen fertilizers technologies for coffee plants
(Editora UFLA, 2019-01) Chagas, Wantuir Filipe Teixeira; Silva, Douglas Ramos Guelfi; Lacerda, Jordana Reis; Pinto, Leandro Campos; Andrade, André Baldansi; Faquin, Valdemar
The application of urea in coffee crop has caused high losses of nitrogen (N) by volatilization, causing low use and recovery of this nutrient. This low use of N may interfere in the growth and nutrition of the coffee crop and thus, influence the efficiency of the nitrogen fertilization. The aim in this work was to assess the growth, nutritional and physiological characteristics and the agronomic efficiency of the nitrogen fertilization with different nitrogen fertilizer technologies. The experiment was performed in a greenhouse in pots with a volume of 14 L. In each pot, it was performed the transplanting of two plants of coffee. The experimental design was entirely randomized, with four replicates. The following nitrogen fertilizers were applied in the dose of 10g pot -1 , devided into three applications with interval of 50 days: Conventional urea; ammonium nitrate; urea + formaldehyde; Polyblen Extend ® ; Polyblen Montanha ® ; Urea + polyurethane; urea + plastic resin; ammonium sulfate + CaCO 3 and the control, without N application. After cropping, it was evaluated the growth, nutritional and physiological parameters. Afterward, it was calculated two agronomic efficiency index of the nitrogen fertilization. The highest values of plants height, the total dry mass of plants and leaf area in coffee seedlings were found with the application of Polyblen Extend ® . This blend also provided higher accumulation of N in the leaf and the whole plant. The application of Polyblen Extend ® provided higher agronomic efficiency and also enhanced the photosynthetic rate in the coffee plants.
Phialomyces macrosporus reduces Cercospora coffeicola survival on symptomatic coffee leaves
(Editora UFLA, 2019-01) Laborde, Marie Caroline Ferreira; Botelho, Deila Magna dos Santos; Rodríguez, Gabriel Alfonso Alvarez; Resende, Mário Lúcio Vilela de; Queiroz, Marisa Vieira de; Batista, Aline Duarte; Cardoso, Patrícia Gomes; Pascholati, Sérgio Florentino; Gusmão, Luis Fernando Pascholati; Martins, Samuel Júlio; Medeiros, Flávio Henrique Vasconcelos de
Brown eye spot is among the most important coffee diseases, it is caused by a necrotrophic fungal Cercospora coffeicola. Saprobe fungi have potential in reducing the survival of necrotrophic pathogens and can act through competition of nutrients, mycoparasitism, antibiosis and resistance induction. We have screened saprobe fungi for the ability to reduce C. coffeicola sporulation and viability and determined the possible mechanisms involved in the biocontrol. The selected saprobe fungus, Phialomyces macrosporus, reduced the germination of C. coffeicola conidia by 40%. P. macrosporus produced both volatile and non-volatile compounds that inhibited C. coffeicola growth, sporulation and viability. The production of antimicrobial substances was the main mode of action used by the saprobe fungi. Therefore, P. macrosporus is a promising biological agent for the integrated management of brown eye spot
Selection of coffee progenies with large beans resistant to rust and cercospora leaf spot
(Editora UFLA, 2019-01) Pereira, Fernanda Aparecida Castro; Carvalho, Samuel Pereira de; Viana, Mariana Thereza Rodrigues; Vidal, Douglas Alves; Ferreira, Guilherme Souza; Silva, Joyce Alves Goulart da; Sâmia, Michelly Pereira
Rust is the main disease of coffee. Recently, cercospora leaf spot has grown in importance, intensifying defoliation and decreasing grain yield in Coffea arabica. The Big Coffee VL is a variety of C. arabica, with large beans. There is still little information on this variety. Because of this, the aim of this study was to use a mixed model approach to select the best progenies of “Big Coffee VL” for resistance to rust and cercospora leaf spot. There were evaluated 12 progenies with high bean yields. Based on bean size, leaves and plant size, plants within each progeny were classified as “small” (P), “medium” (M) and “large” (G). The experimental design was in blocks completely randomized, with six replicates and one plant per plot. Six measurements were carried out every 15 days for each plant by selecting 20 fully exposed leaves with higher and lower sun exposures. The measurements summarized disease severity using two diagrammatic scales to obtain the area of the leaf under rust or Cercospora leaf spot. A mixed model approach was used to calculate genotypic value (GV) and heritability estimates. The Mulamba and Mock index was used to select the most resistant progenies, in which the sum of rankings was weighted by a heritability value. Five progenies were selected; three progenies were G (G17, G9, and G12), one progeny was M (M5) and another progeny P (P23). Among these, M5 and P23 progenies are the most productive and may have potential use in future studies. This work presents the potential in investigating the new C. arabica variety.
Simultaneous selection in coffee progenies of mundo novo by selection indices
(Editora UFLA, 2019-01) Tasson, Guilherme Augusto Teixeira; Nadaleti, Denis Henrique Silva; Carvalho, Gladyston Rodrigues; Pereira, Fernanda Aparecida Castro; Andrade, Vinícius Teixeira; Botelho, César Elias
Coffee cultivars that are better adapted and more productive can help reduce production costs and make coffee cultivation more profitable. The Mundo Novo cultivar has stood out as one of the most productive cultivars of Coffea arabica L. Therefore, the aim of this work was to select Mundo Novo progenies with high bean yield capacity and with other agronomic characteristics of interest. We evaluated the bean yield, seed size, plant height, upper and lower canopy diameter, stem diameter, and plant vigor of 24 F 4 progenies and one check cultivar. The experimental design consisted of a randomized complete block design with three replicates and experiments were carried out in two sites: São Sebastião do Paraíso (SSP) and Três Pontas (TP), MG, Brazil. The mixed model approach was used to calculate the genotypic value for each progeny, after which the selective accuracy and genetic gain of the two best progenies in each trait were calculated, the simultaneous selection index of Mulamba and Mock was used to select the two most promising progenies at each site. In general, the genetic gain was higher at SSP than at TP. In SSP, the most promising progenies were 1 [IAC376-2 (M. Novo) x IAC386-17 (M. Novo)] and 20 [IAC382-10 (M. Novo) x IAC388-20 (M. Novo)]. In TP, the most promising progeny was 22 [H1535/181 (M. Novo) x (S795) 1344/10/5], together with the check (Mundo Novo IAC379/19). The highest selection gain was expressed for bean size (the percentage of beans retained in sieve 17).
Sucrose in detoxification of coffee plants whit glyphosate drift
(Editora UFLA, 2019-01) Alecrim, Ademilson de Oliveira; Guimarães, Rubens José; Castanheira, Dalyse Toledo; Rezende, Tiago Teruel; Carvalho, Milene Alves de Figueiredo; Voltolini, Giovani Belutti
The weed control in coffee plants has great importance, as they compete for light, water and nutrients. The chemical control is the most used, emphasizing the glyphosate, however, when applied, drift can occur and consequently cause injuries to coffee. Many farmers use the sucrose application with the objective to reverse the damage caused by the herbicide drift, even without scientific basis to justify such action. The objective of this study was to evaluate the effect of the sucrose application on the detoxification of coffee plants in the implantation phase with glyphosate drift. The experiment was carried out in a greenhouse, using a randomized block design, arranged in a 3 x 3 factorial scheme with 2 additional treatments, using 3 sucrose doses (2, 4 and 8%) with 3 application times (1, 24 and 168 hours after intoxication with 10% of the commercial glyphosate dose) with an additional one in which the plants were not intoxicated and not treated with sucrose and another only with plants intoxicated by glyphosate. After 75 days performing the experiment, growth, physiological and anatomical characteristics were evaluated. The application of sucrose in the reversal of intoxication of growth variables (height, leaf area number of leaves, shoot dry weight and dry weight of the root system) was not efficient. The objective of this study was to evaluate the effect of the sucrose application on the detoxification of coffee plants in the implantation phase with glyphosate drift. For the physiological variables the application of 2% sucrose, one hour after glyphosate intoxication was the most efficient treatment.