Biblioteca do Café
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Resultados da Pesquisa
Item Temporal analysis of Phoma leaf spot of coffee plants at different altitudes(Universidade Federal de Viçosa, 2025-04-25) Silva, Humberson Rocha; Pozza, Edson Ampélio; Freitas, Aurivan Soares de; Freitas, Marcelo Loran de Oliveira; Barbosa Junior, Mauro Peraro; Cirillo, Marcelo AngeloPhoma leaf spot (Phoma spp.) of coffee causes losses of between 15 and 43%, and presents significant variability over time and space, especially in mountain coffee production. Thus, the objective of this study was to evaluate the behavior of this disease at different altitudes and to use time series techniques and regression models to explain disease behavior. The experiment was conducted over two years (from September 2013 to August 2015) with monthly evaluations in a Coffea arabica L. plantation. The incidence and severity progress curves showed irregular behavior most of the time, typical of the disease. Higher altitudes provided higher disease incidence and severity values. Only the incidence and severity progress curves at the altitude of 1143.2 m showed significant autocorrelation over time. Thus, the first-order autocorrelation structure, AR(1), was incorporated in the estimates of the parameters of the linear and nonlinear models. Only the months from February to June/July 2014 were considered, when the disease progressed regularly. The rates obtained for the incidence, overall mean of the 85 points and mean altitude of 1143.2 m, were 5.2 and 4.6%, respectively, while the estimated rates for the severity data under the same conditions were 0.3 and 0.1%, respectively. These values represent the expected increase in incidence and severity each month. The Phoma leaf spot presents complex temporal dynamics, influenced by microclimatic variables associated with altitude.Item Effect of temperature and photoperiod on Pseudomonas syringae pv. garcae inoculum production(Editora UFLA, 2024-11-12) Oliveira, Júlia Marques; Pozza, Edson Ampélio; Belan, Leônidas Leoni; Freitas, Marcelo Loran de Oliveira; Tedardi, Vitória MorenoBacterial halo blight (BHB), whose etiological agent is the bacterium Pseudomonas syringae pv. garcae, is one of the main diseases occurring in coffee (Coffea arabica L.) leading to losses in nurseries and fields. This study aimed to assess the effect of five temperatures (20, 25, 30, 35, and 40 °C) and three photoperiods (continuous light, 12-hour light/dark, continuous dark) on the P. syringae pv. garcae inoculum concentration and the BHB progression re sulted from this inoculum, in coffee seedlings. Using a factorial design (5 x 3) with four replicates, Petri dishes inoculated with P. syringae pv. garcae were incubated for 48 hours, and the concentrations and bacterial cell dimensions were measured. The resulting inoculum was then used to inoculate coffee seedlings at 23 ± 2 °C in one leaf pair by wounding inoculation using a multi-needle apparatus. The disease severity was assessed, and the area under the disease progress curve (AUDPC) was calculated. Significant interaction (p < 0.05) between temperature and photoperiod was observed for inoculum concentration and cell dimensions. The highest inoculum concentration (2.2 x 10⁹ CFU/ml) was recorded at 25 °C under continuous light. The largest bacterial cells (4.4 µm in length and 0.7 µm in width) resulted from temperatures of 30 °C with 12-hour light/dark. For the AUDPC of BHB, a difference (p < 0.05) was observed only between inoculum production temperatures. The highest AUDPC was recorded at 25 °C, with a gradual decline observed as the temperature increased.Item Proposed diagrammatic scale to assess heat injury in coffee seedling canopy(Editora da Universidade Estadual de Maringá - EDUEM, 2023-04-28) Resende, Laís Sousa; Pozza, Edson Ampélio; Pereira, Renata Cristina Martins; Botrel, Élberis Pereira; Roteli, Karolaine de Cássia; Oliveira, Júlia MarquesA diagrammatic scale with five levels (0, 0.1 - 2.0, 2.0 - 6.0, 6.0 - 10, and 10 - 14) was developed and evaluated to measure the symptoms of heat injury in a coffee seedling canopy. The scale was constructed to increase assessment efficiency and align the estimations more closely with the actual values. Two assessments with the diagrammatic scale and one without were conducted with an interval of seven days. The evaluators using the proposed scale presented estimates with better levels of precision, accuracy, reproducibility, and repeatability than those using a conventional method. The proposed diagrammatic scale was shown to provide a reliable estimate for assessing the symptoms of heat injury on the canopy of in Coffea arabica L. seedlings. Therefore, it is possible to standardize heat injury evaluation methods using this diagrammatic scale, allowing for data comparisons with different cultivars.Item Coffee plant diseases affected by nutritional balance(Universidade Federal de Lavras, 2023-05-02) Pozza, Edson Ampélio; Pozza, Adélia Aziz AlexandreIn recent years, sustainability has become a priority in agricultural production programs throughout Brazilian territory due to the need to ensure food security and environmental quality. Diseases continue to be a factor limiting sustainable agricultural production, due to the great need for chemical defenses for their control. Thus, it is indispensable to make use of alternative management techniques to reduce the use of such chemical defenses and to increase resistance of plants to diseases. It is known that mineral nutrients affect plant resistance to diseases, and effective physical and biochemical response of plants to pathogens is determined by adequate concentrations of mineral elements in the plant tissues. This review presents the most recent information related to the mode of action of the nutrients in the host-pathogen interaction and individual action in the control of plant diseases with the use of essential nutrients, as well as other elements considered beneficial, such as Si. It also reports on the use of some of these mineral nutrients in control of the main diseases of the coffee plant that occur in Brazil, especially rust, cercosporiosis or brown eye spot, phoma leaf spot, and bacterial blight. In addition, contradictory and satisfactory results are found in the literature on the use of mineral nutrients in control of different diseases, including coffee diseases.Item Brown eye spot incidence during the vegetative stage of coffee grown in soil under sustainable management(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2022-08-29) Resende, Laís Sousa; Pozza, Edson Ampélio; Luz, André Luís Faustino; Souza, Paulo Estevão de; Vilela, Marina Scalioni; Castanheira, Dalyse Toledo; Guimarães, Rubens JoséThe objective of this work was to evaluate the influence of different soil coverings, fertilizer types, and soil conditioners on the incidence and severity of brown eye spot (Cercospora coffeicola) in coffee (Coffea arabica) during the vegetative stage. The experiment was carried out in a randomized complete block design, in a 3×2×5 factorial arrangement (soil coverings × fertilizer types × soil conditioners) in subdivided plots, with three replicates. Comparisons were made among: three soil covering (plastic film, Urochloa decumbens, and no covering) in the plots; two fertililizer types (conventional and controlled release) in the sub-plots; and four soil conditioners (coffee husk, agricultural gypsum, water retention polymer, and organic compound), as well as the control, in the sub-sub-plots. The area under the progress curve for disease incidence and severity showed the lowest mean without soil covering, whereas that for number of leaves was greater with the use of the controlled-release fertilizer. The plastic film provided a greater soil moisture and a lower soil resistance penetration. The chemical composition of the organic compound reduced coffee plants growth. Soil covering with plastic film or U. decumbens favors the high incidence of brown eye spot; however, it provides a greater soil moisture and, therefore, improves the growth of coffee plants in the vegetative stage.