Coffee Science_v.15, 2020
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/12726
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Resultados da Pesquisa
Item Use of foliar fertilizers as attenuators of injuries caused by glyphosate drift in young coffee plantations(Editora UFLA, 2020) Gonçalves, Ana Luisa Lucca; Pereira, Gustavo Antônio Mendes; Silva, Larissa Aparecida; Alves, Deivide Patrik; Pucci, Laís Franchini; Gonçalves, Victor Afonso Reis; Reis, Marcelo Rodrigues dosGlyphosate is the most used product for weed control in young coffee planting rows. The application is carried out in a directed way, avoiding the contact of the product with the crop. However, drift and consequent plant injuries frequently occur. An alternative to reduce these injuries is the use of attenuators capable of reducing the negative effects caused by this herbicide. Therefore, the objective of this study is to verify the efficiency of foliar fertilizers (Fertiactyl Pós® and Crop+) as attenuators of the toxic effects caused by the use of glyphosate in the coffee crop. Thus, coffee seedlings were subjected to different doses of the mixture of Fertiactyl Pós® with glyphosate and Crop+ with glyphosate. The treatments were applied on top of the plants. The percentage of coffee intoxication was evaluated at 14, 21, 28, 35, 42 and 90 days after application. At 90 days after application, height, leaf area and shoot and root dry matter were evaluated. Higher doses of glyphosate (1.44 and 2.88 kg ha-1) without the use of attenuators caused intoxication levels close to 80% at 28 and 90 DAA. The use of Fertiactyl Pós® and Crop+ reduced the injuries caused by the application of glyphosate, regardless of the dose of herbicide and fertilizers, but with different levels of action. All the morphological variables measured suffered a negative action with the isolated use of glyphosate, with a tendency to recover when the attenuators were applied. It is concluded that the two attenuators were efficient in suppressing the deleterious effects of glyphosate on coffee plants affected by this herbicide. For 0.720 kg ha-1 of glyphosate, the dose most used in the field, 8 L ha-1 is recommended for Fertiactyl Pós® and 4 L ha-1 for Crop+.Item Biochemical parameters of an Oxisol submitted to high doses of gypsum in the coffee culture(Editora UFLA, 2020) Naves, Andrêssa de Paula; Silva, Aline Oliveira; Barbosa, Marisângela Viana; Pinto, Flávio Araújo; Santos, Jessé Valentim dos; Saggin Junior, Orivaldo José; Guimarães, Paulo Tácito Gontijo; Carneiro, Marco Aurélio CarboneThe objective of this study was to determine the influence of increasing doses of agricultural gypsum on the quality of the soil biochemical parameters in coffee cultivation (Coffea arabica L.) over two climatic seasons in the Brazilian Cerrado. Soil samples were collected in two seasons (dry and rainy season), at 0.00 – 0.10 m depth of an Oxisol, submitted to doses 0 (GSA); 3.5 (G3.5); 7.0 (G7.0) and 14 (G14) t ha-1 of agricultural gypsum in the coffee planting line. The biochemical parameters evaluated were: total organic carbon (TOC); microbial biomass carbon (MBC); soil basal respiration (SBR); absolute enzymatic activities [Urease, acid phosphatase, hydrolysis of fluorescein diacetate (FDA)], and enzymatic activity per unit of MBC. The significant effect (p ≤ 0.05) of gypsum doses was observed for MBC and SBR, which were higher in the treatment with G7.0 application. TOC, the enzymatic activities of Phosphatase and the FDA showed no differences between treatments. On the other hand, the specific enzymatic activities by MBC were used to describe the differences between the doses of gypsum applied, generally with greater activity in treatments G7.0 and G14. The accumulated coffee productivity was higher in G14 treatment. The results presented confirmed that the biochemical parameters of the soil are key in the evaluation of changes in soil use, and that the increase in gypsum favors activity and microbial biomass.Item Classification, physicochemical, soil fertility, and relationship to Coffee robusta yield in soil map unit selected(Editora UFLA, 2020) Marbun, Posma; Nasution, Zulkifli; Hanum, Hamidah; Karim, AbubakarThe research was aimed to classify, characterize the physicochemical properties, determine the fertility of the soil, and to obtain the relationship of soil fertility on the character yield for Coffee robusta in the 10 units of the soil map (SMUs) selected. This research was conducted in Silima Pungga-Pungga sub-District, Dairi District, North Sumatra Province, Indonesia from July 2014 to June 2017. This research was conducted by overlay the maps, classifying soil profiles, characterizing soil, soil fertility assessing, and regression analysis of soil fertility with the yield for Coffee robusta using IBM SPSS Statistics v.20 software. The result showed the ten from 18 SMUs selected for Coffee robusta had the highest area in sequentially, namely SMU 11, 14, and 1. Based on the ten SMUs selected, found in two representative soil profiles, include the profile 1 (SMU 1, 2, 8, 9, 11, 13, 14, 16, 18) covering an area of 1,703.30 ha with the inceptisol and profile 10 (SMU 10) covering an area of 176.81 ha with the entisol. Inceptisol has greater thesoil physicochemical properties compared to entisol from ten SMUs selected for Coffee robusta. The effect of cation exchange capacity, base saturation, P-total, K-total, and C-organic have significantly increased the productivity of Coffee robusta by 89.30%. However, the effect was not significant to the 100 grains of dry weight.Item Using unmanned aerial vehicle and machine learning algorithm to monitor leaf nitrogen in coffee(Editora UFLA, 2020) Parreiras, Taya Cristo; Lense, Guilherme Henrique Expedito; Moreira, Rodrigo Santos; Santana, Derielsen Brandão; Mincato, Ronaldo LuizNitrogen is an essential element for coffee production. However, when fertilization do not consider the spatial variability of the agricultural parameters, it can generate economic losses, and environmental impacts. Thus, the monitoring of nitrogen is essential to the fertilizing management, and remote sensing based on unmanned aerial vehicles imagery has been evaluated for this task. This work aimed to analyze the potential of vegetation indices of the visible range, obtained with such vehicles, to monitor the nitrogen content of coffee plants in southern Minas Gerais, Brazil. Therefore, we performed leaf analysis using the Kjeldahl method, and we processed the images to produce the vegetation indices using Geographic Information Systems and photogrammetry software. Moreover, the images were classified using the Color Index of Vegetation and the Maximum Likelihood Classifier. As estimator tool, we created Random Forest models of classification and regression. We also evaluated the Pearson correlation coefficient between the nitrogen and the vegetation indices, and we performed the analysis of variance and the Tukey-Kramer test to assess whether there is a significant difference between the averages of these indices in relation to nitrogen levels. However, the models were not able to predict the nitrogen. The regression model obtained a R2 = 0.01. The classification model achieved an overall accuracy of 0.33 (33%), but it did not distinguish between the different levels of nitrogen. The correlation tests revealed that the vegetation indices are not correlated with the nitrogen, since the best index was the Green Leaf Index (R = 0.21). However, the image classification achieved a Kappa coefficient of 0.92, indicating that the tested index is efficient. Therefore, visible indices were not able to monitor the nitrogen in this case, but they should continue to be explored, since they could represent a less expensive alternative.Item Spatial correlation between the chlorophyll index and foliar npk levels in coffee crop(Editora UFLA, 2020) Zanella, Marco Antonio; Rodrigues Junior, Francelino Augusto; Sousa, Emanoel Di Tarso dos Santos; Martins, Rodrigo Nogueira; Calijuri, Maria LúciaDetection of spatial variability of data that can improve crop management is a key factor for precision agriculture. In agriculture, there is a need for tools to assist farmers in decision-making about proper nutrient management, aiming to achieve their full productive potential. Based on that, this study aimed to (1) determine the spatial correlations between the chlorophyll index (CI) and the foliar levels of nitrogen, phosphorus and potassium (NPK) in the coffee crop using geostatistical tools; and (2) to evaluate the potential use of this index as a tool for site-specific nutrient management in an irrigated coffee field. For that, a study was carried out in a 2.1 ha area under arabica coffee cultivation in Paula Cândido, Minas Gerais State, Brazil. Samplings of the CI were performed in 1141 plants using a portable chlorophyll meter (SPAD-502). Regarding the NPK analysis, leaf samples from one of each 10 plants used to measure the CI were taken for chemical analysis (114 plants). Then, the data were submitted to descriptive and geostatistical analysis. For the spatial correlation analysis, the Moran Bivariate Global (I) and the Local index (Ixy) were used. The results showed a moderate correlation between the CI and N (0.500), showing the potential of the chlorophyll meter as a tool for site-specific nitrogen management in the coffee crop. Differently, the CI is not recommended for P and K management since they were not well correlated. Lastly, as a tool that performs indirect measurements, the results from the chlorophyll meter should be validated by field measurements to local calibrations.Item Soil chemical attributes in coffee growing with different agronomic techniques(Editora UFLA, 2020) Voltolini, Giovani Belutti; Silva, Larissa Cocato da; Alecrim, Ademilson de Oliveira; Castanheira, Dalyse Toledo; Resende, Laís Sousa; Rezende, Tiago Teruel; Guimarães, Rubens JoséThe objective was to evaluate the chemical attributes in a coffee growing area, according to different agronomic techniques used and their associations. The experiment was conducted in the field, from January 2016 to October 2018. Coffee was planted in January 2016, with Mundo Novo IAC 379-19 coffee seedlings, with a spacing of 3.6 m between rows and 0.75 m between plants in the planting row. The factors under study were arranged in a 3x2x5 factorial scheme, making a total of 30 treatments. In the plots, three soil managements were randomized (soil cover with polyethylene film, soil cover with brachiaria-grass and conventional management of spontaneous vegetation). In the subplots, two types of fertilizers (conventional and increased-efficiency fertilizer). In the sub-subplots, four soil conditioners (coffee husk, phosphogypsum, water retention polymer, organic compost), and the control without conditioner. Aimed to evaluate soil chemical attributes in coffee growing with different agronomic techniques through the evaluation of: soil pH, phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), aluminum saturation (m) and base saturation (V%). The use of fertilizers combined with the application of organic compost or coffee husk, provide increased soil pH, as well as the use of ecological management of brachiaria-grass. The use of organic compost as a soil conditioner increases phosphorus availability in the soil. Coffee husk, as a soil conditioner, is an efficient potassium source for the coffee crop. The use of organic compost and phosphogypsum increases the calcium and magnesium contents in the soil. The use of organic compost and coffee husk was efficient in increasing the base saturation grown with coffee. The use of organic compost, coffee husk and phosphogypsum reduced aluminum saturation in the soil. Treatments associated with the use of organic compost improve calcium, phosphorus and magnesium levels, increase pH and base saturation, besides decreasing aluminum saturation.Item Screening for phosphate-solubilizing fungi from colombian andisols cultivated with coffee (Coffea arabica L.)(Editora UFLA, 2020) González-Osorio, Hernán; Botero, Carmenza E. Góngora; Rivera, Rubén Darío Medina; Vega, Nelson Wálter OsorioPhosphate (P) bioavailability is severely constrained in volcanic ash soils due to its high fixation rate. To overcome this problem the use of P-solubilizing fungi (PSF) has been proposed gaining recently great attention. To provide a better understanding of the dynamics of PSF in soils and to establish criteria for screening effective PSF a series of studies were conducted. PSF were isolated from coffee plantations grown in a Typic Udivitrand (QU), a Pachic Fulvundand (CH), and a Typic Melanudand (Ti). Fifty-five isolates (28 from CH, 19 from Ti, and 8 from QU) produced index of P solubilization among 16 and 106 10-6 kg dm-3 using as P source phosphate rock. The results suggest that the microbial P solubilization was not only associated to the decrease in the culture medium pH, but also the production of organic acids is associated with the most effective PSF. The higher production of organic acids seems to be associated with a lower fungal colony growth rate likely due to a carbon/energy drainage. The soil P-fixation capacity, soil organic content and degree of humification seems to control the relative abundance of PSF in the soils tested. In soils cultivated with coffee Phlebia gender is reported, for the first time, as a PSF.