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URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
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Resultados da Pesquisa
Item Morphology of the coffee root system using polyethylene film(Universidade Federal de Viçosa, 2023-08-25) Nascimento, Letícia Gonçalves do; Assis, Gleice Aparecida de; Fernandes, Marco Iony dos Santos; Caixeta, Lucas Gomes; Carvalho, Fábio Janoni; Mazziero, Beatriz GallucciIn the initial phase of the coffee crop, the control of weeds and water availability for the establishment of the plants is a concern. The polyethylene cover can positively influence the chemical and biological characteristics of the soil and, consequently, the root system. The objective of this work was to evaluate the morphology of the root system of coffee plants using polyethylene mulching of different widths and colors. Coffee was planted in December 2016 using the cultivar Topázio MG-1190. A randomized repetitions design was used, with four blocks and five treatments, as follows: 1.20-m wide white/black mulching, 1.40-m white/black mulching, 1.20-m silver/black mulching, 1.40-m silver /black mulching, and no mulching. Total root dry matter per soil volume, total root length per soil volume, total root volume per soil volume, total root area per soil volume, specific root surface, specific root length, and mean root diameter were all evaluated. Roots with smaller diameters were concentrated in the 0-0.20 m depth layer, while in the 0.20-0.40 m depth layer, roots with larger diameters were found. Plants grown in 1.20-m silver/black mulching showed a greater surface area and a specific length of the roots.Item Multispectral images for discrimination of sources and doses of fertilizer in coffee plants(Universidade Federal de Viçosa, 2023-06-16) Rezende, Camila Isabel Pereira; Assis, Gleice Aparecida de; Martins, George Deroco; Carvalho, Fábio Janoni; Franco, Miguel Henrique Rosa; Araújo, Nathalia Oliveira deRemote monitoring of the management of coffee crops is necessary as the demand in decision-making, where the aim is to rise production based on sustainable management is in a constant growth. In this work, it was evaluated the potential of images obtained by low-cost sensors in the discrimination of sources and doses of mineral and organomineral fertilizers in coffee. The experimental design was in randomized blocks, with five blocks and six treatments, as follows: (T1) - 100% of the organomineral treatment; (T2) - 70% of the organomineral treatment; (T3) - 50% of the organomineral treatment; (T4) - 100% of mineral fertilization; (T5) - standard treatment of the farm and (T6) - 70% of mineral fertilization. After management, we used the Mapir 3 Survey3W camera coupled to an ARP drone – Phantom4 to take images of the experiment over a 12-month vegetative period. Combined with image taking, it was collected agronomic parameters of coffee growth and productivity for two crops and concluded that different fertilization doses did not significantly affect the analyzed parameters. Based on the supervised classification of multispectral images, it was possible to discriminate treatments with a higher degree of accuracy (86.66% accuracy) than when analyzing coffee growth parameters.Item Application technology for chemically controlling coffee leaf miner in the cerrado of Minas Gerais State(Universidade Federal Rural da Amazônia (UFRA), 2017) Zampiroli, Renan; Alvarenga, Cleyton Batista de; Andaló, Vanessa; Rinaldi, Paula Cristina; Assis, Gleice Aparecida deLeaf miner is a major coffee tree pest that causes severe losses. Most farmers perform chemical control in an attempt to reduce damage to the crop. Thus, the current study aims to analyze spraying efficiency and control effectiveness according to the management plan adopted in a coffee farm in the Cerrado of Minas Gerais. The application used Arbus sprayer, model 2,000, at the pressure of 600 kPa. The droplet spectrum was analyzed using water-sensitive paper. The plant architecture influence on the application quality was evaluated through the droplet spectrum and control efficacy. We conclude that the plant crown height and depth affected application efficiency. Spraying was an effective phytosanitary control of coffee leaf miner, reaching 87.5% control efficiency ratio, considering that infestation was three times higher than that recommended for the applied pesticide at the time of application.Item Association of Heterorhabditis amazonensis and Beauveria bassiana aiming the control of Hypothenemus hampei(Editora UFLA, 2020) Moreira, Igor Bitencourt Lima; Andaló, Vanessa; Assis, Gleice Aparecida de; Faria, Lucas Silva de; Carvalho, Fabio Janoni; Zampiroli, RenanAmong the main problems for coffee production, it is possible to mention the occurrence of coffee borer, Hypothenemus hampei. In order to seek alternatives to control the pest, the proposed objective was to evaluate the interaction between Beauveria bassiana UFU01 and Heterorhabditis amazonensis MC01 on the control of coffee borer. Therefore, four experiments were set. In the first, B. bassiana UFU01, H. amazonensis MC01 and both entomopathogens associated were applied in bored fruits displaced in vermiculite. In the second experiment, the methodology was similar to the previous one; however, the fruits were immersed in the suspensions. In the third experiment was evaluated the transport of B. bassiana UFU01 conidia by H. amazonensis, checking the mortality of Tenebrio molitor. In the fourth experiment, the fungus and the nematode were added to Petri dishes containing agar-water simultaneously to observe if the nematodes could carry B. bassiana UFU01 conidia. The obtained data were subjected to analysis of variance and the Tukey test (p <0.05), for comparison between means and regression analysis. It was found that, when entomopathogens were applied to vermiculite, treatments using B. bassiana UFU01 and H. amazonensis alone caused the highest mortality of H. hampei adults. For larvae, there was no difference among treatments. The same was observed when the fruits were dipped in the suspensions, with no difference among treatments. As for T. molitor mortality, it was observed that there was no difference among treatments. However, when applied in combination, there was a higher mortality caused by B. bassiana compared to H. amazonensis. In the last experiment, juveniles and conidia were found on the opposite side of the dish, and it can be inferred that the presence of conidia was due to transport by infective juveniles.Item Critical ranges for leaf nitrogen and potassium levels in coffee fertigated at the production phase(Universidade Federal do Ceará, 2015-01) Assis, Gleice Aparecida de; Guimarães, Rubens José; Colombo, Alberto; Scalco, Myriane Stella; Dominghetti, Anderson WilliamWith the aim of establishing critical ranges for the leaf nitrogen (N) and potassium (K) levels in fertigated coffee crops under production, an experiment was carried out in the experimental area of the Sector for Coffee Cultivation of the Department of Agriculture at the Federal University of Lavras, in Brazil. Treatments consisted of five levels of fertilizer applied through fertigation: 30%, 80%, 130%, 180% and 230% of the recommended amounts of N and K for rainfed coffee grown in Minas Gerais. A randomised block design with four replications was used. Critical ranges for nutrient concentrations in the leaves were established from the results of growth characteristics (plant height and stem diameter), leaf analyses and productivity. The results obtained were: a) nitrogen (g kg -1 ): 32.39 to 32.40 for January/February; 33.60 to 33.61 for March/April; 27.39 to 27.42 for May/June; 24.23 to 24.24 for July/August; 26.06 to 26.09 for September/October and 26.50 to 26.51 for November/December; b ) potassium (g kg -1 ): 20.08 to 20.14 for January/February; 17.89 to 17.91 for March/April; 15.93 to 15.96 for May/June; 15.29 to 15.35 for July/August; 16.61 to 16.64 for September/October and 20.58 to 20.64 for November/December.