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URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
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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 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.