Engenharia Agrícola
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/10363
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Item Comparing a single-sensor camera with a multisensor camera for monitoring coffee crop using unmanned aerial vehicles(Associação Brasileira de Engenharia Agrícola, 2021) Gomes, Amanda P. A.; Queiroz, Daniel M. de; Valente, Domingos S. M.; Pinto, Francisco de A. de C.; Rosas, Jorge T. F.There exist two options for digital cameras that can capture the near-infrared (NIR) band. Conventional red–green–blue (RGB, visible bands) cameras with a single sensor provide NIR band visibility based on the removal of the internal NIR-blocking filter. Alternatively, multisensor cameras exist that have a specific sensor for each band. The modified RGB cameras are of a lower price. In this context, the objective of this study was to compare the performance of a modified RGB camera with that of a multisensor camera for obtaining the normalized difference vegetation index (NDVI) in an area with coffee cultivations. A multispectral camera with five sensors and another camera with only one sensor were used. The NDVI of the coffee field was also measured using the GreenSeeker handheld NDVI sensor manufactured by Trimble. The images were calibrated radiometrically based on the targets in shades of gray made of napa, and the NDVI was calculated after image calibration. The calibration curves showed a high coefficient of determination. The NDVI value obtained with the calibrated images from the cameras showed a significant correlation with the values obtained by the GreenSeeker NDVI sensor, making it possible to obtain the variability pattern of the vegetation index. However, the NDVI obtained using the multisensor camera was closer to the NDVI obtained by the GreenSeeker NDVI sensor.Item Desempenho de derriçadora portátil de frutos do cafeeiro(Associação Brasileira de Engenharia Agrícola, 2005-09) Souza, Cristiano M. A. de; Queiroz, Daniel M. de; Pinto, Francisco de A. de C.; Teixeira, Mauri M.Este trabalho avaliou o desempenho de uma derriçadora portátil para cafeicultura de montanha durante a colheita de frutos de cafeeiros Catucaí e Catuaí, em vários estádios de desenvolvimento. Foram determinados as características dos cafeeiros, as curvas características do motor da derriçadora, a capacidade e a eficiência de derriça, o consumo de energia, a desfolha e o nível de ruído emitido pela máquina. A derriçadora portátil teve desempenho satisfatório por apresentar baixa desfolha e número de galhos quebrados, capacidade de derriça regular, baixo consumo específico de energia e elevada eficiência de derriça. O nível de ruído aumentou com o aumento da potência requerida na derriça.Item Spatial variability of apparent electrical conductivity and soil properties in a coffee production field(Associação Brasileira de Engenharia Agrícola, 2014-11) Valente, Domingos S. M.; Queiroz, Daniel M. de; Pinto, Francisco de A. de C.; Santos, Fábio L.; Santos, Nerilson T.Precision agriculture based on the physical and chemical properties of soil requires dense sampling to determine the spatial variability of these properties. This dense sampling is often expensive and time-consuming. One technique used to reduce sample numbers involves defining management zones based on information collected in the field. Some researchers have demonstrated the importance of soil electrical variables in defining management zones. The objective of this study was to evaluate the relationship between the spatial variability of the apparent electrical conductivity and the soil properties in the coffee production of mountain regions. Spatial variability maps were generated using a geostatistical method. Based on the spatial variability results, a correlation analysis, using bivariate Moran’s index, was done to evaluate the relationship between the apparent electrical conductivity and soil properties. The maps of potassium (K) and remaining phosphorus (P-rem) were the closest to the spatial variability pattern of the apparent electrical conductivity.