14 documents found, page 1 of 2
Overcoming the challenge of bunch occlusion by leaves for vineyard yield estima...
Victorino, Gonçalo; Braga, Ricardo; Santos-Victor, José; Lopes, C.M.Accurate yield estimation is of utmost importance for the entire grape and wine production chain, yet it remains an extremely challenging process due to high spatial and temporal variability in vineyards. Recent research has focused on using image analysis for vineyard yield estimation, with one of the major obstacles being the high degree of occlusion of bunches by leaves. This work uses canopy features obtain...
Assessing the contribution of ECa and NDVI in the delineation of management zon...
Esteves, Catarina; Fangueiro, David; Braga, Ricardo; Martins, Miguel; Botelho, ManuelPrecision fertilization implies the need to identify the variability of soil fertility, which is costly and time-consuming. Remotely measured data can be a solution. Using this strategy, a study was conducted, in a vineyard, to delineate different management zones using two indicators: apparent soil electrical conductivity (ECa) and normalized difference vegetation index (NDVI). To understand the contribution o...
Remote Sensing (NDVI) and Apparent Soil Electrical Conductivity (ECap) to Delin...
Esteves, Catarina; Ribeiro, Henrique; Braga, Ricardo; Fangueiro, DavidThe intensification of agriculture has greatly enhanced crop productivity, but also its potential environmental impact. Nutrient recycling and an increase in resource use efficiency are the key points to keep production at high levels with minimum impact. The present work’s goal was to provide new insight on the spatial variability of soil chemical properties in a vineyard. For this, three different zones were ...
Estimation of daily reference evapotranspiration from NASA POWER reanalysis pro...
Rodrigues, Gonçalo C.; Braga, RicardoThis study aims at assessing the accuracy of estimating daily reference evapotranspiration (ETo) computed with NASA POWER reanalysis products. Daily ETo estimated from local observations of weather variables in 14 weather stations distributed across Alentejo Region, Southern Portugal were compared with ETo derived from NASA POWER weather data, using raw and biascorrected datasets. Three different methods were u...
Evaluation of NASA POWER reanalysis products to estimate daily weather variable...
Rodrigues, Gonçalo C.; Braga, RicardoThis study aims to evaluate NASA POWER reanalysis products for daily surface maximum (Tmax) and minimum (Tmin) temperatures, solar radiation (Rs), relative humidity (RH) and wind speed (Ws) when compared with observed data from 14 distributed weather stations across Alentejo Region, Southern Portugal, with a hot summer Mediterranean climate. Results showed that there is good agreement between NASA POWER reanaly...
A simple procedure to estimate reference evapotranspiration during the irrigati...
Rodrigues, Gonçalo C.; Braga, RicardoThe Food and Agricultural Organization of the United Nations (FAO) Penman–Monteith (PM) method is widely regarded as the most effective reference evapotranspiration (ETo) estimator; however, it requires a wide range of data that may be scarce in some rural regions. When feasible relative humidity, solar radiation and wind speed data are unavailable, a temperature-based method may be useful to estimate ETo and p...
Estimation of Reference Evapotranspiration during the Irrigation Season Using N...
Rodrigues, Gonçalo C.; Braga, RicardoThe FAO-56 Penman–Monteith (PM) equation is regarded as the most accurate equation to estimate reference evapotranspiration (ETo). However, it requires a broad range of data that may not be available or of reasonable quality. In this study, nine temperature-based methods were assessed for ETo estimation during the irrigation at fourteen locations distributed through a hot-summer Mediterranean climate region of ...
A Simple Application for Computing Reference Evapotranspiration with Various Le...
Rodrigues, Gonçalo C.; Braga, RicardoReference evapotranspiration (ETo) estimations may be used to improve the efficiency of irrigated agriculture. However, its computation can be complex and could require numerous weather data that are not always available for many locations. Different methods are available to estimate ETo when limited data are available, and the assessment of the most accurate one can be difficult and time consuming. There are s...
Yield components detection and image-based indicators for non-invasive grapevin...
Victorino, Gonçalo; Braga, Ricardo; Santos-Victor, José; Lopes, C.M.Forecasting vineyard yield with accuracy is one of the most important trends of research in viticulture today. Conventional methods for yield forecasting are manual, require a lot of labour and resources and are often destructive. Recently, image-analysis approaches have been explored to address this issue. Many of these approaches encompass cameras deployed on ground platforms that collect images in proximal r...
VINBOT - um robô terrestre para viticultura de precisão
Lopes, C.M.; Graça, João; Victorino, G.; Guzmán, Robert; Torres, Albert; Reyes, Miguel; Barriguinha, André; Braga, Ricardo; Monteiro, AnaNos últimos anos tem-se verificado um aumento exponencial da utilização de robôs na agricultura, estando a União Europeia a fomentar fortemente a investigação nesta área através da Agenda de Investigação Estratégica para a Robótica na Europa. A grande importância do conhecimento da variabilidade espacial do vigor e produção em Viticultura, tem levado ao desenvolvimento de ferramentas de Viticultura de Precisão ...