Automatic grape bunch detection in vineyards based on affordable 3D phenotyping using a consumer webcam.

This work presents a methodology for 3-D phenotyping of vineyards based on images captured by a low cost high-definition webcamera. A novel software application integrated visual odometry and multiple-view stereo components to create dense and accurate three-dimensional points clouds for vines, properly transformed to millimeter scale. Geometrical and color features of the points were employed by a classification procedure that reached 93% of accuracy on detecting points belonging to grapes. Individual bunches were automatically delimited and their volumes estimated. The sum of the estimated volumes per vine presented a coefficient of correlation of R = 0.99 to the real grape weight observed in each vine after harvesting.SBIAgro 2017

Desertification climatic susceptibility to the Center-North region of Brazilian Semi-Arid.

Desertification process is a phenomenon of high environmental and social complexity because it embraces a significant number of indicators and variables that inter relate and that complement the comprehension of this process. One of the most useful and applied ways of the study of desertification verification is through the calculation o f the Aridity Index ( A I ). This way, this present study uses that methodol ogy to verify the situation of AI in Center - North region of Brazilian Semi - Arid. The aim was to investigate the variety of AI and its classifications during the period between 1961 and 2015, using temporal series of 30 years, expressed in the time interval of 2005, 2010 and 2015. It was possible to observe that therefore some changes in AI in many locations, where quantitative changes happened in the area, increasing mainly to the conditions of aridity aggravation, there was not the meaningful occurrence of alteration in the Desertification Tendency classification

Diferentes métodos de sensoriamento proximal do dossel de videiras promovem divergências no mapeamento de índices de vegetação.

A estimativa de índices de vegetação (IV) viabiliza o monitoramento da variabilidade espacial do vigor vegetativo em vinhedos, porém faz-se necessário questionar se diferentes práticas de sensoriamento podem interferir nos resultados obtidos. Este estudo demonstra a discrepância no mapeamento dos IV NDRE e NDVI estimados a partir de duas metodologias de coleta de dados de reflectância (ρ) do dossel de videiras, obtidos via sensoriamento proximal. Medidas georreferenciadas de ρ correspondentes aos comprimentos de onda (λ) de 670, 730 e 780 nm foram tomadas conforme duas disposições distintas do sensor ativo ACS-430 em relação a copa das plantas. Após a estimativa dos IV a sua predição espacial foi realizada por análise geoestatística e krigagem ordinária. Os valores interpolados foram normalizados e classificados para delimitação de zonas homogêneas (ZH) do vigor vegetativo no vinhedo avaliado. Determinou-se a variabilidade relativa quanto à estimativa dos IV por cada metodologia a partir do cálculo e da predição espacial do coeficiente de variação (CV). A comparação entre as regionalizações de ambos os IV foi realizada por medidas estatísticas de concordância entre os métodos de coleta de dados. Ambos os procedimentos de medida de ρ produziram estimativas dos IV com uma reduzida dispersão relativa em torno da média. Entretanto, a disposição espacial das ZH do NDRE e NDVI correspondentes a cada metodologia apresenta discrepâncias, dada a concordância ?moderada? e ?fraca? entre si, respectivamente

Calibration of chlorophyll hand-held meter based on vineyard NDVI zones for estimation of leaf N content.

The monitoring of chlorophyll content in grapevine leaves allows us to evaluate their N status, assisting with the information for the decision make about nutrient rate and application time to the vineyard. The present work aimed to propose an easy-to-use procedure for the calibration of a chlorophyll hand-held meter based on the NDVI homogeneous zones in a vineyard for the device readings and leaf sampling. We evaluated the wine grape ?Chardonnay? growing under drip irrigation in a vineyard located in the Southeast region of Brazil. Readings of the relative chlorophyll indices (a, b, and total) were taken in situ four times throughout the 2019 growing season, with the device placed on two leaves of every 40 pre-selected target plants in two homogeneous zones of NDVI previously defined in the vineyard. Subsequently, the chlorophyll and leaf nitrogen contents were determined in laboratory to relate them to the chlorophyll meter readings through generalized estimation equations. The chlorophyll meter is capable of estimating the levels of chlorophyll a, b and total by the models generated with an error of 0.98, 0.58, and 1.47 µg ml-1 cm-2 for calibration and of 1.03, 0.67, and 1.49 µg ml-1 cm-2 for prediction, respectively. The functions developed for the leaf N content present calibration error of 1.49 g kg-1 and prediction error of 3.39 g kg-1, but capable of providing an estimate when error is less than the amplitude of nitrogen sufficiency