Leandro Rodrigues

Mr. Leandro Rodrigues

Faculty of Sciences, University of Porto, Porto, Portugal
orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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4 February 2023 in Agronomy
Verified
Journal Article
Open access
PDF file
Leandro RodriguesLeandro Rodrigues
Leandro Rodrigues
Sandro MagalhãesSandro Magalhães
Sandro Magalhães
Daniel Queirós da SilvaDaniel Queirós da Silva
Daniel Queirós da Silva
Filipe Neves dos SantosFilipe Neves dos Santos
Filipe Neves dos Santos
Mario CunhaMario Cunha
Mario Cunha
The efficiency of agricultural practices depends on the timing of their execution. Environmental conditions, such as rainfall, and crop-related traits, such as plant phenology, determine the success of practices such as irrigation. Moreover, plant phenology, the seasonal timing of biological events (e.g., cotyledon emergence), is strongly influenced by genetic, environmental, and management conditions. Therefore, assessing the timing the of crops’ phenological events and their spatiotemporal variability can improve decision making, allowing the thorough planning and timely execution of agricultural operations. Conventional techniques for crop phenology monitoring, such as field observations, can be prone to error, labour-intensive, and inefficient, particularly for crops with rapid growth and not very defined phenophases, such as vegetable crops. Thus, developing an accurate phenology monitoring system for vegetable crops is an important step towards sustainable practices. This paper evaluates the ability of computer vision (CV) techniques coupled with deep learning (DL) (CV_DL) as tools for the dynamic phenological classification of multiple vegetable crops at the subfield level, i.e., within the plot. Three DL models from the Single Shot Multibox Detector (SSD) architecture (SSD Inception v2, SSD MobileNet v2, and SSD ResNet 50) and one from You Only Look Once (YOLO) architecture (YOLO v4) were benchmarked through a custom dataset containing images of eight vegetable crops between emergence and harvest. The proposed benchmark includes the individual pairing of each model with the images of each crop. On average, YOLO v4 performed better than the SSD models, reaching an F1-Score of 85.5%, a mean average precision of 79.9%, and a balanced accuracy of 87.0%. In addition, YOLO v4 was tested with all available data approaching a real mixed cropping system. Hence, the same model can classify multiple vegetable crops across the growing season, allowing the accurate mapping of phenological dynamics. This study is the first to evaluate the potential of CV_DL for vegetable crops’ phenological research, a pivotal step towards automating decision support systems for precision horticulture.

29 March 2023 in IEEE Sensors Journal
Verified
Journal Article
Open access
Sandro MagalhãesSandro Magalhães
Sandro Magalhães
LCLuís Castro
Luís Castro
Leandro RodriguesLeandro Rodrigues
Leandro Rodrigues
TPTiago Cerveira Padilha
Tiago Cerveira Padilha
FCFrederico de Carvalho
Frederico de Carvalho
Antonio Paulo MoreiraAntonio Paulo Moreira
Antonio Paulo Moreira
Several thousand grapevine varieties exist, with even more naming identifiers. Adequate specialised labour is not available for proper classification or identification of grapevines, making the value of commercial vines uncertain. Traditional methods such as genetic analysis or ampelometry are time-consuming, expensive and often require expert skills that are even rarer. New vision-based systems benefit from advanced and innovative technology and can be used by non-experts in ampelometry. To this end, Deep Learning (DL) and Machine Learning (ML) approaches have been successfully applied for classification purposes. The present work extends the state-of-the-art by applying digital ampelometry techniques to larger grapevine varieties. We benchmarked MobileNet v2, ResNet-34 and VGG-11-BN DL classifiers to assess their ability for digital ampelography. In our experiment, all the models could identify the vines’ varieties through the leaf with a weighted F1 score higher than 92 %.

20 September 2021
Verified
Conference Paper
Closed access
FTFrancisco Terra
Francisco Terra
Leandro RodriguesLeandro Rodrigues
Leandro Rodrigues
Sandro MagalhãesSandro Magalhães
Sandro Magalhães
Filipe Neves dos SantosFilipe Neves dos Santos
Filipe Neves dos Santos
PMPedro Moura
Pedro Moura
Mario CunhaMario Cunha
Mario Cunha
The world society needs to produce more food with the highest quality standards to feed the world population with the same level of nutrition. Microfarms and local food production enable growing vegetables near the population and reducing the operational logistics costs related to post-harvest food handling. However, it isn’t economical viable neither efficient to have one person devoted to these microfarms task. To overcome this issue, we propose an open-source robotic solution capable of performing multitasks in small polyculture farms. This robot is equipped with optical sensors, manipulators and other mechatronic technology to monitor and process both biotic and abiotic agronomic data. This information supports the consequent activation of manipulators that perform several agricultural tasks: crop and weed detection, sowing and watering. The development of the robot meets low-cost requirements so that it can be a putative commercial solution. This solution is designed to be relevant as a test platform to support the assembly of new sensors and further develop new cognitive solutions, to raise awareness on topics related to Precision Agriculture. We are looking for a rational use of resources and several other aspects of an evolved, economically efficient and ecologically sustainable agriculture.

18 August 2024 in Horticulturae
Verified
Journal Article
Open access
PDF file
RTRenan Tosin
Renan Tosin
IPIgor Portis
Igor Portis
Leandro RodriguesLeandro Rodrigues
Leandro Rodrigues
IGIgor Gonçalves
Igor Gonçalves
CBCatarina da Costa Rodrigues Barbosa
Catarina da Costa Rodrigues Barbosa
Mario CunhaMario Cunha
Mario Cunha
This study investigates how grapevines (Vitis vinifera L.) respond to shading induced by artificial nets, focusing on physiological and metabolic changes. Through a multidisciplinary approach, grapevines’ adaptations to shading are presented via biochemical analyses and hyperspectral data that are then combined with systems biology techniques. In the study, conducted in a ‘Moscatel Galego Branco’ vineyard in Portugal’s Douro Wine Region during post-veraison, shading was applied and predawn leaf water potential (Ψpd) was then measured to assess water stress. Biochemical analyses and hyperspectral data were integrated to explore adaptations to shading, revealing higher chlorophyll levels (chlorophyll a-b 117.39% higher) and increased Reactive Oxygen Species (ROS) levels in unshaded vines (52.10% higher). Using a self-learning artificial intelligence algorithm (SL-AI), simulations highlighted ROS’s role in stress response and accurately predicted chlorophyll a (R2: 0.92, MAPE: 24.39%), chlorophyll b (R2: 0.96, MAPE: 17.61%), and ROS levels (R2: 0.76, MAPE: 52.17%). In silico simulations employing flux balance analysis (FBA) elucidated distinct metabolic phenotypes between shaded and unshaded vines across cellular compartments. Integrating these findings provides a systems biology approach for understanding grapevine responses to environmental stressors. The leveraging of advanced omics technologies and precise metabolic models holds immense potential for untangling grapevine metabolism and optimizing viticultural practices for enhanced productivity and quality.

15 November 2023 in Biology and Life Sciences Forum
Verified
Conference Paper
Open access
PDF file
Leandro RodriguesLeandro Rodrigues
Leandro Rodrigues
PMPedro Moura
Pedro Moura
FTFrancisco Terra
Francisco Terra
ACAlexandre Magno Carvalho
Alexandre Magno Carvalho
JSJosé Sarmento
José Sarmento
Mario CunhaMario Cunha
Mario Cunha
Plant-soil sensing devices coupled with Artificial Intelligence autonomously collect and process in situ plant phenotypic data. A challenge of this approach is the limited incorporation of phenotype data into decision support systems designed to harness agricultural practices and forecast plant behavior within the intricate context of genotype, environment, and management interactions (G × E × M). To enhance the role of digital phenotyping in supporting Precision Agriculture, this paper proposes a sensing network based on the Internet of Things. The developed system comprises three modules: data collection, communication, and a cloud server. Several processes co-occur in the server, namely data visualization to confirm the correct sensors and data stream functioning. In addition, a crop growth model (CGM) runs on the server, which is powered by the collected data. The simulations generated by the model will support agricultural decisions, obtaining, in advance, insights about plant behavior considering several G × E × M scenarios. To assess the performance of the proposed network to provide reliable data to the model, a greenhouse was equipped with several sensors that collect plant, environment, and soil data (e.g., leaf numbers, air temperature, soil moisture). The proposed network can provide real-time causal support for advanced agricultural practices, evolving from a data-driven approach to an integrative framework where context (G × E × M) drives decision making.

8 November 2023 in Biology and Life Sciences Forum
Verified
Conference Paper
Open access
PDF file
MSMaria Santos-Campos
Maria Santos-Campos
RTRenan Tosin
Renan Tosin
Leandro RodriguesLeandro Rodrigues
Leandro Rodrigues
IGIgor Gonçalves
Igor Gonçalves
CBCatarina da Costa Rodrigues Barbosa
Catarina da Costa Rodrigues Barbosa
Mario CunhaMario Cunha
Mario Cunha
Sustainable and efficient agricultural production is a growing priority in modern society. Viticulture, an important agricultural and food sector, also faces this challenge. Precision Viticulture (PV) has gained prominence as it aims to foster high-quality, efficient, and environmentally sustainable practices. The Soluble Solids Content (SSC) is essential for assessing grape ripeness and quality in the winemaking process. Conventional methods for determining SSC values (expressed in °Brix) are invasive, expensive, and labour-intensive, necessitating sample preparation, making large-scale analysis impractical. In response to these limitations, this study presents an innovative approach within the field of Precision Viticulture. It focuses on the non-invasive prediction of SSC using low-cost proximal hyperspectral optical sensors. These sensors rely on spectral reflectance measurements in the range of 340–850 nm. This study was conducted in a commercial vineyard in the Demarcated Douro Region, Cima-Corgo sub-region, Portugal, over six weeks during ripening. In total, 169 grape berries from Touriga Nacional vines were analysed under three irrigation regimes (no irrigation, 30% ETc, and 60% ETc). After organising and preprocessing the data, machine learning algorithms, namely Partial Least Squares Regression (PLS), Random Forest (RF), and the Generalised Linear Model (GLM), were applied to predict SSC values. These models’ performance was thoroughly evaluated using cross-validation techniques. The performance of different models was evaluated, showing significant differences according to the metrics used (R2, RMSE, and MAPE). The RF model demonstrated effectiveness and precision. A high R² value of 0.9312, coupled with low RMSE (0.9199 °Brix) and MAPE (3.88%), signifies a strong fit to the data and accurate predictive capabilities. The results of this benchmarking study on predictive models of SSC provide valuable insights into the performance of various models, aiding winegrowers and winemakers in decision making.