{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,24]],"date-time":"2026-06-24T06:52:55Z","timestamp":1782283975211,"version":"3.54.5"},"reference-count":42,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2021,4,28]],"date-time":"2021-04-28T00:00:00Z","timestamp":1619568000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Spanish Ministry of Science and Innovation","award":["PID2020-113229RB-C44"],"award-info":[{"award-number":["PID2020-113229RB-C44"]}]},{"name":"Government of Navarra","award":["0011-1365-2019-000111"],"award-info":[{"award-number":["0011-1365-2019-000111"]}]},{"name":"CSIC and Universidad P\u00fablica de Navarra","award":["20203299"],"award-info":[{"award-number":["20203299"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Yield prediction is crucial for the management of harvest and scheduling wine production operations. Traditional yield prediction methods rely on manual sampling and are time-consuming, making it difficult to handle the intrinsic spatial variability of vineyards. There have been significant advances in automatic yield estimation in vineyards from on-ground imagery, but terrestrial platforms have some limitations since they can cause soil compaction and have problems on sloping and ploughed land. The analysis of photogrammetric point clouds generated with unmanned aerial vehicles (UAV) imagery has shown its potential in the characterization of woody crops, and the point color analysis has been used for the detection of flowers in almond trees. For these reasons, the main objective of this work was to develop an unsupervised and automated workflow for detection of grape clusters in red grapevine varieties using UAV photogrammetric point clouds and color indices. As leaf occlusion is recognized as a major challenge in fruit detection, the influence of partial leaf removal in the accuracy of the workflow was assessed. UAV flights were performed over two commercial vineyards with different grape varieties in 2019 and 2020, and the photogrammetric point clouds generated from these flights were analyzed using an automatic and unsupervised algorithm developed using free software. The proposed methodology achieved R2 values higher than 0.75 between the harvest weight and the projected area of the points classified as grapes in vines when partial two-sided removal treatment, and an R2 of 0.82 was achieved in one of the datasets for vines with untouched full canopy. The accuracy achieved in grape detection opens the door to yield prediction in red grape vineyards. This would allow the creation of yield estimation maps that will ease the implementation of precision viticulture practices. To the authors\u2019 knowledge, this is the first time that UAV photogrammetric point clouds have been used for grape clusters detection.<\/jats:p>","DOI":"10.3390\/s21093083","type":"journal-article","created":{"date-parts":[[2021,4,28]],"date-time":"2021-04-28T22:29:07Z","timestamp":1619648947000},"page":"3083","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":44,"title":["Grape Cluster Detection Using UAV Photogrammetric Point Clouds as a Low-Cost Tool for Yield Forecasting in Vineyards"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1420-0145","authenticated-orcid":false,"given":"Jorge","family":"Torres-S\u00e1nchez","sequence":"first","affiliation":[{"name":"Grupo Imaping, Instituto de Agricultura Sostenible-CSIC, 14004 C\u00f3rdoba, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5674-1292","authenticated-orcid":false,"given":"Francisco Javier","family":"Mesas-Carrascosa","sequence":"additional","affiliation":[{"name":"Departamento de Ingenier\u00eda Gr\u00e1fica y Geom\u00e1tica, Campus de Rabanales, Universidad de C\u00f3rdoba, 14071 C\u00f3rdoba, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6924-6744","authenticated-orcid":false,"given":"Luis-Gonzaga","family":"Santesteban","sequence":"additional","affiliation":[{"name":"Departamento de Agronom\u00eda, Biotecnolog\u00eda y Alimentaci\u00f3n, Universidad P\u00fablica de Navarra, 31006 Pamplona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9062-4911","authenticated-orcid":false,"given":"Francisco Manuel","family":"Jim\u00e9nez-Brenes","sequence":"additional","affiliation":[{"name":"Grupo Imaping, Instituto de Agricultura Sostenible-CSIC, 14004 C\u00f3rdoba, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Oihane","family":"Oneka","sequence":"additional","affiliation":[{"name":"Departamento de Agronom\u00eda, Biotecnolog\u00eda y Alimentaci\u00f3n, Universidad P\u00fablica de Navarra, 31006 Pamplona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ana","family":"Villa-Llop","sequence":"additional","affiliation":[{"name":"Departamento de Agronom\u00eda, Biotecnolog\u00eda y Alimentaci\u00f3n, Universidad P\u00fablica de Navarra, 31006 Pamplona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4761-1012","authenticated-orcid":false,"given":"Maite","family":"Loidi","sequence":"additional","affiliation":[{"name":"Departamento de Agronom\u00eda, Biotecnolog\u00eda y Alimentaci\u00f3n, Universidad P\u00fablica de Navarra, 31006 Pamplona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Francisca","family":"L\u00f3pez-Granados","sequence":"additional","affiliation":[{"name":"Grupo Imaping, Instituto de Agricultura Sostenible-CSIC, 14004 C\u00f3rdoba, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,4,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"409","DOI":"10.5344\/ajev.1993.44.4.409","article-title":"Environmental and Management Practices Affecting Grape Composition and Wine Quality-A Review","volume":"44","author":"Jackson","year":"1993","journal-title":"Am. 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