title: Quantifying efficacy and limits of unmanned aerial vehicle (UAV) technology for weed seedling detection as affected by sensor resolution.
abstract: In order to optimize the application of herbicides in weed-crop systems, accurate and timely weed maps of the crop-field are required. In this context, this investigation quantified the efficacy and limitations of remote images collected with an unmanned aerial vehicle (UAV) for early detection of weed seedlings. The ability to discriminate weeds was significantly affected by the imagery spectral (type of camera), spatial (flight altitude) and temporal (the date of the study) resolutions. The colour-infrared images captured at 40 m and 50 days after sowing (date 2), when plants had 5-6 true leaves, had the highest weed detection accuracy (up to 91%). At this flight altitude, the images captured before date 2 had slightly better results than the images captured later. However, this trend changed in the visible-light images captured at 60 m and higher, which had notably better results on date 3 (57 days after sowing) because of the larger size of the weed plants. Our results showed the requirements on spectral and spatial resolutions needed to generate a suitable weed map early in the growing season, as well as the best moment for the UAV image acquisition, with the ultimate objective of applying site-specific weed management operations.
authors.affiliation: Institute for Sustainable Agriculture, IAS-CSIC, P.O. Box 4084, 14080 Córdoba, Spain. jmpena@ias.csic.es.
authors.forename: José M
authors.initials: JM
authors.lastname: Peña
authors.affiliation: Institute for Sustainable Agriculture, IAS-CSIC, P.O. Box 4084, 14080 Córdoba, Spain. jtorres@ias.csic.es.
authors.forename: Jorge
authors.initials: J
authors.lastname: Torres-Sánchez
authors.affiliation: Institute for Sustainable Agriculture, IAS-CSIC, P.O. Box 4084, 14080 Córdoba, Spain. aserrano@ias.csic.es.
authors.forename: Angélica
authors.initials: A
authors.lastname: Serrano-Pérez
authors.affiliation: Institute for Sustainable Agriculture, IAS-CSIC, P.O. Box 4084, 14080 Córdoba, Spain. anadecastro@ias.csic.es.
authors.forename: Ana I
authors.initials: AI
authors.lastname: de Castro
authors.affiliation: Institute for Sustainable Agriculture, IAS-CSIC, P.O. Box 4084, 14080 Córdoba, Spain. flgranados@ias.csic.es.
authors.forename: Francisca
authors.initials: F
authors.lastname: López-Granados
mesh_terms: D000383:Agriculture; D000401:Aircraft; D006801:Humans; D057685:Plant Weeds / Q000254:growth & development; D058998:Remote Sensing Technology; D036226:Seedlings; D058728:Weed Control