{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,14]],"date-time":"2026-06-14T09:42:34Z","timestamp":1781430154901,"version":"3.54.1"},"reference-count":26,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2015,3,30]],"date-time":"2015-03-30T00:00:00Z","timestamp":1427673600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Non-chemical weed control methods need to be directed towards a site-specific weeding approach, in order to be able to compete the conventional herbicide equivalents. A system for online weed control was developed. It automatically adjusts the tine angle of a harrow and creates different levels of intensity: from gentle to aggressive. Two experimental plots in a maize field were harrowed with two consecutive passes. The plots presented from low to high weed infestation levels. Discriminant capabilities of an ultrasonic sensor were used to determine the crop and weed variability of the field. A controlling unit used ultrasonic readings to adjust the tine angle, producing an appropriate harrowing intensity. Thus, areas with high crop and weed densities were more aggressively harrowed, while areas with lower densities were cultivated with a gentler treatment; areas with very low densities or without weeds were not treated. Although the weed development was relatively advanced and the soil surface was hard, the weed control achieved by the system reached an average of 51% (20%\u201391%), without causing significant crop damage as a result of harrowing. This system is proposed as a relatively low cost, online, and real-time automatic harrow that improves the weed control efficacy, reduces energy consumption, and avoids the usage of herbicide.<\/jats:p>","DOI":"10.3390\/s150407691","type":"journal-article","created":{"date-parts":[[2015,3,30]],"date-time":"2015-03-30T10:50:23Z","timestamp":1427712623000},"page":"7691-7707","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":23,"title":["A Non-Chemical System for Online Weed Control"],"prefix":"10.3390","volume":"15","author":[{"given":"Victor","family":"Rueda-Ayala","sequence":"first","affiliation":[{"name":"Department of Weed Science (360b), University of Hohenheim, 70599 Stuttgart, Germany"},{"name":"Proyecto Prometeo\u2013SENESCYT. General Coordination of Laboratories, Agencia Ecuatoriana de Aseguramiento de la Calidad del Agro, AGROCALIDAD, V\u00eda Interoce\u00e1nica, km 14 1\/2 y Eloy Alfaro, Granja MAGAP, EC170184 Tumbaco, Ecuador"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gerassimos","family":"Peteinatos","sequence":"additional","affiliation":[{"name":"Department of Weed Science (360b), University of Hohenheim, 70599 Stuttgart, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Roland","family":"Gerhards","sequence":"additional","affiliation":[{"name":"Department of Weed Science (360b), University of Hohenheim, 70599 Stuttgart, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dionisio","family":"And\u00fajar","sequence":"additional","affiliation":[{"name":"Institute of Agricultural Sciences, Consejo Superior Investigaciones Cient\u00edficas, CSIC, Serrano 115b, 28006 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2015,3,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"385","DOI":"10.1046\/j.1365-3180.2003.00349.x","article-title":"Real-time weed detection, decision making and patch spraying in maize, sugar beet, winter wheat and winter barley","volume":"43","author":"Gerhards","year":"2003","journal-title":"Weed Res."},{"key":"ref_2","unstructured":"Heap, I.M. 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