Testing and analysing decision rules for site-specific weed control in malt barley (Hordeum vulgare L.) using a geographic information system

Publication Type

Journal contribution

Authors

Gerhards, R. and D. Dicke and H. Oebel

Year of publication

2005

Published in

Zeitschrift für Pflanzenkrankheiten und Pflanzenschutz

Band/Volume

112/5

ISBN / ISSN / eISSN

0340-8159

Page (from - to)

447-456

Field experiments were conducted to test and analyse decision rules for site-specific weed control in malt barley using a geographic information system (GIS). Weed seedling distribution was assessed prior to post-emergence herbicide application. A low and a high weed density threshold were set for site-specific weed management using a GPS-controlled boom sprayer. Application maps were created to direct the sprayer. The sprayer varied the herbicide dosage and mixture depending on the informa- tion in the application map. Site-specific weed control resulted in a total reduction of 54 % herbicides directed against Galium aparine and Cirsium arvense, 23 to 96 % herbicides sprayed against grass weeds and 7 to 93 % herbicides applied against broad-leaved weeds. Weed species in the field did not cause significant grain yield reduction. However, C. arvense and A. fatua patches with densities higher than 5 plants/m² reduced the grain protein content and size sufficiently to result in a complete loss of valuable malting premiums.