Site-specific wild oat (Avena fatua L.) management

• Published in: Canadian journal of plant science 2012-09, Vol.92 (5), p.923-931
• Main Authors: Beckie, H. J, Shirriff, S
• Format: Article
• Language: English
• Subjects: application d'herbicide selon le site; Avena fatua; Avena fatua L; biomass; Brassica napus; Brassica napus L; canola; cropping sequence; economic threshold; ecoregions; folle avoine; grasslands; growers; growing season; herbicides; Landscape; landscape position; landscapes; oats; pesticide application; Relief; semiarid zones; site-specific herbicide application; soil properties; soil water; spring; Triticum aestivum; Triticum aestivum L; Weed; weeds; wheat; wild oat
• ISSN: 0008-4220; 1918-1833; 1918-1833
• DOI: 10.1139/CJPS2012-007

Beckie, H. J. and Shirriff, S. 2012. Site-specific wild oat (Avena fatuaL.) management. Can. J. Plant Sci. 92: 923-931. Variation in soil properties, such as soil moisture, across a hummocky landscape may influence wild oat emergence and growth. To evaluate wild oat emergence, growth, and management according to landscape position, a study was conducted from 2006 to 2010 in a hummocky field in the semiarid Moist Mixed Grassland ecoregion of Saskatchewan. The hypothesis tested was that wild oat emergence and growth would be greater in lower than upper slope positions under normal or dry early growing season conditions. Three herbicide treatments were imposed on the same plots each year of a 2-yr canola (Brassica napus L.) - wheat (Triticum aestivum L.) sequence: (1) nontreated (weedy) control; (2) herbicide application to upper and lower slope positions (i.e., full or blanket application); and (3) herbicide application to lower slope position only. Slope position affected crop and weed densities before in-crop herbicide application in years with dry spring growing conditions. Site-specific wild oat herbicide application in hummocky fields in semiarid regions may be justified based on results of wild oat control averaged across slope position. In year 2 of the crop sequence (wheat), overall (i.e., lower and upper slope) wild oat control based on density, biomass, and dockage (i.e., seed return) was similar between site-specific and full herbicide treatment in 2 of 3 yr. Because economic thresholds have not been widely adopted by growers in managing wild oat, site-specific treatment in years when conditions warrant may be an appropriate compromise between no application and blanket herbicide application.