Agronomy Library > Event & Field Reports

Preharvest Applications of Glyphosate for Yellow Toadflax (Linaria vulgaris) Control
Author: Mirza N. Baig, A. Lloyd Darwent, K. Neil Harker, and John T. O’Donovan
Date Created: June 09, 1999
Last Reviewed: February 14, 2007
Document Source: Weed Technology. Volume 12 Summary · The effectiveness of preharvest applications of glyphosate on yellow toadflax was evaluated at five sites in Alberta from 1992 to 1994. · At each site, glyphosate at 0.9 to 1.8 kg ae/ha was applied with or without nonionic surfactant and/or ammonium sulfate. Glyphosate at 2.7 kg/ha and glufosinate at 0.6 kg ai/ha were applied without additional adjuvants. The treatments were applied 7 to 10 d before crop harvest, when the majority of the yellow toadflax was in a flowering stage. · Eleven to 12 months after glyphosate application, yellow toadflax density was reduced by more than 80%. · In most instances, there was no advantage in increasing the glyphosate rate above 0.9 kg/ha. · The addition of nonionic surfactant and/or ammonium sulfate did not enhance glyphosate activity. · Glufosinate did not control yellow toadflax in the year following treatment. · Barley, canola, and flax yields in the year following applications were significantly higher in all preharvest glyphosate-treated plots than in untreated plots.