Agronomy Library > Forages & Forage Seed

Herbicide-tolerant canola: weed control and yield comparisons in western Canada
Author: K. N. Harker, R. E. Blackshaw, K. J. Kirkland, D. A. Derksen, and D. Wall
Date Created: June 07, 2000
Last Reviewed: February 14, 2007
Document Source: Canadian Journal of Plant Science, Volume 80: 647-654 Summary · Field experiments were conducted at five western Canadian locations in 1996 and 1997 to compare weed control and canola (Brassica napus L.) seed yields in the three major herbicide-tolerant canola (HTC) systems. · The main objective of this study was to determine if significant weed control and yield advantages could be expected by using herbicides "designated" for HTC compared to a more "standard" application of sethoxydim plus ethametsulfuron. · In 3 of 10 site-years, glyphosate in Quest canola and imazethapyr/imazamox in 45A71 canola provided a yield advantage over the standard treatment. The yield advantages were restricted to the Lacombe and Lethbridge sites and ranged from 13 to 39% increases over the sethoxydim plus ethametsulfuron treatments. · Among the HTC, weed control was usually greatest with glyphosate, followed by imazethapyr/imazamox, and then glufosinate. Glufosinate efficacy was often restricted due to advanced growth stages on some weeds. · The standard treatment of sethoxydim plus ethametsulfuron did not provide better weed control than glyphosate, but in some cases did improve weed control compared to imazethapyr/imazamox or glufosinate. · The HTC provide growers with new opportunities for the control of difficult weeds along with the option to employ in-crop herbicides with new modes of action in canola.