Influence of herbicide-resistant canola on the environmental impact of weed management

• Published in: Pest management science Vol. 61; no. 1; pp. 47 - 52
• Main Authors: Brimner, T.A, Gallivan, G.J, Stephenson, G.R
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 2005; Wiley; Wiley Subscription Services, Inc
• Subjects: Agriculture - methods; application rate; Biological and medical sciences; Brassica napus - drug effects; Brassica napus var. napus; Brassica rapa - drug effects; Canada; canola; Chemical control; Drug Resistance; environmental assessment; Environmental impact; environmental impact quotient; Environmental Monitoring; Fundamental and applied biological sciences. Psychology; herbicide resistance; Herbicides; Herbicides - pharmacology; Parasitic plants. Weeds; pesticide use; Phytopathology. Animal pests. Plant and forest protection; Plant resistance; Rape plants; Time Factors; transgenic plants; usage statistics; varieties; weed control; Weeds; Canada; North America; America; pesticide use; Pesticides; Herbicide; canola; Brassica; Sensitivity resistance; Cruciferae; Dicotyledones; Environment impact; Angiospermae; environmental impact quotient; Spermatophyta; Pesticide resistance; herbicide resistance; Oil plant (vegetal); Chemical weed control
• ISSN: 1526-498X; 1526-4998
• DOI: 10.1002/ps.967

The growth of herbicide-resistant canola varieties increased from 10% of the canola area in Canada in 1996, when the technology was first introduced, to 80% in 2000. From 1995 to 2000, the amount of herbicide active ingredient applied per hectare of canola declined by 42.8% and the Environmental Impact (EI) per hectare, calculated using the Environmental Impact Quotient for individual herbicides and the amounts of active ingredients applied, declined 36.8%. The amount of herbicide active ingredient per hectare applied to conventional canola was consistently higher than that applied to herbicide-resistant canola each year between 1996 and 2000. Similarly, the EI of herbicide use per hectare in conventional canola was higher than that of herbicide-resistant canola during the same time period. Since 1996, herbicide use has shifted from broadcast applications of soil-active herbicides to post-emergence applications of herbicides with broad-spectrum foliar activity. The decline in herbicide use and EI since the introduction of herbicide-resistant varieties was due to increased use of chemicals with lower application rates, a reduced number of applications and a decreased need for herbicide combinations.