Fate and transport of herbicides used in growing transgenic canola in Quebec
Authors: Syan, Hs, S Prasher, J Singh
Description: Canola is the second most important oilseed crop after soybean. More than 90% of the canola crop grown in the world is transgenic. Before this crop is grown more extensively in Quebec, there is a need to assess environmental risks associated with genetically engineered canola, mainly Roundup Ready (glyphosate-tolerant) and Liberty Link (glufosinate-resistant) varieties. We have conducted a field study to compare and contrast the fate and transport of glyphosate and glufosinate herbicides in soil, applied to transgenic canola, with trifluralin, a herbicide commonly used with non-transgenic (conventional) canola cultivar, at the Macdonald Campus Farm of McGill University. Agronomic data was also collected in each test plot. Three treatments were assigned, in quadruplicate, in a completely randomized block design, with non-transgenic canola line as control. Soil samples were collected from two depths, 0-15 cm and 15-30 cm, at different times (after 1, 7 and 20 days of herbicide application) during the growing season. Significant yield differences were observed between herbicide-resistant and conventional canola. Yield performance of all three herbicides were as follows: Roundup Ready > Liberty Link > Avalanche (conventional canola cultivar). Glyphosate was found to be the least persistent herbicide, while trifluralin was found to have longer persistence in the soil. Trifluralin was also found at the lower depth (15-30 cm) at 7 and 20 days after herbicide application.
Keywords: glyphosate, transgenic canola, herbicide, persistence , soil
Technical field: technical_fields_app7
Session name: Soil and water