Field experiments were conducted from 1986 to 1988 at Lacombe and Lethbridge, Alberta and Scott, Saskatchewan to determine growth and yield response of canola to mixtures of ethametsulfuron with specific grass herbicides. Ethametsulfuron did not usually cause canola injury when mixed with sethoxydim. However, ethametsulfuron mixtures with the following grass herbicides listed in decreasing order of injury potential, often caused canola injury and yield loss: haloxyfop > fluazifop > fluazifop-P > quizalofop > quizalofop-P. Canola yield losses were severe in some experiments, ranging from 59% with quizalofop mixtures to 97% with haloxyfop mixtures; in other experiments, the same mixtures did not cause significant yield losses. ‘Tobin,’ a Brassica rapa cultivar, tended to be more susceptible to injury than the B. napus cultivars ‘Pivot’ and ‘Westar.’ Canola injury symptoms were consistent with those expected from sulfonylurea herbicides. Therefore, we suggest that specific grass herbicides differentially impair the ability of canola to metabolize ethametsulfuron to inactive forms.

Crambe has gained interest as an alternative crop for industrial oil production. No herbicides are currently registered in crambe and weed control strategies need to be identified if crambe is to become a viable crop. Field experiments were conducted to determine crambe tolerance to several herbicides. Crambe was tolerant to soil-applied trifluralin, pendimethalin, and cinmethylin, or DPX-A7881 applied postemergence. Postemergence applications of chlorimuron or imazethapyr were injurious to crambe.