Canada proposes to approve trifludimoxazin-based herbicides

Health Canada’s Pest Management Regulatory Agency (PMRA), under the authority of the Pest Control Products Act, is proposing registration for the sale and use of Tirexor Herbicide Technical, Vulcarus and Voraxor, containing the technical grade active ingredient trifludimoxazin, to control weeds in barley, field corn, field pea, soybean, wheat, lentil, and chemfallow.

Trifludimoxazin is a herbicide that inhibits synthesis of protoporphyrinogen oxidase (PPO). The lack of PPO damages cell membranes, which leads to plant death. Under active growing conditions, susceptible emerged weeds develop injury symptoms within hours of exposure and die within 3–5 days. Susceptible emerging weed seedlings usually die as they reach the soil surface or shortly after emergence.

Vulcarus and Voraxor provide burndown control of several broadleaf weeds with soil residual activity to suppress secondary weed flushes in barley, field corn, field pea, soybean, wheat, lentil, and in chemfallow situations.

Vulcarus is formulated as a suspension concentrate with trifludimoxazin. It provides burndown control of cleavers, kochia, lamb’s-quarters, volunteer canola, and wild buckwheat and suppression of secondary flushes of kochia, lamb’s-quarters, redroot pigweed, volunteer canola, and wild mustard in barley, field corn, field pea, soybean, and wheat (spring, durum, and winter) and in chemfallow.

Voraxor is formulated as a suspension concentrate with trifludimoxazin and the registered active ingredient saflufenacil. It provides burndown control of Canada fleabane, cleavers, kochia, lamb’s-quarters, narrow-leaved hawk’s beard, redroot pigweed, round-leaved mallow, shepherd’s purse, stinkweed, volunteer canola, wild buckwheat, and wild mustard and further suppression of secondary weed flushes in barley, field corn, lentil, field pea, soybean, and wheat (spring, durum, and winter) and in chemfallow.

Registrations of Vulcarus and Voraxor will provide farmers with options for pre-plant or pre-emergent burndown control of broadleaf weeds, including key weeds present in agricultural systems, in the early season with soil residual activity. Application of Vulcarus or Voraxor reduces early season weed competition to the emerging crop, allowing the crop to benefit from additional moisture, nutrients, and light that would otherwise be captured by weeds. Management of weeds at this time is critical, as the crop does not compete well with weeds until crop canopy closure. As Vulcarus and Voraxor have soil residual activity, the reduction in competition of weeds with the crop is extended.

Before making a final registration decision on trifludimoxazin, Vulcarus and Voraxor, Health Canada’s PMRA will consider any comments received from the public in response to PRD2020-15. Health Canada will accept written comments before December 12, 2020.