Pest Profile: Redroot Pigweed

Redroot Pigweed

Redroot pigweed is an annual broadleaf weed that has developed resistance to Group 2 herbicides in Western Canada, and Group 5 resistance in the U.S. and Ontario. While the plant is a poor competitor, especially with established plants, it can still significantly reduce yields in less competitive crops, like flax and pulses. One plant can produce more than 100,000 seeds in a season, which stay viable for up to five years, so it’s important to scout early and use multiple modes of action for effective control.

TYPE

  • Annual
  • Broadleaf

IDENTIFICATION

Plants have a long, fleshy, reddish to pink taproot and stems that are erect, light green, branched, 23-35 inches high, rough and angular. The leaves are alternate, stalked, dull green, oval-shaped, rough and 3-4 inches long. Plants have numerous flowers that are small, green and crowded into dense, finger-like spikes.

CONTROL TIPS

  • Redroot pigweed seeds prefer warm temperatures of 20ºC or higher for germination.
  • Crops established before soils warm and weather sets in are very competitive with this weed.
  • Watch growth stages carefully under hot conditions because the plant can quickly advance beyond the recommended stages for herbicide application.

REGISTERED HERBICIDES

TOPLINE®BADGE® llBROMOTRIL® llBROMOTRIL® ll + glyphosate
FORCEFIGHTER® MHOTSHOT™ + glyphosateOUTSHINE®PHANTOM® 240 SL
PRIORITY® + glyphosateRUSH® MSQUADRON®THRASHER® ll


Please read each label to determine which herbicide is appropriate for the crop affected.