Palmer amaranth is a competitive and aggressive pigweed species that poses a major threat to North Dakota crop production.
Palmer amaranth and waterhemp are difficult to control pigweeds that are found in North Dakota. This publication focuses on how to identify these species from other pigweeds, and focuses on biology of these weeds that makes them difficulty to control. General management principles are also discussed.
Potential Impact[]
“Palmer amaranth’s prolonged emergence period, rapid growth rate, prolific seed production, and propensity to evolve herbicide resistance quickly makes this the most pernicious, noxious, and serious weed threat that North Dakota farmers have ever faced.” - Rich Zollinger, Retired NDSU Extension Weed Scientist
Palmer amaranth is a competitive and aggressive pigweed species that poses a major threat to North Dakota crop production. Here's why.
- Grows aggressively: Can grow 2 to 3 inches per day in optimum conditions
- Can grow to 6-8 feet tall
- Has reduced yield up to 91 percent in corn and 79 percent in soybean
- Prolific seed producer: Up to 1 million seeds per plant
- Emerges throughout the growing season
- Very prone to herbicide resistance (multiple modes of action)
“It’s the only weed I’ve seen that can drive a farmer out of business.” - Bill Johnson, Purdue University Extension Weed Specialist
Amaranthaceae (Pigweed) Identification