Waterhemp is a notorious member of the pigweed family, known for its tough-to-manage resilience and ability to develop resistance. The good news is, farmers can still fight waterhemp with proper use of existing technologies and effective management strategies.1
Waterhemp is most common in the Midwest but is found from Texas to Maine.2,3
Season-long competition by waterhemp can reduce soybean yields by 44%4,5
Waterhemp can grow up to 1-1/4 inches per day. Seedlings are hairless and have longer, pear-shaped leaves that look waxy or glossy.5
Waterhemp can range from mere inches up to 12 feet tall but generally grows to about 4 or 5 feet in most agronomic settings.3
A prolific seed producer, generally producing 250,000 seeds per plant, but some can produce 1 million or more under optimal conditions.4
Waterhemp has a remarkable ability to adapt to control tactics and has developed resistance to many different classes of herbicides. It is critical to follow your management practices vigilantly to avoid this troublesome weed taking over your fields. Cultural practices that enhance the competitiveness of the crop, such as narrow row spacing or optimal soybean planting populations, help improve the consistency of your herbicide program.4
to diversify herbicide programs and weed control strategies.
with a burndown herbicide or tillage.
using a residual product within 2 weeks before planting or prior to crop emergence.
before weeds grow taller than 4 inches.
If weeds escape, use tillage or physically remove them before plants produce seed.
The key to controlling waterhemp is all about the right timing and the right products. Apply a postemergence herbicide 20-30 days after planting, when waterhemp weeds are less than 4 inches tall and easier to control. Choose the right products with the right modes of action to give your crops the best defense against weeds:
With the right postemergence application, as part of a complete strategy, you can keep better control of weeds and help protect your crops to canopy.
Choose the system that gives you advanced weed control and yield potential.
1 Dietz, J., Successful Farming (Sep. 23, 2015). The good, the bad, and the ugly of waterhemp management. Retrieved from http://www.agriculture.com
2 University of Missouri Division of Plant Sciences (Sep. 12, 2019). Weed ID Guide, Common waterhemp. Retrieved from http://www.weedid.missouri.edu
3 Nordby, D., Hartzler, B., Bradley, K. (November 2007). Biology and management of waterhemp. The Glyphosate, Weeds, and Crop Series. GWC-13. Retrieved from http://www.weedscience.missouri.edu
4 Take Action. United States Soybean Board (Sep. 12, 2019). Waterhemp management in soybeans. Retrieved from http://www.weedscience.missouri.edu
5 Crop Science (Sep. 12, 2019). How to tackle waterhemp. Retrieved from http://www.cropscience.bayer.us