Waterhemp growing between soybean plants

An AgWeb poll asked about 400 growers what their “top weed nemesis” was. Waterhemp took the top spot, earning 35% of the votes. But why is waterhemp so tough to control?

Waterhemp is a small-seeded broadleaf weed that compensates for its tiny seed size with a higher growth rate than most weeds. Its lightweight seeds thrive in minimum and no-till situations, where they quickly germinate near the soil surface or in crop residue. Waterhemp plants generally produce about 250,000 seeds per plant, although some plants can produce as many as 1 million seeds, making them a prevalent and costly problem if you grow corn and soybeans.

Waterhemp emerges throughout the growing season, and a higher percentage of this plant appears later in the season than most annual summer weeds. This allows waterhemp to escape many preemergence herbicide applications, and often allows this species to flourish after post-emergence applications of non-residual herbicides like glyphosate. Waterhemp plants that are left to go to seed can quickly populate the soil seed bank with millions of seedlings, spreading resistance and ensuring it remains a costly problem for years to come.

A Clean Field Means Less Competition

For strong weed control, we recommend a post-emergence corn herbicide that targets both large-seeded and small-seeded broadleaves with multiple active ingredients. This will deliver faster knockdown and enhance control of tough-to-control weeds like waterhemp.

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