Is Early Season Control the Key to Conquering Herbicide-Resistant Kochia?
The latest issue of the journal Weed Science contains an article with intriguing new insights about the control of herbicide-resistant kochia, a weed that competes with both dryland and irrigated crops across the Great Plains states.
A two-year study of kochia emergence patterns and seed persistence showed that more than 95 percent of kochia seeds failed to remain viable for more than two years. Since the seeds are so short-lived, researchers say aggressively managing kochia with cultural and mechanical controls could quickly deplete the seedbank and reduce the weed’s impact.
They recommend adoption of preemergence control techniques initiated in the fall or by early February to address the first flush of kochia and prevent seed production. Fall-established cover crops can create a canopy that suppresses the density of kochia seedlings. Early season tillage can also be effective. The study showed seeds unearthed during tillage had a very low percentage of viability.
Growers may even want to adopt stale seedbed techniques and allow weed seeds to germinate so they can be treated prior to planting crops. Researchers caution, though, that kochia continues to emerge into mid-summer. Extended management may be needed.
You can learn more about the research study and recommendations for effective control of herbicide-resistant kochia in the article “Kochia (Kochia scoparia) Emergence Profiles and Seed Persistence Across the Central Great Plains” found in Weed Science Vol. 65, Issue 5, September 2017.