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Early Kochia Control Important

Originating from eastern Europe and Asia, Kochia was brought to North America in the 1800’s as an ornamental garden plant. Often called a tumbleweed in the winter as it blows across the plains. Characteristics include dense hairy, club-shaped leaves,

Although Kochia is not a regulated species on the Weed Control Act, Rocky View County residents are encouraged to control it. Kochia’s ability to grow quickly and produce tens of thousands of seeds, coupled with the development of herbicide resistance, have accelerated the spread across Alberta.

Commonly found in cereal crops, road edges and disturbed soil, kochia will outgrow crops and grasses. Thick clusters of plants can easily reach 4 to 5 feet tall in a short time even in dry conditions. In the fall kochia turns red and hardens off and winter winds then break off the dry plant sending it across open ground dispersing its 25,000 seeds.

Decades of herbicide application has developed into group 2, 4, 9 and 14 herbicide resistance. This has made it difficult to get control even with multiple herbicide group tank mixes. The best defense is early detection and then early herbicide application. Some group 2 and 4 herbicides with 2,4-D and dicamba are effective on plants under 15cm tall. Mixed 2,4-D and fluroxypyr herbicides could extend that control up to 50cm tall. If herbicide application doesn’t work or plant stage is to advanced, the only option may be mechanical control such as hand pulling, cultivation or mowing.

In the past kochia has been used to get livestock through drought conditions. However, caution should be used if used as feed as several studies have shown that even in a short period oxalate poisoning can occur. Symptoms include laboured breathing, depression, weakness, coma and death.

Kochia will be an ongoing problem for producers and infrastructure maintenance. But with a good integrated pest management plan and early detection progress can be made to limit the spread of kochia.

To address this issue on Rocky View County lands, Agricultural Services specifically targets kochia as part of our annual roadside weed control program.

Posted in: Agriculture