Kochia

Goosefoot family (Chenopodiaceae family):

Kochia scoparia (L.) Schrad.

EPPO code:

KCHSC

Other names:

Belevedere, red belvedere, Mexican fireweed, summer-cypress

Species information

Lifecycle:

Annual.

Propagation:

Reproduces by seed.

Emergence:

Seedlings emerge in the spring.

Habitat:

Kochia is rarely found in Ontario, however, more recently it has shown up in new seedling alfalfa stands, presumably from contaminated alfalfa seed from Western Canada.

Competitiveness:

Kochia densities of six plants/m2 did not reduce yields of oat, but in two of five years a density of 30 plants/m² caused between 12–31% yield loss (Manthey et al., 1996). In 2014, Lewis and Gulden identified a 5% yield loss action threshold in sunflower at a kochia density of four plants/m² when they emerged at the same time as the crop.

Resistance:

Most populations in Western Canada are resistant to group 2 herbicides and some are resistant to glyphosate. Some Ontario populations are group 2 resistant but there are no known cases of glyphosate resistant kochia in the province.

Identification clues

Seedling

Cotyledons:

Elongated, without a stalk.

First leaves:

Kochia’s first leaves are elongated and somewhat club-shaped. They are covered in soft, dense hairs. Leaves form a basal rosette.

Mature leaves:

Mature leaves grow in alternate orientation, are elongated and somewhat club-shaped, and covered in soft, dense hairs.

Mature plant

Stems:

Its stem is erect, much-branched, and often red-tinged with green. It is covered in short, soft white hairs.

Flowers:

Kochia’s flowers are subtle, small, round, green and clustered. In many ways, they are like the flowers of kochia’s close relative, lamb’s-quarters.

Seeds:

Kochia has bladder-like seed pods with irregularly-shaped brown seeds. The seeds have yellow markings and are grooved on each side.

Roots:

Taproot with branched fibrous roots.