Planteværn Online > Skadevoldere - Weed biology<br> <sub>Agro-region: Denmark</sub> - Common Orache

Crop Protection Online

19.12 2024

Weed biology
_{Agro-region: Denmark}

Common Orache

Can be mistaken for

Fat Hen, which is reddish on the underside of the dicotyledon leaves.

Characteristics

Cotyledons
Oblong to lancet-shaped with entire leaf margins. Unstalked. Smooth surface. Length approx. 15 mm.

True leaves
The first true leaves are oblong to lancet-shaped with almost entire leaf margins. Stalked. The surface is covered with white sap hairs, which resemble small, clear Pearls. Later true leaves are lancet-shaped in outline with serrate leaf margins, at the base often with 2 large teeth. Stalked. The surface is covered with sap hairs. Length approx. 20 mm.

Mature plant
Common orache can develop into a high (approx. 20-80 cm) and vigorous plant. The lower branches of the stem often trail along the ground. The species is very similar to Fat Hen, but can be distinguished from this by the 2 distinct teeth at the base. The diameter of the flower is approx. 1 mm. Seed production: Up to approx. 6,000 seeds per plant.

Seed
Roundish, flattened seed, which is very similar to the seed of Fat Hen. The surface is coated with a greyish-white layer of wax, which can easily be rubbed off. The seed is often surrounded by remnants of a sPear tip-like perianth. Thousand grain weight approx. 1.4 g.

Biology

Propagation and dispersal
Only through seeds.

Habit
Summer annual.

Importance

The species is frequently found in spring-sown crops throughout Denmark. In cereal crops, Oil-seed Rape and horse bean, common orache usually has no major influence on yield. However, in open crops the plant can be both troublesome and cause losses even at small densities.

For treatment options, consult 'Herbicides Across'.
For more options, consult 'Main Menu'.

Taxonomy

Chenopodiaceae.

Names in different languages

Danish :	Mælde, svine
German :	Gemeine Melde
English :	Common Orache
Latin :	Atriplex patula L.
Norwegian :	Svinemelde
Swedish :	Vägmålla

Seedling

Early stage

Flower

Mature plant

Seeds

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Weed biology Agro-region: Denmark