Crop Protection Online > Pests - Weed biology<br> <sub>Agro-region: Denmark</sub> - Chrysanthemum segetum

Crop Protection Online

5.12 2024

Weed biology
_{Agro-region: Denmark}

Chrysanthemum segetum

Can be mistaken for

Anthemis arvensis L., which does not have true leaves with a blue bloom.

Artemisia vulgaris L., which has densely hairy true leaves.

Chamomilla suaveolens, which does not have true leaves with a blue bloom.

Tripleurospermum inodorum (L.), which does not have true leaves with a blue bloom.

Characteristics

Cotyledons
Oval with entire leaf margins. Unstalked. Smooth surface. Length approx. 4-6 mm.

True leaves
Oblong with many more or less deep incisions and partitions. Unstalked. Almost smooth surface with a glaucous coating. Length approx. 18-25 mm.

Mature plant
Corn Marigold is a medium-sized plant with a 30-60 cm high, erect stem. The entire plant is bluish green. The diameter of the flower head is approx. 40-50 mm. Seed production: Up to approx. 2,100 seeds per plant.

Seed
Two types exist: ray seed and disc seed. Disc seed: Cylindrical, slightly curved; the diameter decreases at one end. The surface has 8-10 longitudinal ribs. Thousand grain weight approx. 1.5 g. Ray seed: Cylindrical with two opposite ribs, which resemble broad edges of wings. The surface has many ribs. Thousand grain weight approx. 2.2 g.

Biology

Propagation and dispersal
Only through seeds.

Habit
Summer annual.

Importance

The species is frequently found in spring-sown crops throughout Denmark, but can also be found in autumn-sown crops. In all crops in which the plant is found it is an injurious weed, which causes losses, even in small numbers. Because its ripens late, corn Marigold can cause difficulties at harvest in spring-sown cereals.

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

Taxonomy

Compositae.

Names in different languages

Danish :	Okseøje, gul
German :	Saatwucherblume
English :	Corn Marigold
Latin :	Chrysanthemum segetum
Norwegian :	Gullkrage
Swedish :	Gullkrage

Seedling

Early stage

Flower head

Mature plant

Seeds

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Weed biology Agro-region: Denmark