Crop Protection Online > Pests - Weed biology<br> <sub>Agro-region: Denmark</sub> - Lolium multiflorum
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21.7 2024 undefined

Weed biology
Agro-region: Denmark

Lolium multiflorum Previous page Next page

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Early stages
Rolled vernation. The leaves are broad, soft and limp with distinct leaf ribs and a bright, shiny underside. Rough along the outer third of the leaf margin. Large and clasping leaf teeth. The ligule is short, approx. 2 mm.

Can be mistaken for: Perennial Rye-grass which has smaller leaf teeth and valvate vernation.

Mature plant
Italian Rye-grass is a large grass species with 30-70 cm high, erect straws. The leaf sheaths are almost round, and the leaf undersides are shiny. Each spikelet often has more than 10 flowers, and unlike Perennial Rye-grass the spikelets have long awns. The edge of the spikelets face the straw unlike Common Couch-grass of which the surface of the spikelet face the straw. Seed production: Up to approx 600 seeds per plant.

Oblong, almost rectangular in circumference. 1-7 mm long awn. The lemma is 5-nerved, slightly domed and tough. The rachilla is short (1-2 mm), adjoining and with a diagonally cut and bowl-shaped top. Naked seeds occur. Thousand grain weight approx. 2.3 g.

Additional pictures can be found in Den Virtuelle Floran.


Propagation and dispersal: Mainly through seeds.

There are annual, biannual and perennial types.


The plant occurs especially on properties where it is part of the crop rotation as either roughage or seed crop. As a weed Italian Rye-grass occurs in all types of crop and it causes even larger losses than Perennial Rye-grass. In seed fields with Perennial Rye-grass, Cock’s-foot and Fescue it is undesirable because it is difficult to separate the seeds.

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

Names in different languages

Danish : Rajgræs, ital.
German : Vielblütiges Weidelgras
English : Italian Rye-grass
Latin : Lolium multiflorum
Norwegian : Italiensk raigras
Swedish : Italienskt rajgräs

Lolium multiflorum: Very early stage
Very early stage
Lolium multiflorum: Early stage
Early stage
Lolium multiflorum: Leaf sheath
Leaf sheath
Lolium multiflorum: Leaf section
Leaf section
Lolium multiflorum: Spikelets
Lolium multiflorum: Mature plant
Mature plant
Lolium multiflorum: Seeds

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