Planteværn Online > Skadevoldere - Weed biology<br> <sub>Agro-region: Denmark</sub> - Italian Rye-grass SU-res
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26.4 2024 undefined

Weed biology
Agro-region: Denmark

Italian Rye-grass SU-res Previous page Next page

Go to identification key for weeds

Can be mistaken for

Italian Rye-grass that is morphologically identical but not resistant to ALS-herbicides

Resistance to herbicides

There have been significant populations of this weed in Denmark, which requires special considerations in the control. Read more here.

Characteristics

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.

Seed
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 and descriptions can be stdied in 'Den Virtuelle Floran'.

Biology

Biology
Propagation and dispersal: Mainly through seeds.

Habit
There are annual, biannual and perennial types.

Importance

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'.

Taxonomy

Graminae.

Names in different languages

Danish : Rajgræs, ital. ALS-res
German : Vielblütiges Weidelgras SU-res
English : Italian Rye-grass SU-res
Latin : Lolium multiflorum Lam. SU-res
Norwegian : Italiensk raigras SU-res
Swedish : Italienskt rajgräs SU-res
Italian Rye-grass SU-res: Very early stage
Very early stage
Italian Rye-grass SU-res: Early stage
Early stage
Italian Rye-grass SU-res: Leaf sheath
Leaf sheath
Italian Rye-grass SU-res: Leaf section
Leaf section
Italian Rye-grass SU-res: Spikelets
Spikelets
Italian Rye-grass SU-res: Mature plant
Mature plant
Italian Rye-grass SU-res: Seeds
Seeds
 
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