|Scientific Name||Agropyron repens|
|Common Names||English: Quackgrass; German: Quecke; French: Chiendent officinal|
|Description||A. repens is an aggressive perennial grass, which reproduces by seed and spreads by a shallow mass of long, slender, branching rhizomes. The plants are very resistant to drought and frost.|
The rhizomes are usually yellowish-white, sharp-pointed, somewhat fleshy and up to 3 m (9.84 ft) long. The auricles clasp the stem, which helps to immediately distinguish it from most other grass weeds. Another characteristic feature is the long and narrow spike.
The first leaf is very long and wide without hairs on the lower surface.
Erect, 30 to 120 cm (11.81 - 47.24 inch), round, more or less curved at the base.
The leaf blades are soft and relatively flat, slightly soft-hairy, dull and mostly dark green, sometimes glaucous, 6 - 30 cm (2.36 - 11.81 inch) long and 3 - 15 mm (0.12 - 0.59 inch) wide. The youngest leaf is rolled, the ligule membranous and short, truncate. Auricles occur at the junction of the sheath and blade. Sheaths are without hair.
The inflorescence is a dense to rather lax spike, like a wheat spike but more slender. Spikelets are compressed, usually with 4 to 8 flowers set in two rows attached to the broad side of the spindle. Glumes are 5 - 15 mm (0.197 - 0.59 inch) long, lanceolate and mostly awn-pointed, lemmas aristate, 6 - 11 mm (0.23 - 0.43 inch) with an awn from less than 1 mm (0.039 inch) up to about 10 mm (0.39 inch).
Summer, rarely through autumn.
Flat, with furrow; hairy at the apex.
Germination occurs all year around, from up to 5 cm (1.97 inch) soil depth. The seedlings begin to develop rhizomes when they have 4 to 6 foliar leaves. The rhizome tips sharp-pointed and can penetrate hard soils, roots, and tubers. Fragmented rhizomes can produce new plants.
Viability Of Seeds
The seed can remain viable up to 4 years under field conditions.
A. repens reproduces vegetatively from rhizomes and by seed, new rhizomes grow primarily in summer (up to 3 m (9.84 ft) per year). Low temperatures and long day conditions in summer induce rhizome growth, new tillers develop in spring and fall. The plants commonly produce 40 - 60 seeds per stem,also immature seed (dough stage) can germinate. Low light intensities induce shoot growth.
A. repens grows in all moderate climate zones of all continents.
The weed prefers many types of soils, mineral as well as organic soils. A. repens is most competitive on fertile soils, which are rich in nitrogen with a good water supply and is less successful on very acid or very dry, shallow soils. A high N-content in the soil favors rhizome growth and bud production.
Additional Crop Information
All arable crops and grassland of moderate climates, mainly in European cereal production.
Quackgrass reduces productivity in crops, rangeland and pasture. It is also a nuisance in lawns, ornamentals and home gardens and reduces growth and germination of neighbouring plants by release of allelochemicals. A seed contamination of seed grain crops reduces the value of the harvest. Reduced tillage favors Quackgrass.
Integrated Crop Management
Tillage is most successful in dry soils that facilitate dessication of the rhizomes. In the spring, tillage should be repeated when plants regrow to approximately 5 cm (1.97 inch) in height. If soils are to wet for tillage, mowing or close grazing has improved control and prevents seed production. Heavy pasturing or mowing before tilling may enhance control.
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