Couchgrass

Seed and fruit

The seeds are spindle-shaped.

No rate and no spray timing here: both come from the label and the register.

Agronomy

The rhizomatous weed is destroyed by post-harvest stubble cultivation with disc harrows to a depth of 12–15 cm in two directions. Then, when white shoots appear, the field is ploughed to the depth of the plough layer.

Yield loss

It has high allelopathic activity, and this helps it to crowd out other species.

Life form

• A perennial weed. Some small-grain cereal crops are infested with it.
• Adventitious feeding roots grow from the nodes of the rhizomes.
• A rhizomatous weed. It often infests oilseed rape crops, in particular winter oilseed rape.
• The rhizomes branch sympodially.
• It belongs to the shallow-rhizome weeds: the rhizomes are concentrated in the 0–30 cm soil layer.
• If the plant develops from seed, rhizomes and new stems appear from the tillering node 40–50 days after emergence. The rhizomes first go deeper into the soil, then come up to the surface as above-ground shoots, and the following year, after flowering and fruiting, they die off.
• It reproduces vegetatively both from whole rhizomes and from their fragments after mechanical soil cultivation.

Emergence

• New rhizomes start to sprout in spring, when the soil warms up to 5–8 °C.
• On old yellow-brown rhizomes the buds form shoots mainly in spring, while on young white rhizomes they do so throughout the growing season, right up to late autumn.
• Rhizome fragments establish well in the soil layer down to 5–10 cm, while those buried deeper than 20–25 cm can fail to reach the surface at all.

Favourable conditions

• On fields taken out of cultivation, the couch grass stage of overgrowth can set in after four or more years, depending on the presence of couch grass in the field. This stage can last from seven to 15 years.
• It is more widespread in the forest zone. Most rhizomatous weeds prefer places better supplied with moisture.

Where it is found

In Polissia, it is one of the noxious perennial weeds in maize crops.

Every fact rests on a quote from its source, and each quote was checked against the page it is printed on.

1. EPPO Global Database · European and Mediterranean Plant Protection Organization
2. Приказ № 15-02/584 от 29.06.2015, приложение 1 (пороги вредоносности), казахский текст · Министерство сельского хозяйства Республики Казахстан
3. Прогноз фітосанітарного стану агроценозів України та рекомендації щодо захисту рослин у 2025 році · Держпродспоживслужба, НААН, НАН · p. 234, 243, 256
4. Фітосанітарний прогноз Вінницької області на 2025 рік · ГУ Держпродспоживслужби у Вінницькій області
5. Зуза В. С., «Гербологія», монографія, 468 с. · Харківський державний біотехнологічний університет; Харків: Стиль-Издат, 2022 · p. 15, 45, 46, 47, 51, 109
6. Photos: Javier martin, Wikimedia Commons, Public domain · Matt Lavin from Bozeman, Montana, USA, Wikimedia Commons, CC BY-SA 2.0 · Scott Mills, iNaturalist, CC BY-SA 4.0