CWMA

PO Box 419

Hotchkiss, CO 81419

 

970-361-8262

fax: 720-880-3051


Email:contact@cwma.org

 

 

Jointed Goatgrass

Aegilops cylindrica

 

Key Characteristics

  • Annual grass
  • 15-30 inches tall

This information courtesy of the Colorado Natural Areas Program

 

Family: Grass (Poaceae)

 

Other Names: Goatgrass

 

USDA Code: AECY

 

Legal Status: Colorado Noxious Weed List B

 

 

Identification

Lifecycle: Annual

 

Growth form: Grass

 

Flower: The seed head is 2-4 in long with 5-10 spikelets (joints) per head. Early to mid-June.

 

Seeds/Fruit: Spikelets are 0.5 in long with 1-3 viable seeds. At maturity spikelets separate with a segment of the stems still attached.

 

Leaves: Leaves are alternate, simple, with a flap-like appendage (auricle) at the base, and a leaf blade 0.17-0.25 in wide, with hairs.

 

Stems: Mature plants are generally 15-30 in tall with one to many tillers.

 

Roots: Short fibrous root system

 

 

Similar Species

Exotics: Similar in appearance, and genetically related to, winter wheat

 

Natives: N/A

 

 

Impacts

Agricultural: Jointed goatgrass has become a very serious weed in winter wheat and other cereal crops. Its genetic similarity, and similar growth characteristics to winter wheat make it very difficult to control without adversely harming crop production. Jointed goatgrass also infests rangeland surrounding wheat growing areas and land in the Conservation Reserve Program throughout the western United States.

 

 

Habitat and Distribution

General requirements: It can flourish in areas of 10-20 in annual rainfall.

 

Distribution: Jointed goatgrass is found throughout the western United States at elevations up to 6,000 ft.

 

Historical: Jointed goatgrass is thought to have been introduced from Turkey in contaminated wheat.

 

 

Biology/ Ecology

Life cycle: Jointed goatgrass flowers in early to mid-June. Some jointed goatgrass seeds germinate early and the remainder of the seeds may persist in the soil for years. Jointed goatgrass seeds usually germinate from early August - October but they can also germinate in late spring and still mature if temperatures are low enough.

 

Mode of reproduction: Seed

 

Seed production: A jointed goatgrass plant can produce up to 100 spikes, 1,500 spikelets and up to 3,000 seeds.

 

Seed bank: Soil moisture plays an important role in jointed goatgrass seed viability and dormancy. Regardless of conditions, jointed goatgrass seeds rarely remained viable for over five years in the soil.

 

 

Integrated Management Summary

Studies have shown that jointed goatgrass, winter wheat, and downy brome all compete for nutrients, moisture, and light. Comparatively, winter wheat is usually more competitive than jointed goatgrass, and both are much more competitive than downy brome. Jointed goatgrass also has a faster growth rate than downy brome. This faster growth rate, plus the use of herbicides that are more effective controlling downy brome than jointed goatgrass, may result in a weed species shift from downy brome to jointed goatgrass. An integrated management strategy should focus on preventing the establishment of new infestations in suceptible areas, and depleting the soil seed bank.

 

 

References

Lyon, D.J. 1998. Jointed Goatgrass Biology. Internet 07/28/98. www.ianr.unl.edu/jgg/billings/lyonbiol.htm

 

Morishita, D.W. 1998. Biology of Jointed Goatgrass. Internet 07/28/98. www.ianr.unl.edu/jgg/conf/morish2.htm

 

Stahlman, P.W. 1998. Jointed Goatgrass Control Methods – A Review. Internet 11/12/98. www.ianr.unl.edu/jgg/stahlman.htm

 

Whitson, T.D.(ed.), L.C. Burrill, S.A. Dewey, D.W. Cudney, B.E. Nelson, R.D. Lee, R. Parker. 1996. Jointed goatgrass. Weeds of the West. Western Society of Weed Science, in cooperation with the Western United States Land Grant Universities Cooperative Extension Services, Newark CA . pg. 408.

 

Back to Weed List