Biology and Impacts of cheatgrass(Bromus tectorum), foxtail barley(Hordeum jubatum), and bulbous

bluegrass (Poa bulbosa)

Brian Sebade

University of Wyoming Extension

Extension Educator for Northeast Wyoming

What is a weed?

A weed is...

• Plants that are competitive, persistent, andpernicious and therefore interfere with humanpernicious and therefore interfere with humanactivities

–Stephen Miller

General Biology of Bromus tectorum L.

• Common names: downy brome, cheatgrass, cheat

• Introduced from the Mediterranean area of Europe

• Believed to have reached the United States in the late1800’s via packaging material

• Historically was used extensively for thatching roofs in• Historically was used extensively for thatching roofs inthe Mediterranean region

• Cheatgrass has the ability to establish quickly ongrowing sites that are undesirable to other species

• Has made immediate and major impacts since itsintroduction

Biology continued

• Winter annual growth pattern

• Grows 4-24 inches tall in high plant densities

• Prefers well drained soils of most textures

• Not well adapted to saline or sodic soils• Not well adapted to saline or sodic soils

• Usually greens up before most native plantspecies in the early spring

• Mature plants often turn a purplish color

• Large amounts of seeds are produced and arenotorious for sticking to objects

http://plants.usda.gov/gallery/standard/brte_010_shp.jpg

Cheatgrass Impacts

• Grazing potential affected

• Increased fire potential

• Loss of desired species

• Loss of desired function and structure of sites• Loss of desired function and structure of sites

• Crop yield decreases

• Soil nutrient changes

• Resources for control

• Others?

• Positive impacts?

http://plants.usda.gov/gallery/standard/brte_009_shp.jpg

Biology of foxtail barley

• Cool perennial growth pattern

• Reproduces mainly via seeds

• Seeds that can easily be dispersed

• Height 1-2 feet tall• Height 1-2 feet tall

• Adapted to wet soils

• Enjoys alkaline soils

• Native to North America

• Squirreltail is a similar specieshttp://plants.usda.gov/gallery/standard/hoju_008_shp.jpg

http://plants.usda.gov/gallery/standard/hoju_002_svp.jpg

Foxtail Barley Impacts

• Decreased grazing potential• Removal of desired species (i.e. monoculture

stands)• Loss of site function and structure• Decreased crop yields• Decreased crop yields• Harmful to livestock (injuries to eye, mouth and

throats of grazing animals)• Resources for control• Others?• Benefits?

Bulbous Bluegrass Biology

• Cool season perennial grass• Introduced from Europe• Grows from basal bulbs (only grass known to

grow from true bulbs)• Grows to a height of 6-24 inches tall• Grows to a height of 6-24 inches tall• Thought to reproduces asexually when

introduced, yet sexual when growing in nativeregions

• Most likely because of different growingconditions

Biology continued

• Grows in most temperate and subtropical regions

• Generally speaking bulbous bluegrass enjoys mildwinters, dry summer, and winter rain

• Can be found in many sites, if the site receives12-40 inches of precipitation

• Can be found in many sites, if the site receives12-40 inches of precipitation

• Adapted to a variety of soils textures andcharacteristics

• Attempts have been made to cultivate the grassas a turf species

Sheri Hagwood @ USDA-NRCS PLANTS Database

http://extension.umass.edu/landscape/sites/landscape/files/weeds/culms/poabu4839w.jpg

Bulbous Bluegrass Impacts

• Decreased crop yields

• Decreased structure and function

• Loss of desirable species• Loss of desirable species

• Resources for control

• Others?

• Benefits?

Biology Overview

• All three species considered weeds and exhibitweedy traits

• All three species are adapted to a wide range ofsoil types, textures, and precipitation regimes

• All three are able to quickly spread and occupy• All three are able to quickly spread and occupyundesirable and desirable growing locations

• Cool season growing patterns are used by allthree species

• Cheatgrass is an annual whereas bulbousbluegrass and foxtail barley are perennials

• Each species has a certain niche it uses tomaintain large populations in certain areas

Impacts Overview

• All three species to some extent impactgrazing by livestock

• All three have the ability to affect thestructure and function of a sitestructure and function of a site

• All three can decrease amount of desiredplant species

• All three can negatively impact cropproduction

• All three usually require monetary, time, orenergy for control when not desired

Structure and Function

• Native plant community structure and functionare negatively impacted with these processes:

Nutrient cycling

Fire regimesFire regimes

Water cycling

Different size and structure of plant community(new structure of plant community mightbecome less desirable for certain wildlife species)

Positive impacts• All three provide limited grazing opportunities

depending on livestock species and timing ofgrazing

• Some wildlife species might benefit formthese species (example chuckers andthese species (example chuckers andcheatgrass)

Take Home Message

• One of these species can be found in almostany region of Northeast Wyoming

• Different management strategies might beneeded for control of each species evenneeded for control of each species eventhough all three species exhibit weedy traits

• All three species exhibit slightly differentgrowth patterns (annual, perennial) anddesired growing regimes (temperature, soil,water)

Questions

http://plants.usda.gov/gallery/standard/hoju_008_shp.jpg http://plants.usda.gov/gallery/standard/brte_010_shp.jpg

http://extension.umass.edu/landscape/sites/landscape/files/weeds/culms/poabu4839w.jpg