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Garnet Mountain Bromegrass Long Range Field Planting Plan

Plant Accession Data

  • accession: 9005308
  • common name: mountain bromegrass
  • scientific name: Bromus marginatus Nees ex Steud

Description

Mountain bromegrass is a native, short-lived perennial, bunchgrass indigenous to open meadows and disturbed sites in mountains and foothills of the northern and central Rocky Mountains, Intermountain Region, and Pacific Coast. It is a medium sized, cool-season grass with shallow, fibrous roots and culms reaching 30 to 120 centimeters high. The wide, flat leaves are both basal and cauline. The inflorescence is an open, rather narrow panicle with strongly keeled spikelets. The lemmas are soft-hairy on the back with a short (5 to 7 millimeter) terminal awn. The leaf sheaths have a closed collar and are sparsely hairy.

Origin

9005308 mountain bromegrass was collected in Powell County, Montana, near the ghost town of Garnet (elevation 1,770 meters.)This collection was first evaluated in Montana - along with 23 other mountain bromes and "Bromar" in an Evaluation Planting (IEP) at the State Forest Tree Nursery, Missoula, Montana, in October 1983. 9005308 exhibited better overall plant vigor and maintained stands longer than Bromar. At the Upper Colorado Environmental Plant Center in Meeker, Colorado, IEPs were established in 1980 and in 1984 comparing Bromar and 9005308 with 65 and 55 mountain brome collections, respectively. Although Bromar was one of the easiest accessions to establish, 9005308 had better stand longevity and excellent head smut resistance.

Adaptation

Mountain bromegrass prefers deep, fertile, and mesic soils of medium to fine texture. It can survive on thin, dry, or coarse soils, but at a reduced  level of production. It grows predominantly in areas receiving 380 to 480 millimeters of mean annual precipitation and at elevations up to 3,000 meters. Mountain bromegrass grows throughout the mountain areas of the Pacific Northwest, thriving in climates with cool, dry summers and good winter precipitation. This grass does not tolerate a high water table or flooding, but has good tolerance of shade, fair tolerance of fire, and is very winter hardy. This species has excellent seedling vigor and establishes quickly, often producing seed the year of esrablishment. Stands of mountain brome depend on natural reseeding for its self perpetuation.

Establishment

Seed should be planted into a firm, weed-free seedbed at a depth of 1 centimeter. In most plantings mountain brome will be included in a mixture with other grasses, forbs, and shrubs. There are approximately 176,000 mountain brome seeds per kilogram, requiring a pure stand seeding rate of 12 pure live seeds (pls) kilograms per hectare. The seeding rate should be adjusted accordingly when included as a component of a mixture. Seed should be drilled in late fall (dormant) or early spring.

Uses

Mountain bromegrass is usually found as a component of native grass/shrub/forest plant communities - often in disturbed soil related to rodent activity, erosion, or man-made disturbances. This species is commonly included in seed mixtures for reclamation of drastically disturbed lands, reseeding following wildfires, and for reforestation of native plant communities. It is a quick establishing species which provides initial soil stabilization when planted with other slower establishing natives. As slowe developing species become established, the stands of the short-lived mountain brome will slowly decline. Mountain bromegrass is considered a decreaser species in the range sites it occupies. It is commonly found in the following Major Land Resource Areas (MLRAs): Northern Rocky Mountains and Valleys (44 and 43), Northern Rocky Mountain Foothills (46), Wasatch and Uinta Mountains (47), Southern Rocky Mountains Parks (48B), and Southern Rocky Mountain Foothills (49).

Management

Like most cool season grasses, mountain brome initiates growth in early spring with seed maturity by late July or early August. With good soil moisture conditions, this grass will develop late summer or fall regrowth. Only a moderate response to fertilization can be expected. Weed control (mowing and/or chemical control) may be necessary the establishment year. Mountain brome has good palatability for all classes of livestock and wildlife in the early spring. At maturity the stems and leaves become rough and coarse, resulting in lower palatability; however, at this stage the nutritious seedheads are relished by all grazing animals. With new plantings of mountain brome, grazing should be deferred until the stand becomes established, then rotational grazing should be practiced.

Seed Production

Seed of mountain bromegrass is relatively easy to produce. The large, abundant seed can be directly combined if the stand ripens uniformly, but it is commonly swathed at the firm dough state and combined out of the windrow. Under ideal conditions, some seed may be produced the seedling year. However, only one or two good seed crops can be harvested before the stands begin to deteriorate. Seed production is usually done under irrigation or in areas receiving 400 millimeters of mean annual precipitation. Seed, if not infested with head smut, can yield as high as 1,000 kilograms per hectare under irrigation. Mountain brome seed should be treated with a labeled fungicide to reduce the incidence of head smut. 9005308 mountain brome has exhibited a high level of resistance of head smut. The large seed of mountain brome is easily conditioned with conventional seed cleaning equipment.

Planting Information

Culture and Management 1

In accordance with applicable practice standards and specifications as stated in Section IV of the Field Office Technical Guide.

Field Planting Size

Minimum five (5) acres each, featured cultivar and standard of comparison entry.

Seeding Rate

Mountain bromegrass has approximately 80,000 seeds per pound. One (1) pound pure live seed (PLS) per acre in native species mixtures is recommended. Adjust rate accordingly for specific mixture objectives.

Standard of Comparison
  • 'Sherman" big bluegrass
  • 'Bromar' mountain bromegrass
  • 'Pryor' slender wheatgrass
  • Perennial ryegrass
Evaluation

Herbaceous plant performance will be requested annually for the first five (5) years and the tenth (10th) year following establishment. Use standard evaluation forms.

1 Seedbed preparation, planting methods, seed placement depth, weed control, and stand establishment management..

2 Field office location managed by the respective Natural resource Team.

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Last Modified: 07/05/2007