Russian wildrye regenerated well following a late August wildfire that burned
through the Aberdeen plant materials testing fields in southeast Idaho.
The fire burned rapidly through the test plots, and Russian wildrye had started
to green up by October of the same year. By July of the following
year, the Russian wildrye plots were all green and plants averaged 8 inches
(20.6 cm) tall [144].
Russian wildrye was favored by a spring burn of a cultivated field near Fargo, North Dakota.
Canopy coverage of Russian wildrye was higher on the burned areas in the second postburn season (13%) than on
the unburned areas (10.5%) [113].
This description provides characteristics that may be relevant to fire ecology,
and is not meant for identification. Several florae provide keys for identifying
Russian wildrye [45,46,59,61,162,163,164].
Russian wildrye is a nonnative, perennial, cool-season, bunch-type grass
[136]. It is long lived and resistant to cold and drought
[8]. Wasser [161] estimates longevity to be 25
years or longer in cultivated plots in the Northern Great Plains and somewhat
shorter on sites within the Great Basin.
The culms of Russian wildrye are leafless, erect and densely tufted,
typically 1.3 to 3.7 feet (0.4-1.1 m) tall. The inflorescence is a terminal
spike, 1.2 to 4.3 inches (3-11 cm) long. Glumes and lemmas are typically
scabrous and short-awned. The fruit is a caryopsis, 0.2 inch (5 mm) long. Leaves
are basal, 3 to 11 inches (7-30 cm) long and 0.25 to 0.5 inch (6.4-12.8 mm) wide with blades that are flat or curled
inward [61,164]. Leaf sheath bases are usually persistent, often
shredding into fibers [36]. Russian wildrye
forms an extensive network of dense, fibrous roots and is strictly caespitose,
forming no rhizomes or stolons [26,35,59,107]. The root system can establish
to a depth of 8 to 10 feet (2.5-3 m), with 75% of roots in the top 6 inches (15
cm). The horizontal spread of the root system can be 4 to 5 feet (1.2-1.5 m) [142].
Physiology:
Flooding —
Russian wildrye has moderate flood tolerance in the summer and fall [122], but is intolerant of
winter or spring flooding [142].
Drought—
Russian wildrye is exceptionally tolerant of
drought [82,142]. Russian wildrye produces seminal lateral roots when
drought kills the primary roots [15,53,149]. Plants may survive for 60 days or more when restricted to only the seminal root
system until moisture conditions improve and adventitious roots develop [15].
State
ElevationThere has been some concern expressed in the literature about using nonnatives
for revegetating disturbed areas or improving rangeland forage. Monsen
and McArthur [108] suggest that the use of nonnatives has been so successful on
some sites that their longevity, adaptation, and competitive ability have made
it difficult for native plants to recover or reestablish. Koehler [88]
cautions that seeding efforts that involve the destruction of valuable wildlife
browse, especially in key wintering areas, should not be attempted. He
further suggests that seeding with nonnatives should only be done on an
"emergency" basis in areas in particularly critical condition.
Dormaar and others [44] compared native rangeland to 17- to 27-year-old
cultivated monocultures of Russian wildrye in southern Canada. The native range
had about 7.5 times more root mass in the upper soil horizons, and soils in the
native rangeland had significantly more (P<0.01) organic matter. The wide spacing
used for the seeding of the Russian wildrye resulted in 44% bare ground
exposure, compared to less than 5% for the native range.
As of this writing (2005), Russian wildrye is apparently not considered invasive or noxious.
The biggest limitation in growing Russian wildrye is the difficulty of establishment.
Seeding depth is the most crucial factor determining successful establishment. Seed establishment is
enhanced by seeding into a firm, weed-free seedbed at a
depth of less than 1 inch (2.5 cm). Seeding can be done in early spring,
in summer if soil moisture is adequate, or in late fall once soil temperatures
remain below 45 oF (4.4 oC). Row spacings of
2 to 3 feet (0.7-0.9 m) are recommended for pastures in dry areas, and 1 to 2
feet (0.3-0.7 m) in areas where the annual precipitation is above 14 inches
(35.6 cm) [70,154].
Although Russian wildrye will produce seed well on relatively fertile dryland
soils, seeds are difficult to harvest due to lodging and shattering [136]. The relatively high
moisture content and softness of the
seed can lead to damage during harvesting and reduced germination potential. Seeds should be
harvested in the firm dough stage with a combine set at a slow
cylinder speed (1,000 rpm). Seeds harvested in this stage will need to
be dried before storage [154]. Binding and field curing is an alternative
method of seed harvest [12,31,154]. Nitrogen fertilization is necessary to maintain high
seed yields of Russian wildrye for many years [154].
Russian wildrye is subject to attack by grasshoppers and cutworms [141], but is relatively
resistant to the bluegrass billbug [7,112]. Russian wildrye is resistant to barley-yellow-dwarf
virus [110], but is susceptible to Septoria leaf spot disease
[18] and head smut [150].
Russian wildrye reproduces by seeds and by tillering [39,65,164].
Breeding system:
Russian wildrye is monoecious [61].
Pollination:
A reference could not be found that speaks specifically to the pollination of Russian wildrye, but
it is presumed that it is similar to other perennial grasses
and is cross-pollinated by wind [58,68,153].
Seed production:
Seed production in Russian wildrye ranges from 50 to 300 pounds per acre under
dryland conditions [17,136] and 100 to 700 pounds per acre with irrigation
[12,95,136]. Grazing soon after seed maturity increases the seed production the following year by
preventing the development of long mesocotyls. Long mesocotyls cause the shoot
apices to form in an elevated position where they are more exposed to frost
damage, resulting in a loss of seed production potential [96].
Seed dispersal:
The seed of Russian wildrye shatters readily at maturity [142]. Most of the seed falls under
or near the parent plant [50].
Seed banking: Grasses
typically have seeds that are a transient part of the seed bank. Much of
the seed remains in the litter layer and is lost to predation [105].
Germination:
In the laboratory, Russian wildrye
germinates at a rate of 82% to 85% at 62 to 86 oF (17-30 oC)
[11,136,176]. Germination rate drops to
34% at colder temperatures and to 70% at warmer temperatures [176]. Maximum germination rate is
achieved at 14 days. Shaw and Cooper [136]
recommend 5 days of prechilling prior to planting for optimum seed germination. Seeds can be
stored for 4 years before germination rates fall below 70% [136]. Germination rates decrease with increased moisture
stress. In laboratory tests, seed germination was greater than 90% at a
simulated dehydration level of -59 megapascals (mP). The germination rate
dropped to an average of 60% at -120 mP and 33% at -220 mP [14].
Seedling establishment/growth:
Russian wildrye is very difficult to establish. It is especially sensitive
to seeding depth, and does not emerge well if seeded to a depth of greater than
0.5 to 0.75 inch (1.3-1.9 cm) [6]. Seedlings are weak and develop slowly
[142]. Seedling establishment is best on loamy soils
because sandy soils may dry out before seedling roots can grow to a depth to
find available moisture [72].
Asexual regeneration:
Russian wildrye produces tillers from axillary buds on the root crown [65].
Heavy grazing can decrease tiller numbers, but moderate
grazing to a plant height of 3 inches (7.6 cm) can
stimulate tillering and increase tiller numbers [39,65]. Although Russian wildrye does produce
tillers, the vegetative spread is very slow [12].
Russian wildrye is rated as having medium shade tolerance. It does best
when exposed to full sunlight, but is not especially sensitive to shading [136].
When seeded on mountain-brush sites in Utah, Russian
wildrye was more productive growing in the light shade of greasewood (Sarcobatus
spp.), big sagebrush (Artemisia tridentata), and rubber rabbitbrush (Chrysothamnus
spp.) than on sites lacking those woody species [124].
Although Russian wildrye is hard to establish and slow to spread, once it is
established, the extensive root growth makes this grass very competitive for
water and nutrients [26,136,142]. When established in pure stands, it may
nearly exclude other vegetation for years
[72,82].
Plummer [125] suggests that Russian wildrye planted into salt desert shrub
areas seldom persists longer than 10-12 years and is replaced eventually by
natives or more invasive introduced grasses. On a salt desert shrub site
in Utah, Russian wildrye persisted for more than 14 years at a cover of 15% to
21%; natural recruitment of native species including shadscale (Atriplex
spp.), green molly (Kochia americana), and bottlebrush squirreltail (Elymus
elymoides) increased on the plots within this time period [111]. In the arid shadscale zone of Utah
and Nevada, Russian wildrye was still surviving on some sites after 10 years,
although coverage was considered "sparse" [24].
In pinyon-juniper woodlands on the Hualapai Indian Reservation in Arizona,
Russian wildrye persisted on seeded sites for more than 21
years [41].
In aspen (Populus spp.) parkland pastures in British
Columbia, Russian wildrye established well, but was replaced steadily by crested
wheatgrass (Agropyron cristatum), smooth brome (Bromus inermis)
and Kentucky bluegrass (Poa pratensis) until it was considered "all but
gone" within 10 years [103,158].
Russian wildrye planted into a big sagebrush habitat in Nevada persisted for at least
18 years. It persisted best for the
first 11 years, and then was steadily replaced by the sagebrush [130].
In Alberta rangelands, cultivated fields of Russian wildrye have persisted
for 17 to 35 years; native grasses generally did not reinvade the fields [140].
Russian wildrye has been used extensively to revegetate burned areas [1,27,41,111]. Reseeding
after fire with Russian wildrye often provided quick cover and reduced the
invasion of nondesirable invasives, such as cheatgrass (Bromus tectorum),
while providing for good livestock forage [111]. Plantings
of Russian wildrye have generally been most successful when planted in
pure stands and when Russian wildrye was drill-seeded, as opposed to broadcast or aerially
seeded [74,111,115]. Lavin [94] suggested that Russian wildrye may be
a good species to use when the revegetation goal is the recovery of ponderosa pine
(Pinus ponderosa) seedlings; the
bunch type growth of the grass will provide quick soil cover, but still permit the survival of
the tree seedlings [94].
Russian wildrye has been commonly and effectively used in revegetation efforts
to control invasive nonnatives including leafy spurge (Euphorbia
esula), spotted knapweed (Centaurea maculosa), diffuse knapweed
(C. diffusa), Russian knapweed (C. repens), yellow starthistle (C.
solstitialis), cheatgrass, halogeton (Halogeton glomeratus),
Dalmatian toadflax (Linaria dalmatica), Canada thistle (Cirsium
arvense), and musk thistle (Carduus nutans). Herbicide
application, with or without cultivation, prior to seeding with Russian wildrye
often improves the level of weed control [20,21,25,26,32,40,42,50,91,92,100,126,131,167,168,169,170].
Although Russian wildrye has been planted for erosion control, it is not
especially suited for this purpose. When planted in pure stands, it does
not naturally fill in between rows very quickly after planting [37,44,140,141]. A high percentage of bare ground
is left exposed, increasing the risk of wind and water erosion [171]. However,
in critical situations, planting Russian wildrye provides quick cover, giving
better erosion control than no vegetation cover at all [87,94].
Attempts to use Russian wildrye to revegetate mine spoils have generally not
been successful [49,104,109].
Psathyrostachys juncea is a species of grass known by the common name Russian wildrye. It was formerly classified as Elymus junceus. It is native to Russia and China, and has been introduced to other parts of the world, such as Canada and the United States.[1] Psathyrostachys juncea is a great source of food for grazing animals, as it has high nutrition value in its dense basal leaves, even in the late summer and autumn seasons. This species can grow and prosper in many harsh environments, making it an ideal candidate for improvement as it can grow in areas were farming is difficult. This species is a drought-resistant forage plant and can survive during the cool seasons. It is also a cross-pollinator and is self-sterile.[2] This means that P. juncea cannot self-fertilize; it must find another plant of the same species with which to exchange gametes. Self-sterilization increases the genetic diversity of a species.
Psathyrostachys juncea is a perennial bunch grass that grows in tufts that may be up to 1 metre (3.3 ft) tall or taller. The grass is long-lived and known to persist in cultivation for 25 years or more.
The grass has a dense root network beneath each clump; there are no rhizomes or stolons. The roots can reach 3 metres (9.8 ft) deep into the soil.
The leaves are located around the stem bases, and are straight or curled. Old leaf sheaths become shreddy. The inflorescence is a spike up to 11 to 16 centimetres (4.3 to 6.3 in) long.[1][3]
Many cultivars of Psathyrostachys juncea have been developed, including 'Vinall', 'Bozoisky-Select', and 'Bozoisky II'.[1]
Though Psathyrostachys juncea can survive in harsh conditions, it is a hard species to initially plant, because the seeds must be in the correct conditions in order to begin germination.[4] Psathyrostachys juncea has low seedling vigor, which affects the success of germination. But once P. juncea has begun germination, it can tolerate most harsh weather conditions. In recent years, scientists have explored possible solutions to improving seedling vigor. One possible technique to increasing seedling vigor is increasing ploidy.[5] In nature, P. juncea are diploids, however, tetraploid germplasm have been show to increase seed size and seedling vigor in P. juncea.[4] Regeneration of this species has been successful, meaning that scientists can more easily select for specific traits and manipulate P. juncea at the cellular level.[2] Thus, humans can easily induce tetraploidy in P. juncea. As a result, breeding programs have begun to grow tetraploid cultivars so as to increase the success of P. juncea germination. There is a small change in tissue quality and nutrition content with different ploidy levels, but nothing significant. Therefore, increasing tetraploid cultivars is a possible avenue for improving seed quality. Path analysis has been conducted to examine what exactly effects seed yield. Fertile, strong stems (tillers), the number of flowers (florets) per flower cluster (spikelet), and seed weight all showed positive relationships with seed yield.[6] That is, P. juncea with more stems/tillers, more flowers, and/or heavier seeds have improved seed yield. However, the number of flower clusters (spikelet) per stem and number of seeds per flower cluster were negatively correlated with seed yield. Thus, having more flowers on a cluster, not more seeds per cluster, increasing seed yield.[5] This information can be used to improve breeding programs for P. juncea. In addition, water stress also improves leaf and inflorescence tissue quality, while nitrogen rich fertilizer improves leaf, stem, and inflorescence tissue quality. Increased tissue quality is related to improvements in total yield.[5]
Psathyrostachys juncea was introduced to North America as a forage grass and for rangeland rehabilitation and soil stabilization. The grass is "one of the most versatile forage grasses available for dryland pastures."[7] It is palatable to livestock, though it does not make a good hay due to its basal leaves. It is also palatable for wild ungulates, such as elk. The grass is a particularly good forage when planted in alternating rows with a legume, such as alfalfa.[7]
It is not generally invasive and usually does not become a noxious weed. It rarely grows outside of plots where it has been planted. The Southwestern United States has some invasive occurrences, such as on the Grand Canyon plateaus.
It is drought-resistant, flood-resistant most of the year, and is tolerant of cold. It is also tolerant of high soil salinity.
It is not easy to establish via seed; if the seeds are planted more than 1.9 centimeters deep the seedlings do not emerge in large numbers. The seedlings are weak. Once it has established, however, it is tough and competes well for water and nutrients. It is tolerant of fire because the dense clumpiness of the stems protects the axillary buds, which can produce tillers and resprout after destruction by fire.[1]
There are four novel alleles coding for high molecular weight glutenin subunits (HMW-GS) in the genus Psathyrostachys. High molecular weight glutenin subunits provide protein to the endosperm in wheat relatives but also determine the level of wheat improvement possible in a plant species. These proteins are coded from the Gun-1 locus, and studying this locus has helped scientists trace the evolutionary ties between Triticeae species. This means that P. juncea has close evolutionary ties to wild wheat relatives.[8] Wheat improvement is therefore a major possibility for P. juncea. By improving wheat quality, P. juncea could potentially become a crop for human consumption, especially in areas were growing crops is challenging such as in dry or drought areas. The current obstacle to wheat improvement is that cross-pollinating wheat and P. juncea is extremely difficult because their gametes are not compatible with each other.[9]
Psathyrostachys juncea is a species of grass known by the common name Russian wildrye. It was formerly classified as Elymus junceus. It is native to Russia and China, and has been introduced to other parts of the world, such as Canada and the United States. Psathyrostachys juncea is a great source of food for grazing animals, as it has high nutrition value in its dense basal leaves, even in the late summer and autumn seasons. This species can grow and prosper in many harsh environments, making it an ideal candidate for improvement as it can grow in areas were farming is difficult. This species is a drought-resistant forage plant and can survive during the cool seasons. It is also a cross-pollinator and is self-sterile. This means that P. juncea cannot self-fertilize; it must find another plant of the same species with which to exchange gametes. Self-sterilization increases the genetic diversity of a species.
