Registration of 'RoadCrest' Crested Wheatgrass
K. H. Asay,
K. B. Jensen, W. H. Horton, D. A. Johnson, N. J. Chatterton, and S. A. Young
'RoadCrest crested wheatgrass (Reg. no.
_________), a rhizomatous cultivar of crested wheatgrass (Agropyron
cristatum (L.) Gaertn.), was developed by a research team at the USDA-ARS
Forage and Range Research Laboratory, Utah State University, Logan, UT, and was
released on 2 June 1998 in cooperation with the Utah Agricultural Experiment
Station. RoadCrest was evaluated as CWG-Rhizome.
RoadCrest was derived from two accessions
originally collected at Dikmen Ankara and GŸvercinlik Ankara, Turkey and
provided to the USDA-ARS Forage and Range Research Unit by Dr. Esvet Acikgoz.
Rhizomatous plants, observed in these accessions during their initial
evaluation on a semiarid range site in central Utah, were selected and
established in a crossing block to develop the parental germplasm. These plant
materials were then subjected to two cycles of selection based largely on
progeny evaluation for increased rhizome development, fine leaf texture, short
growth stature, and improved seedling vigor. Breeder seed was compounded from
selected polycross seedlots in the final breeding cycle.
It is a long-lived perennial, and is
significantly more rhizomatous than any other crested wheatgrass included in
evaluation trials, including the cultivar Ephraim, which is the only other
rhizomatous cultivar of crested wheatgrass to be released. RoadCrest produces
less biomass and is from 15 to 25% shorter in stature than forage-type crested
wheatgrass cultivars. The cultivar has been evaluated on roadsides and in turf
trials in Utah, Colorado, and Washington. Seedling vigor and drought resistance
of RoadCrest compares favorably with other crested wheatgrasses, including
'Hycrest', 'CD-II', 'Fairway', and 'Nordan'. RoadCrest is significantly easier
to establish and initiates growth earlier in the spring than other turf and
low-maintenance turf grasses including Kentucky bluegrass (Poa pratensis),
'Sodar' thickspike wheatgrass (Elymus lanceolatus), tall fescue (Festuca
arundinacea), and hard fescue (Festuca ovina). Leaf color
intensity and turf quality of RoadCrest are not as good as Kentucky bluegrass,
tall fescue, and perennial ryegrass when the latter grasses are grown under
optimum conditions. RoadCrest greens up early in the spring and remains green
until mid summer on temperate sites similar to Logan, Utah. Plants then go
dormant until temperatures decline in the fall. This characteristic varies
according to summer temperatures and annual precipitation. Summer dormancy is
much less prominent at elevations above 1,500 m.
RoadCrest is recommended for use along
roadsides or similar low-maintenance turf applications in temperate, semiarid
regions receiving from 250 to 500 mm of annual precipitation. Seeding rates
should be from 17 to 28 kg ha-1, which is substantially less than
those recommended for other turf grasses such as Kentucky bluegrass, ryegrass,
or tall fescue. When seeded at more than the recommended rate, particularly at
high moisture levels, seedling diseases are likely to occur resulting in
substantial thinning of the stand. However, the remaining seedlings of
RoadCrest readily establish, and excellent stands are usually obtained. As with
other crested wheatgrass cultivars, supplemental irrigation can actually be a
detriment if total water application (precipitation + irrigation) exceeds 550
mm annually.
RoadCrest is a natural tetraploid (2n=4x=28)
and is fully interfertile with tetraploid cultivars of crested wheatgrass (Agropyron
cristatum and A. desertorum), Siberian crested wheatgrass (A.
fragile), and the crested wheatgrass hybrid cultivars Hycrest and CD-II.
Established isolation distances from these cultivars must be maintained in
Certified seed fields. The cultivar produced 560 kg of seed ha-1
when grown in rows 0.9 m apart with moderate supplemental irrigation and 50 kg
N ha-1 applied in the fall. At 100% percent purity, there are
approximately 530,000 seeds kg-1.
Breeder, Foundation, and Certified seed
classes will be recognized. Breeder seed will be maintained by the USDA-ARS
Forage and Range Research Laboratory at Logan, UT. Foundation seed will be
produced by the USDA-ARS at Logan and distributed by the Utah Crop Improvement
Association. Rights for production and marketing of Certified seed will be
awarded on a bid basis. Protection will be applied for under the Plant Variety
Protection Act of 1994. Conditions of this license specify that seed of the
cultivar RoadCrest can be marketed only as a class of Certified seed. Genetic
material of this release will be deposited in the National Plant Germplasm
System where it will be available for research purposes, including development
and commercialization of new cultivars.
References