REGISTRATION OF 'HYCREST' CRESTED WHEATGRASS
Crop Sci. 25: 368-369 (1985)
K. H. Asay,
D. R. Dewey, F. B. Gomm, D. A. Johnson and J. R. Carlson
Hycrest' (Reg. no. 16) was released by the
USDA-Agricultural Research Service in cooperation with the Utah Agricultural
Experiment Station and the USDA-Soil Conservation Service on 18 April 1984.
The parental germplasm was generated by
crossing induced tetraploid Agropyron cristatum (L.) Gaertn. with natural
tetraploid A. desertorum (Fisch. ex Link) Schult. Initial crosses were made
between 1962 and 1967(1). The genetic base of the hybrid population was
established with seven clones each of induced tetraploid A. cristatum and A.
desertorum. Reciprocal crosses were made to insure that cytoplasms of both
species were represented in the breeding population.
In 1974, open pollination progenies of 295 F3
hybrid clones were established in a 7,000-plant source nursery on a range site
in northwest Utah. After a 2-year evaluation period, 103 clones were selected
on the basis of general vigor, leafiness, resistance to insects and diseases,
and seed yield potential. Selected clones and their OP progenies were included
in replicated tests at two field locations where they were evaluated for seed
and forage yield, seedling vigor, and other characteristics previously studied
in the source nurseries. On the basis of these data, 18 clone were isolated in
a crossing block to develop the first generation of the synthetic strain.
Hycrest, the first interspecific hybrid of
crested wheatgrass to be released, tends to be larger and more robust than the
two parental species. In trials on five range sites in Utah and Idaho, it
established better stands and produced significantly more forage than 'Nordan'
or 'Fairway', particularly during the first 2 years after seeding. In
spaced-plant trials, the hybrid produced about 20% more seed than Nordan and
Fairway. Hycrest also established significantly better than the cultivars
Fairway and Nordan in the field and showed superior root development, emergence
from deep plantings, and subsequent seedling vigor in the laboratory.
Preliminary observations indicated that its forage is as palatable to grazing
cattle during the mid-summer as presently available cultivars. Although the
cultivar is well adapted to sagebrush (Artemisia spp.) and juniper (Juniperus
spp.) vegetation sites, it also established good to excellent stands on
shadscale [Atriplex confertifolia (Torr. & Frem.) S. Wats], greasewood
[Sarcobatus vermiculatus (Hook.) Torr.], and Indian ricegrass [Sorghastrum
nutans (L.) Nash] sites where annual precipitation is less than 25 cm. At 100%
purity, there were 335,000 seeds kg-1. Recommended seeding rate for
seed production is 2.5 kg ha-1 in rows approximately 1 m apart. When
drilling on rangeland, 7 kg ha-1 is recommended.
Breeder, foundation, and certified seed
classes will be recognized. Breeder seed will be maintained by the USDA-ARS
Crops Research Laboratory at Logan, UT. Foundation seed will be produced from
breeder's seed by the USDA-SCS. For information regarding supplies of
Foundation seed, contact local soil conservation districts and crop improvement
associations of the state where the seed is to be planted.
References
1. Dewey, D. R., and P. C. Pendse. 1968.
Hybrids between Agropyron desertorum and induced-tetraploid Agropyron
cristatum. Crop Sci. 8:607-611.