Basin Wildrye Research Articles

Effect of Crust Rigidity and Osmotic Potential on Emergence of Six Grass Species1

AbstractNonporous wax crusts were used to compare seedling emergence of tall wheatgrass (Agropyrun elongatum Host), pubescent wheatgrass [Agropyron trichophorum (Link) Richt.], basin wildrye (Elymus cinereus Scribn. and Merr.), Russian wildrye (Elymus junceus Fisch.), tall fescue (Festuca arundinacea Schreb.) and smooth bromegrass (Bromus inermus Leyss.). Seedlings were grown at O, −2.3, −4.4, −6.7, and −8.4 bars osmotic potential under soft, medium, and hard wax crusts, 3 mm thick. The treatments were designed to simulate the separate and combined effects of salty soils and crusts as limiting factors in seedling establishment in arid regions. The germination and emergence phases were separated by using only seeds that germinated as a basis for percent emergence.Emergence of all six species was lower under hard crust than under soft wax crust. Pubescent wheatgrass and smooth bromegrass were most affected by the crust hardness. In the range of osmotic potential used, there was no reduction in emergence as osmotic potential was reduced when the emergence was taken at 2 weeks; however, reduction in osmotic potential did delay emergence. The delay was slightly longer for hard crust than for soft crust.Although osmotic potential did not reduce emergence under soft crusts, a combination of low osmotic potential and hard crust did reduce the emergence of tall wheatgrass, basin wildrye, and Russian wildrye. The emergence of pubescent wheatgrass smooth bromegrass, and tall fescue was reduced principally by the hardness of the crust. Tall fescue was least able to penetrate the crust.The results indicate that osmotic potential may be less important in reducing emergence of field seedlings than is the presence of a crust. In a field situation the slower rate of emergence and low osmotic potential may involve additional crust strength as the soil surface dries.

Cytogenetics of Elymus angustus and Its Hybrids with Elymus giganteus, Elymus cinereus, and Agropyron repens

Five collections of Asian Elymus angustus Trin. were 2n = 84, the highest known chromosome number of any species in the Triticeae tribe. Bivalent pairing predominated at metaphase I; multivalents were formed in less than 5% of the cells, and one or two univalents occurred in almost half of the cells. One hybrid was obtained from 48 emasculated florets of Asian E. giganteus Vahl, 2n = 28, pollinated by E. angustus. The hybrid was 2n = 70 and originated from an unreduced E. giganteus egg and a reduced gamete of E. angustus. The hybrid averaged 8.20I, 28.73II, 1.06III, 0.26IV, and 0.02V in 105 metaphase-I cells. Some irregularity occurred in more than 90% of the cells at all stages of meiosis; yet the hybrid produced 81.1% stainable pollen and averaged 5.3 seeds per spike under open pollination. Unreduced eggs of North American E. cinereus Scribn. & Merr., 2n = 56, were fertilized by reduced E. angustus gametes to give rise to three 98-chromosome hybrids from an unemasculated cross involving two E. cinereus ...

Observations on the Mating System of Basin Wildrye

Observations on the Mating System of Basin Wildrye

Effect of Soil Salinity on Germination and Survival of Some Steppe Plants in Washington

Salt tolerance at germination and the capacity of the established plants to endure gradual salinization of the soil were studied in Agropyron spicatum, Artemesia tridentata, Elymus cinereus (from saline and non—saline habitats), Lepidium perfoliatum (from saline and non—saline habitats), and Typha latifolia. Percentage germination decreased with increasing salinity. All species were less tolerant of salinity at germination than they were at the seedling stage, if salinization of the culture medium was gradual. An abrupt rise in salinity resulted in death of all species. Of all the species tested Lepidium perfoliatum demonstrated the greatest potential for ontogenetic osmoregulation. In general, the response of the established plants corresponds well with the species behavior in the field. Adverse environmental factors, such as a predominance of Na2CO3, probably results in restricted distribution of Typha latifolia and also keeps Agropyron spicatum from colonizing saline areas. Seeds of Lepidium perfoliatum from saline habitats were more tolerant of salinity than those from non—saline habitats, indicating an ecotypic specialization in this species. Populations of Elymus cinereus from saline and non—saline habitats did not differ in this respect.

Encroachment of Big Sagebrush on Seeded Range in Northeastern Nevada

Possibilities for increasing forage production on depleted range lands overgrown with big sagebrush (Artemisia tridentata) have been successfully demonstrated in many places. The proved formula includes brush removal and seeding adapted grasses. The introduced, dought-tolerant wheatgrasses (crested wheatgrass, Agropyron desertorum, formerly known commonly as the Standard variety and now sometimes called desert wheatgrass, and crested wheatgrass, A. cristatum, formerly known commonly as Fairway strain) have been used more than native grasses for this purpose. They are generally better seed producers, easier to establish, and will tolerate as much or more grazing than native bunchgrasses found in the sagebrush zone. The native bunchgrasses have disappeared, wholly or in part, over extensive acres as a result of past heavy grazing, thereby allowing increase of brush. The question arises as to how long crested wheatgrass will persist under grazing, and to what extent it can prevent sagebrush and other undesirable species from reinvading. This paper provides information on these important points from an 825-acre planting in typical sagebrush land in Ruby Valley, Nevada. Prior to treatment of the experimental plots in 1944, big sagebrush averaged 20 plants, 18 to 48 inches in height, plus 60 seedlings, per 100 square feet of Other vegetation in order of abundance included Sandberg bluegrass (Poa secunda), Douglas rabbitbrush (Chrysothamnus viscidiflorus), squirreltail (Sit anion hystrix), tailcup lupine (Lupinus caudatus), hoary phlox (Phlox hoodii canescens), little larkspur (Delphinium andersoni), Indian ricegrass (Oryzopsis hymenoides), arrowleaf balsamroot (Balsamorhiza sagittata), Great Basin wildrye (Elymus cinereus), and trace amounts of a few other species. Grasses occupied only 1 of every 220 square feet of area, or less than one-half of 1 percent of the ground surface. Considering big sagebrush to be 10 percent palatable, the annual grazing capacity was judged to be 40 to 50 animal months for the 82;5 acres, but experienced range man voiced his opinion that one cow would starve on the entire area. One stockman would not risk grazing the area because of larkspur. The area was made available for experimental seeding and demonstrations in 1944 by cooperative agreements between the Intermountain Forest and Range Experiment Station, private ranchers, Bureau of Land Management, and Humboldt National Forest. A major point of interest was to demonstrate on a large scale the feasibility of removing sagebrush and seeding rangeland to provide suitable spring forage for cattle, and thereby relieve early grazing use on certain nearby allotments of the Humboldt Forest. An average annual precipitation of approximately 12 inches and a sandy clay loam soil of average fertility, at an elevation of 5,800 feet, favored success. Treatments and Early Responses