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Articles 1 - 8 of 8

Full-Text Articles in Plant Sciences

Sand Bluestem And Prairie Sandreed Establishment, Robert A. Masters, Kenneth P. Vogel, Patrick E. Reece, Dennis Bauer Nov 1990

Sand Bluestem And Prairie Sandreed Establishment, Robert A. Masters, Kenneth P. Vogel, Patrick E. Reece, Dennis Bauer

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Sand bluestem [Andropogon gerardii var. paucipilus (Nash) Fern,] and prairie sandreed (Calamovitfa longifolia Hook.) are native warm-season grasses used to revegetate cropland and degraded rangeland on highly erodible sandy soils in the central Great Plains. The objectives of this study were to compare establishment success of the 2 grasses and to determine if application of atrazine at time of planting enhanced grass establishment. Eight plantings, including 'Goldstrike' and 'Garden' sand bluestem and 'Goshen' and 'Pronghorn' prairie sandreed, were made from 1985 to 1987 at locations in eastern, north central, and western Nebraska. Three plantings were established under irrigation …


Ermelo Weeping Lovegrass Response To Clipping, Fertilization, And Watering, Robert A. Masters, Carlton Britton Sep 1990

Ermelo Weeping Lovegrass Response To Clipping, Fertilization, And Watering, Robert A. Masters, Carlton Britton

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

A management strategy using short-duration grazing and fertilization was simulated in a study with individual 'Ermelo' weeping lovegrass [Eragrostis curvula (Shrad.)Nees] plants. Influence of 2 levels of clipping [unclipped during the growing season and clipped (C) to 10-cm stubble height each time regrowth reached 40 cm]; fertilizer [unfertilized and 70-34-44 kg N-P-K/ha (F)]; and watering frequency [irrigated to field capacity at 7- (WET) and 14- (DRY) day intervals] on cumulative herbage dry matter yield, crude protein yield, and water-use efficiency, and root mass of individual weeping lovegrass plants grown in soil contained in polyethylene tubes was determined. Clipping combined …


Quantification Of Spermatozoa In The Sperm-Storage Tubules Of Turkey Hens And The Relation To Sperm Numbers In The Perivitelline Layer Of Eggs, J. P. Brillard, M. R. Bakst Jan 1990

Quantification Of Spermatozoa In The Sperm-Storage Tubules Of Turkey Hens And The Relation To Sperm Numbers In The Perivitelline Layer Of Eggs, J. P. Brillard, M. R. Bakst

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

This study was conducted to determine the number of spermatozoa residing in the oviduct sperm-storage tubules (SST) and the relationship between these numbers and the number of spermatozoa embedded in the perivitelline layer of oviductal eggs after a single insemination of 200 X 104 spermatozoa. The SST of hens inseminated within one week before the expected onset of egg production were filled faster (4 h vs. 2 days) and possessed more spermatozoa (4.1 vs. 2.0 X 106) than the SST of hens inseminated after the onset of egg production. Furthermore, for hens in egg production, significantly fewer …


Concentrations Of Insulin-Like Growth Factor-I In Blood And Ovarian Follicular Fluid Of Cattle Selected For Twins, S. E. Echternkamp, L. J. Spicer, K. E. Gregory, S. F. Canning, J. M. Hammond Jan 1990

Concentrations Of Insulin-Like Growth Factor-I In Blood And Ovarian Follicular Fluid Of Cattle Selected For Twins, S. E. Echternkamp, L. J. Spicer, K. E. Gregory, S. F. Canning, J. M. Hammond

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Recent studies have implicated insulin-like growth factor I (IGF-I) as an intraovarian regulator of follicular growth and differentiation. Therefore, we investigated the possibility that cattle selected for twin births may have increased concentrations of IGF-I within the ovarian follicle and(or) in peripheral blood. The estrous cycles of 14 cows with histories of producing twins and 12 control monotocous cows were synchronized with 35 mg of prostaglandin F (PGF). Blood and follicular fluid were collected 48-50 h post-administration of PGF. (follicular phase of the estrous cycle). Concentrations of IGF-I were measured by RJA after acid-ethanol treatment …


Comparative Attraction Of Four Different Fiberglass Traps To Various Age And Sex Classes Of Stable Fly (Diptera: Muscidae) Adults, Jerome Hogsette, Joseph Ruff Jan 1990

Comparative Attraction Of Four Different Fiberglass Traps To Various Age And Sex Classes Of Stable Fly (Diptera: Muscidae) Adults, Jerome Hogsette, Joseph Ruff

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

An Alsynite cylinder trap and three different Williams cross-configuration traps with three adhesives were compared to determine their relative attraction to stable fly, Stomoxys calcitrans (L.), adults. Williams traps coated with Olson Sticky Stuff performed as well as Williams traps coated with Tack Trap, thus allowing fly samples collected with either adhesive to be compared. The cylinder trap captured fewer total flies,but more flies per cm2 than any of the Williams traps. Sex ratio of flies captured on the cylinder trap was 50:50, while the three Williams traps captured predominantly males. The cylinder trap captured a larger percentage of …


Leafy Spurge: Threat To Central Plains Grasslands, Robert A. Masters Jan 1990

Leafy Spurge: Threat To Central Plains Grasslands, Robert A. Masters

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Leafy spurge (Euphorbia esula L.) is a noxious weed that threatens grasslands in the central and northern Great Plains and the prairie provinces of Canada. Leafy spurge threatens prairie communities by displacing native species and reducing species diversity. Effective management of this undesirable plant requires that one be able to identify leafy spurge, understand the characteristics that contribute to its aggressive habit, and be aware of practices that are available to control this noxious weed. The aggressive habit of leafy spurge is related to its ability to reproduce both by seed and by numerous adventitious shoot buds located along …


Intramuscular Collagen And Serum Hydroxyproline As Related To Implanted Testosterone, Dihydrotestosterone And Estradiol-17Β In Growing Wethers, L. F. Miller, M. D. Judge, B. D. Schanbacher Jan 1990

Intramuscular Collagen And Serum Hydroxyproline As Related To Implanted Testosterone, Dihydrotestosterone And Estradiol-17Β In Growing Wethers, L. F. Miller, M. D. Judge, B. D. Schanbacher

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Relationships of implanted testosterone, dihydrotestosterone and estradiol-17β to collagen degradation and intramuscular collagen concentration and stability were determined. Intramuscular collagen content, solubility and shrinkage temperature and serum hydroxyproline were analyzed in groups of six rams, wethers, and wethers implanted with various levels of testosterone or dihydrotestosterone (Exp. 1) and groups of 10 rams, wethers and wethers implanted with estradiol-17β, dihydrotestosterone or a combination of these two steroids (Exp. 2). Intramuscular collagen content in both experiments was higher (P < .05) in muscles of rams than in muscles of wethers. Administration of the highest level of testosterone to wethers raised (P < .05) total and insoluble intramuscular collagen to concentrations noted in rams. Administration of the testosterone metabolite, dihydrotestosterone, to wethers had no effect on intramuscular collagen. Administration of estradiol-17β to wethers tended to raise concentrations of intramuscular collagen so that they were no longer lower (P < .05) than those in rams. Collagen stability as measured by solubility and thermal shrinkage temperature did not differ among rams, wethers or implanted wethers (P > .05). Increases in collagen accretion due to hormone administration were observed to be the result of increases in the insoluble portion of …


Concentrations Of Insulin-Like Growth Factor-I In Blood And Ovarian Follicular Fluid Of Cattle Selected For Twins, S. E. Echternkamp, L. J. Spicer, K. E. Gregory, S. F. Canning, J. M. Hammond Jan 1990

Concentrations Of Insulin-Like Growth Factor-I In Blood And Ovarian Follicular Fluid Of Cattle Selected For Twins, S. E. Echternkamp, L. J. Spicer, K. E. Gregory, S. F. Canning, J. M. Hammond

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Recent studies have implicated insulin-like growth factor I (IGF-I) as an intraovarian regulator of follicular growth and differentiation. Therefore, we investigated the possibility that cattle selected for twin births may have increased concentrations of IGF-I within the ovarian follicle and(or) in peripheral blood. The estrous cycles of 14 cows with histories of producing twins and 12 control monotocous cows were synchronized with 35 mg of prostaglandin F2a (PGF2a). Blood and follicular fluid were collected 48-50 h post-administration of PGF2a (follicular phase of the estrous cycle). Concentrations of IGF-I were measured by RJA after acid.ethanol treatment of …