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Articles 1 - 13 of 13

Full-Text Articles in Life Sciences

Soil Heat And Water Flow With A Partial Surface Mulch, Sang-Ok Chung, Robert Horton Jr. Dec 1987

Soil Heat And Water Flow With A Partial Surface Mulch, Sang-Ok Chung, Robert Horton Jr.

Agronomy Publications

A computer model using the alternating direction implicit (ADI) finite difference method to study two-dimensional coupled soil heat and water flow with a partial surface mulch cover is developed. A new, simplified computational procedure, which has only tridiagonal matrix problems, for the ADI method is introduced. The model uses a soil surface energy balance equation to determine soil surface boundary conditions for both heat and water flow. The inputs required for the computer simulations are weather data, soil thermal and hydraulic properties, and mulch data. Numerical experiments are performed to examine the effects of soil type, mulch width, and weather ...


The Isolation And Identification Of Filamentous Fungi From Distribution Systems, Ground Water, Cisterns And Hemodialysis Water, Tammy J. Liles Aug 1987

The Isolation And Identification Of Filamentous Fungi From Distribution Systems, Ground Water, Cisterns And Hemodialysis Water, Tammy J. Liles

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Arts and Sciences at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science in Biology by Tammy J. Liles on August 18, 1987.


The Identity Of The Genus Neowawraea (Euphorbiaceae), W. John Hayden Apr 1987

The Identity Of The Genus Neowawraea (Euphorbiaceae), W. John Hayden

Biology Faculty Publications

On the basis of newly acquired morphological evidence gathered in the course of floristic studies, the monotypic genus Neowawraea Rock is now recognized as a species of Flueggea Willd. and is renamed F. neowawraea W. J. Hayden. Taxonomic documentation presented for F. neowawraea includes an expanded morphological description, a map showing its widely scattered distribution in the Hawaiian Islands to which the species is endemic, and discussions of type specimens, common names, and its extreme rarity. The combination of flowers in pedicellate axillary clusters, the lobed staminate disk, pistillode, extrorse anthers, hemitropous ovules, and, especially, the smoothish dry seeds with ...


Anatomy And Affinities Of Penthorum, Melanie Lynn Haskins, W. John Hayden Feb 1987

Anatomy And Affinities Of Penthorum, Melanie Lynn Haskins, W. John Hayden

Biology Faculty Publications

The genus Penthorum L. consists of two species of perennial herbs, P. sedoides of eastern North America and P. chinense of eastern Asia. Penthorum has long been considered intermediate between Crassulaceae and Saxifragaceae. An anatomical study of both species was undertaken to contribute to a better understanding of the relationships of these plants. Prominent anatomical features of Penthorum include: an aerenchymatous cortex and closely-spaced collateral vascular bundles of stems; one-trace unilacunar nodes; brochidodromous venation, rosoid teeth bearing hydathodes, and anomocytic stomata of leaves; angular vessel elements with many-barred scalariform perforation plates and alternate to scattered intervascular pits; thin-walled nonseptate fiber-tracheids ...


Clover Infertility Of Sheep : Continuing Problem, N R. Adams, Keith Croker Jan 1987

Clover Infertility Of Sheep : Continuing Problem, N R. Adams, Keith Croker

Journal of the Department of Agriculture, Western Australia, Series 4

Some varieties of subterranean clover, notably Dinninup, Dwalganup and Yarloop, contain compounds which act like the female sex hormone oestrogen. These plant oestrogens, or "phyto-oestrogens", interfere with the fertility of sheep and depress the percentage of lambs born.

Over the past 10 years our understanding of clover infertility has increased, and we can now gauge the extent of this residual problem. In fact, there is a widespread but low-level incidence of infertility which does not greatly affect individial farms but which has an important impact on the State's sheep production.


Biosynthesis Of 1-Aminocyclopropane-1-Carboxylic Acid And Ethylene From [Delta]-Aminolevulinic Acid In Ripening Tomato Fruits , Diaa El-Deen Ahmed El-Rayes Jan 1987

Biosynthesis Of 1-Aminocyclopropane-1-Carboxylic Acid And Ethylene From [Delta]-Aminolevulinic Acid In Ripening Tomato Fruits , Diaa El-Deen Ahmed El-Rayes

Retrospective Theses and Dissertations

A new pathway for ethylene (C[subscript]2H[subscript]4) biosynthesis, which utilizes [delta]-aminolevulinic acid (ALA) as a precursor of 1-aminocyclopropane-1-carboxylic acid (ACC), the immediate precursor of C[subscript]2H[subscript]4, is presented. ALA enhanced ACC accumulation to 410% and C[subscript]2H[subscript]4 production to 232% of the control. The C[subscript]2H[subscript]4 production rate varied with the ALA concentration and the stage of tomato fruit development. As the ALA concentration increased from zero to 40 mM, the C[subscript]2H[subscript]4 production rate increased. Both treated and untreated pericarp discs from fruits ...


Enhanced Degradation Of Isofenphos By Soil Microorganisms, Kenneth D. Racke, Joel R. Coats Jan 1987

Enhanced Degradation Of Isofenphos By Soil Microorganisms, Kenneth D. Racke, Joel R. Coats

Entomology Publications

Laboratory experiments were conducted to investigate the enhanced degradation of isofenphos [ 1- methylethyl 24 [ethoxy[ (1-methylethyl)amino]phosphinothioyl]oxy] benzoate] in soil and to elucidate the microbiology of this phenomenon. [U-ring-'4CIIsofenphos was most rapidly degraded in Iowa cornfield soils that had a history of isofenphos insecticide use. Between 13 and 42% of an applied dose of 5 ppm remained as isofenphos after 4 weeks in soil with isofenphos use history, whereas between 63 and 75% remained in comparable nonhistory soils. Soils with enhanced isofenphos degradation contained an adapted population of soil microorganisms responsible for the degradation observed. Degradation products ...


Regulation Of Kentucky Bluegrass (Poa Pratensis L) Morphogenesis By Growth Retardants And Exogenous Ethylene , Kenneth Lynn Diesburg Jan 1987

Regulation Of Kentucky Bluegrass (Poa Pratensis L) Morphogenesis By Growth Retardants And Exogenous Ethylene , Kenneth Lynn Diesburg

Retrospective Theses and Dissertations

Inconsistent efficacy has limited the application of turfgrass growth retardants to low-traffic, less-visible areas. More information is needed regarding the environmental conditions in which plants are more sensitive to growth regulation;A three-year field study was conducted to determine if the seasonal growth phases of Poa pratensis had any effect on plant receptivity to five growth retardants. Mefluidide and amidochlor were more effective in spring, flurprimidol in summer, while ethephon and paclobutrazol were equally effective across seasons. The greatest differences in growth retardation appeared between the spring reproductive and summer vegetative growth phases. It is concluded, therefore, that the transition ...


New And Corrected Records Of The Flora Of Nebraska, Steven B. Rolfsmeier, Robert B. Kaul, David M. Sutherland Jan 1987

New And Corrected Records Of The Flora Of Nebraska, Steven B. Rolfsmeier, Robert B. Kaul, David M. Sutherland

Biology Faculty Publications

New distributional data are provided for 27 species of vascular plants in Nebraska, eight newly recorded as growing wild in the State. The record of one species previously attributed to the State is shown to be based upon misidentified specimens, the range of another is shown to be much more restricted in Nebraska than previously reported, and nomenclature is corrected for two species.


The Potential For Skeleton Weed, John Dodd, F. D. Panetta Jan 1987

The Potential For Skeleton Weed, John Dodd, F. D. Panetta

Journal of the Department of Agriculture, Western Australia, Series 4

Since its introduction into Australia during the 900s skeleton weed has become one of the most economically significant weeds. Its presence in cereal crops in south-eastern Australia has caused suvere yield reductions and harvesting problems.

Skeleton weed was first found on a Western Australian farm in 963. Since then it has been the subject of an intensive eradication campaign organised by the Agricultural Protection Board and funded by an annual levy on wheat growers. Such campaigns, which rely mainly on volunteer searchers, do not exist in eastern Australia because the weed is so widespread it would be impossible to eradicate ...


Variation In Wheat Protein Content : The Effect Of Environment, G B. Crosbie, Harry Fisher Jan 1987

Variation In Wheat Protein Content : The Effect Of Environment, G B. Crosbie, Harry Fisher

Journal of the Department of Agriculture, Western Australia, Series 4

Over the past 20 years, the average protein content of WesternAustralian wheat has ranged from 9.3 to 12.0 per cent, with a mean level of 10.4 per cent. At most grain receival points, in any one season, individual loads can often vary in protein content by as much as 5 per cent protein or more. Rainfall and soil fertility account for much of this variation.


Trends In Wheat Protein/Yield Relationships, G B. Crosbie, Harry Fisher, Bryan Whan Jan 1987

Trends In Wheat Protein/Yield Relationships, G B. Crosbie, Harry Fisher, Bryan Whan

Journal of the Department of Agriculture, Western Australia, Series 4

The major concern of wheat breeders in WesternAustralia has been to increase grain yield while maintaining quality at an acceptable level. There has been no concious effort to select for protein content. It is of interrest, therefore, to compare the relationship between yield and protein of varieties which have been prominent in Western Australia at various times, to see what effects yield increases have had on protein content and the extent of any variation which might exist.


Evaluation Of Repellent Seed Treatments And Effects On Early Corn Performance, Ann E. Koehler, Ron J. Johnson, Orvin C. Burnside, Stephen R. Lowry Jan 1987

Evaluation Of Repellent Seed Treatments And Effects On Early Corn Performance, Ann E. Koehler, Ron J. Johnson, Orvin C. Burnside, Stephen R. Lowry

Agronomy & Horticulture -- Faculty Publications

A combination of field, field enclosure, and germination chamber studies was used to evaluate the effects of methiocarb [3,5-dimethyl-4-(methylthio)phenol methylcarbamate] and thiram (tetramethylthiuram disulfide) repellent seed treatments on early corn performance. The thiram treatments used (0.08, 0.4,0.8,0.5,1.25, and 2.5% active ingredient by corn seed weight) had negligible effects on germination/emergence time or on com plant heights. The thiram treatments never reduced stand counts in comparison to controls, but apparently increased stand counts in some trials, particularly under wet conditions. The methiocarb treatments evaluated (0.5, 1.25 ...