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Articles 841 - 870 of 1200

Full-Text Articles in Fresh Water Studies

Annual Medic Evaluation On Eradu Sandplain Soil - 3 M Rows., Bradley Nutt, M. K. Laslett Jan 1988

Annual Medic Evaluation On Eradu Sandplain Soil - 3 M Rows., Bradley Nutt, M. K. Laslett

Experimental Summaries - Plant Research

Trial 88EC16

Location: East Chapman Research Station

Inoculated and lime pelleted seed was hand sown into 3m rows at 0.25 g/m. All the medics were inoculated with WSM 540 which may have been less effective with some of the M. littoralis and M. tornata varieties. The 1988 season was very good in terms of frequency and amount of rainfall which is reflected in the high seed yields compared to 1987.


Evaluation Of New Pasture Legume Species In Terms Of Summer Feeding Value And Effects On Wool Production., Tess Casson Jan 1988

Evaluation Of New Pasture Legume Species In Terms Of Summer Feeding Value And Effects On Wool Production., Tess Casson

Experimental Summaries - Plant Research

Trial 86KA71

Location: Private farm 'Monalta' - south-east of Katanning.

As outlined by S. Flecker in the 1987 summary for this trial, the expected result of the research is that the feeding value of burr medic pastures will be greater than the feeding value of sub. clover and barrel medic pasture, particularly over the dry summer/autumn period.


Soil-Plant Organochlorine Pesticide Research., Tony Albertsen Jan 1988

Soil-Plant Organochlorine Pesticide Research., Tony Albertsen

Experimental Summaries - Plant Research

88MA42, 88BU18, 88BU21, 88BU22, 88BY16, 88AL20, 88AL21, 88AL22, 88BY9, 88 BY1, 88BY11, 88BY12, 88BY13, 88BY14, 88BY15, 88BU19, 88BU20, 88MA43, 88MA44, 88MA45, 88MA46, 86V1, 86V2, 84V2.

Locations: Albany, Bunbury, Busselton and Manjimup.

In 1988 a research programme was initiated to help define the relationship between soil and plant contamination. Two main experiments were established 1) Pasture contamination in annual and perennial grazed swards. 2) Plant species contamination in a wider range of pasture and crops.


Effect Of Deep Ripping And Aphid Infestation On Pasture Production., Bradley Nutt, M. K. Laslett Jan 1988

Effect Of Deep Ripping And Aphid Infestation On Pasture Production., Bradley Nutt, M. K. Laslett

Experimental Summaries - Plant Research

Trial 88EC18

Location: East Chapman Research Station.

Half the trial site was cultivated to 30cm at the break of the season and the whole site was normally cultivated. Weeds were then sprayed with Roundup at 1 1/ha prior to seeding with an eight run cone seeder. The plots were kept weed free during the year by hand weeding. The root distribution was calculated from soil cores taken in 20 cm increments on 20 August. Aphid cortrol consisted of spraying every two weeks with Pirimor at 140 g/ha between July and October. Lorsban at 150 ml/ha was used for the last …


Serradella Establishment On Light Textured Soil., Bradley Nutt, M. K. Laslett Jan 1988

Serradella Establishment On Light Textured Soil., Bradley Nutt, M. K. Laslett

Experimental Summaries - Plant Research

Trial 87GE81

Location: East Chapman Research Station.

Evaluate early maturing serradella lines on deep sands.


Pasture Cultivar Comparison On Red Loam Soil - Large Plots., Bradley Nutt, M. K. Laslett Jan 1988

Pasture Cultivar Comparison On Red Loam Soil - Large Plots., Bradley Nutt, M. K. Laslett

Experimental Summaries - Plant Research

Trial 88GE34

Locations : North Mullewa Research Station and Morawa Agricultural School.

Evaluation of pasture cultivars in large plots.


Ryegrass Species Evaluation., L. Cransberg Jan 1988

Ryegrass Species Evaluation., L. Cransberg

Experimental Summaries - Plant Research

Trial 88AL31

Location: Takalarup

To identify productive grass species for the short, medium and long term in southern high rainfall environment.


Pasture Cultivar Comparison - Large Plots., Bradley Nutt, M. K. Laslett Jan 1988

Pasture Cultivar Comparison - Large Plots., Bradley Nutt, M. K. Laslett

Experimental Summaries - Plant Research

Trial 88TS63

Location: Perenjori

To evaluate the effect of various legume pasture cultivars on pasture and crop production.


Long Season Serradella Evaluation., L. Cransberg Jan 1988

Long Season Serradella Evaluation., L. Cransberg

Experimental Summaries - Plant Research

Trial 88AL32

Location: Walpole

To select productive and persistent serradella lines for the deep acidic sands in the very high rainfall zone on the south coast.


Surface Drainage Trial., Tony Albertsen Jan 1988

Surface Drainage Trial., Tony Albertsen

Experimental Summaries - Plant Research

Trial 86V1

Location: Vasse Research Station

Laser levelling demonstration areas at Vasse Research Station have improved surface drainage and reduced waterlogging, flooding and salt accumulation. Reseeding these laser treated areas has resulted in greater pasture productivity and stock carrying capacity. The overall cost of this exercise has to be met by increased animal productivity.


National Subterranean Clover Improvement Programme, P. Nichols Jan 1988

National Subterranean Clover Improvement Programme, P. Nichols

Experimental Summaries - Plant Research

Trial 88PE27 - University Field Station, Shenton Park
Trial 88WH43 - Wongan Hills Research Station.

The project aims to develop, by breeding and selection, better adapted and more productive low-oestrogen cultivars of subterranean clover for a range of environments in southern Australia. The programme is a collaborative one with the University of Western Australia and consists of two phases (i) early generation selection, which involves selecting varieties satisfying primary selection criteria; and (ii) field evaluation of advanced lines, which is conducted by the Departments of Agriculture in each State and co-ordinated by the Plant Breeder. The first phase is conducted …


Annual Medic Evaluation On Eradu Sandplain Soil - Plots, Bradley Nutt, M. K. Laslett Jan 1988

Annual Medic Evaluation On Eradu Sandplain Soil - Plots, Bradley Nutt, M. K. Laslett

Experimental Summaries - Plant Research

Trial 88EC17

Location: East Chapman Research Station.

The plots were hand sown at 2 g/m2 of inoculated and lime pelleted seed. The medics were inoculated with WSM540 which may have been ineffective on some of the M. littoralis and M. tornata varieties. The time taken to form ripe pods was monitored to gain some extra measure of maturity besides flowering time for comparing wide ranges of species. The ripening time involved was very similar over all the varieties, averaging out to 44 days after the flower opens. What appears to be a more important factor when considering maturity is the …


Selection And Development Of Early Maturing Varieties Of Murex Medic., D. J. Gillespie Jan 1988

Selection And Development Of Early Maturing Varieties Of Murex Medic., D. J. Gillespie

Experimental Summaries - Plant Research

Trial 88A25, 88MO44, 88NA83, 88AL15

Location: Avondale, New Norcia, Darkan, Cranbrook, Arthur River, Kellerberrin North Quairdading, Gabalong, Merredin, Badgebup and Pingrup.

Over 300 recent overseas introductions of murex medic were evaluated in rows at South Perth in 1988. Of these 15 selections were identified with acceptable spinniness that flower in 100 days or less. Four years ago there was only one selection flowering in under 110 days and that was spiny!

These selections will be evaluated in small plot trials in several country sites in 1989.

This programme aims to identify superior varieties to Zodiac which was released in 1988.


Dryland Pasture Legume Programme, C. K. Revell, G. Croker, J. Simmons, L. Heinrich Jan 1988

Dryland Pasture Legume Programme, C. K. Revell, G. Croker, J. Simmons, L. Heinrich

Experimental Summaries - Plant Research

1. Medic variety evaluation

a. Row Evaluation - 88ME122 - Merredin.
This method of assessment was used to test a range of new medic material originating from the South Australian Department of Agriculture.

b. Evaluation of burr medics on Morrel soils. - 88ME84 - Nokaning.

c. Evaluation of burr medics on Whitegum soils. 88ME85 - North Kellerberrin.

d. Evaluation of Santiago in low rainfall areas - 88ME86 - Mukinbudin.

e. Selection of early maturing M. murex. 88SC30 - Merredin.

f. Medic species evaluation - large plots. 88NO88 - Tammin.

g. Medic species evaluation - large plots. 85M43 - Merredin Research …


Limnological Monitoring Data For Lake Mead During 1987: Technical Report No. 20, Larry J. Paulson Jan 1988

Limnological Monitoring Data For Lake Mead During 1987: Technical Report No. 20, Larry J. Paulson

Publications (WR)

Limnological monitoring was conducted in Las Vegas Bay and Boulder Basin from April to December of 1987. The purpose of the monitoring was to (i) document possible changes in water quality resulting from decreased phosphorus loading in Las Vegas Wash, and (ii) establish a data base for evaluating the adequacy of water quality standards.


Fish Aid: The Lake Mead Fertilization Project, Richard Axler, Larry Paulson, Peter Vaux, Patrick Sollberger, Donald H. Baepler Jan 1988

Fish Aid: The Lake Mead Fertilization Project, Richard Axler, Larry Paulson, Peter Vaux, Patrick Sollberger, Donald H. Baepler

Publications (WR)

Sport fishing at Lake Mead in Nevada and Arizona is a resource valued at nearly $100 million per year to southern Nevada. During the past two decades, salmonids, mostly trout, have disappeared entirely, the largemouth bass catch has drastically declined despite greater fishing pressure, and the condition factors for striped bass have steadily deteriorated. It appears that a major reduction in phosphorus loading caused by the upstream impoundment of the Colorado River to form Lake Powell in 1963 and advanced wastewater treatment removal of phosphorus from domestic wastewater inflows in 1981 are the principal factors responsible for decreased production at …


Changes In The Morphometry Of Las Vegas Wash And The Impact On Water Quality, Richard A. Roline, James J. Sartoris, U.S. Bureau Of Reclamation Jan 1988

Changes In The Morphometry Of Las Vegas Wash And The Impact On Water Quality, Richard A. Roline, James J. Sartoris, U.S. Bureau Of Reclamation

Publications (WR)

Las Vegas Wash, a natural wash east of Las Vegas, Nevada, carries stormwater, groundwater drainage, and sewage effluent from two sewage treatment plants to Lake Mead. Over 80 percent of the normal discharge of approximately 3.4 m3/s (120 ft3/s) consists of effluent from the City of Las Vegas and Clark County sewage treatment plants. Beginning in the 1950s, a large wetland area developed along the wash that supported waterfowl populations and contributed to some water quality transformations. Heavy rains and subsequent flooding in the area in 1983 and 1984 resulted in erosion and channelization that greatly …


Lake Mead Prefertilization Study: Preliminary Nutrient Enhancement Studies In Lake Mead, Richard P. Axler, Larry J. Paulson, Patrick J. Sollberger, Donald H. Baepler, U.S. Bureau Of Reclamation Nov 1987

Lake Mead Prefertilization Study: Preliminary Nutrient Enhancement Studies In Lake Mead, Richard P. Axler, Larry J. Paulson, Patrick J. Sollberger, Donald H. Baepler, U.S. Bureau Of Reclamation

Publications (WR)

Studies conducted by the University of Nevada-Las Vegas (UNLV), the Nevada Department of Wildlife (NDOW), the Arizona Game and Fish Department (AGFD), The Nevada Division of Environmental Protection (NDEP), and the United States Bureau of Reclamation (USBR) have identified decreased algal production as a major factor involved in the decline of the Lake Mead sport fishery. Phosphorus-laden silt particles in the Colorado River have been sedimenting out in Lake Powell since the completion of Glen Canyon Dam 286 miles upstream in 1963. This sharp decrease in phosphorus loading to Lake Mead (>5000 tons per year) has resulted in decreased …


Thermal Tolerances And Preferences Of Fishes Of The Virgin River System (Utah, Arizona, Nevada), James E. Deacon, Paul B. Schumann, Edward L. Stuenkel Oct 1987

Thermal Tolerances And Preferences Of Fishes Of The Virgin River System (Utah, Arizona, Nevada), James E. Deacon, Paul B. Schumann, Edward L. Stuenkel

Publications (WR)

Critical thermal maxima (CTM) and thermal preferenda of the common fishes of the Virgin River were examined. Differences in final temperature preferenda and CTM for species with low thermal lability (speckled dace, spinedace, roundtail chub) correspond well with differences in their distribution and abundance in the river. These species shifted their acute thermal preferences relatively little as acclimation temperature increased. For thermally labile species (woundfin, red shiner, desert sucker, and fiannehnouth sucker), the final preferendum is a less precise indicator of probable distribution. The woundfin, an endangered fish, has a high CTM (39.5 C at 25 C acclimation) and a …


Benthic Invertebrates And Crayfish Of Lake Mead, Susan K. Peck, William L. Pratt, James E. Pollard, Larry J. Paulson, Donald H. Baepler Sep 1987

Benthic Invertebrates And Crayfish Of Lake Mead, Susan K. Peck, William L. Pratt, James E. Pollard, Larry J. Paulson, Donald H. Baepler

Publications (WR)

The objectives of this study were to:

1. Establish baseline densities of benthic invertebrates and relative abundance of crayfish in Lake Mead.

2. Evaluate the distributions of benthic organisms and crayfish in relation to existing habitat conditions and 1imnological characteristics of Lake Mead.

3. Measure seasonal changes in abundances of benthic organisms and crayfish in Lake Mead.

4. Compare observations of Procambarus clarkii life history in Lake Mead to reports from other aquatic systems.

5. Evaluate the importance of benthic organisms and crayfish as food sources for game fish in Lake Mead.


Estimation Of Food Limitation In Daphnia Pulex From Boulder Basin, Lake Mead, Thomas Mark Bartanen Aug 1987

Estimation Of Food Limitation In Daphnia Pulex From Boulder Basin, Lake Mead, Thomas Mark Bartanen

Publications (WR)

In February, 1982 I began a year-long study to determine if growth and reproduction in Daphnia Pulex were limited by the amount of food available in Boulder Basin, Lake Mead. To determine this, I made monthly collections of Daphnia Pulex and natural lake seston from an already established station in Boulder Basin. I cultured the Daphnia Pulex under simulated field conditions in a flow-through feeding apparatus using four different food regimes; 1-natural lake seston filtered through 80 um mesh to remove other zooplankton, 2-lake seston (as above) with an enrichment of 103 cells-ml-1 of Chlamydomonas reinhardti, 3-lake …


An Annual Study Of Phytoplankton Composition And Associated Environmental Conditions Of Lake Trashmore, Virginia Beach, Virginia, Seba B. Sheavly Jul 1987

An Annual Study Of Phytoplankton Composition And Associated Environmental Conditions Of Lake Trashmore, Virginia Beach, Virginia, Seba B. Sheavly

Biological Sciences Theses & Dissertations

A 12 month study of Lake Trashmore was conducted on phytoplankton composition, inorganic nutrients and their seasonal associations. The dominant phytoplankton groups observed were diatoms, chlorophyceans and cyanobacteria. Phytoplankton assemblage patterns were coupled with pH, temperature, dissolved oxygen, nitrites and silicates. Diatoms dominated during periods of high nutrient concentrations, cooler temperatures and an unstable water column. Cyanobacteria forms dominated during periods of warmer temperatures, higher pH and decreased nitrogen and dissolved oxygen concentrations. A seasonal community shift occurred from cyanobacterial dominance to chlorophycean dominance when pH levels decreased. The lake is eutrophic based on indices of chlorophyll a concentrations, transparency …


Lake Mead Cover Enhancement Project, Jennifer Stevens Haley, Suzanne Leavitt, Larry Paulson, Donald H. Baepler Jul 1987

Lake Mead Cover Enhancement Project, Jennifer Stevens Haley, Suzanne Leavitt, Larry Paulson, Donald H. Baepler

Publications (WR)

Ninety-three wildlife agencies were surveyed for information on their attempts to improve fish habitat. In addition, an annotated bibliography including over 100 summaries was completed on: 1. largemouth bass cover requirements and preferences, 2. use and effectiveness of artificial cover, 3. aquatic plant introduction and species requirements for germination and establishment, 4. terrestrial plant introduction and species requirements for germination and establishment, and 5. nutrient exchange between sediment, aquatic plants, and water. A reconnaissance of existing terrestrial and aquatic vegetation was completed in June 1986 including the production of a video tape of the Nevada shoreline of Lake Mead. Cover …


Las Vegas Wash And Lake Mead Proposed Water Quality Standards: Revisions And Rationale, State Of Nevada: Division Of Environmental Protection May 1987

Las Vegas Wash And Lake Mead Proposed Water Quality Standards: Revisions And Rationale, State Of Nevada: Division Of Environmental Protection

Publications (WR)

Rationale of review and for proposed changes to the Nevada Pollution Control Regulations (NAC 445.1354, 445.1355, 445.1356, 455.1367, 445.1352, 445.1353, 445.1350, 445.1351) before the State Environmental Commission on June 23 and 24, 1987.


Comparison Of Littoral And Limnetic Zooplankton Communities Of Lake Mead, Patrick Joseph Sollberger May 1987

Comparison Of Littoral And Limnetic Zooplankton Communities Of Lake Mead, Patrick Joseph Sollberger

Publications (WR)

Microfaunal communities were studied in littoral (inshore) and limnetic (offshore) areas of the lower basin in Lake Mead to compare species composition and abundance between the two zones. Planktonic forms (zooplankton) dominated inshore and offshore habitats and the occurrence of littoral species was low. Therefore, high similarity in zooplankton species composition was found among all sampling stations. This was perhaps due to two main factors: (i) the physical and chemical environment among the stations were very similar and (ii) the lack of aquatic vegetation in the littoral zone reduced the occurrence of littoral species.

Although species composition did not vary …


Raw Nutrient Data, Leanna Gail May 1987

Raw Nutrient Data, Leanna Gail

Publications (WR)

Data collected at various stations around Lake Mead. Includes information about substances present in various water samples.


Disease And Insect Resistance; Murex Medic Evaluation; Legume Species Phasic Development, D J. Gillespie Jan 1987

Disease And Insect Resistance; Murex Medic Evaluation; Legume Species Phasic Development, D J. Gillespie

Experimental Summaries - Plant Research

A summary of the performance of the control varieties (four replications) is shown in Table 3. A summary of the root rot ratings for some varieties showing a range of root rot susceptibility to all four pathogens is given in Table 4. Plant weights were recorded for all varieties tested against the three pathogens in the Western Australian experiments. Results for 12 of the 60 varieties are shown in Table 5. Murex medic evaluation. 86MT56 (Mount Barker), Gravelly loam pH 5.2 (water). 86NA46 (Darken) Loamy sand pH 5.4 86M037 (Regans Ford) Fine red sand pH 5.8 All sites were established …


Saffrom Thistle, Seed Set Control, J. R. Peirce, B. J. Rayner Jan 1987

Saffrom Thistle, Seed Set Control, J. R. Peirce, B. J. Rayner

Experimental Summaries - Plant Research

Trial 87ME119 - Saffron thistle, seed set control.

Trial 87TS38 - Saffron thistle control (seed set)

Trial 87JE42 - Seed set control in Saffron thistle.

All treatments had some measure of reducing seed production. Best control was obtained by applying chemicals just at or prior to flowering.


History Effects On Wheat Response., J. H. Moore, G. R. Dean Jan 1987

History Effects On Wheat Response., J. H. Moore, G. R. Dean

Experimental Summaries - Plant Research

Trial 85AL42

To determine the effects of tillage, sowing density, and time of planting of Osprey and Aroona on the pest and disease incidence, early growth and yield.


Manipulation Of The Soil Seed Reserves Of Bromus Diandrus And B. Rigidus By Enhancing The Breakdown In Seed Dormancy., A H. Cheam Jan 1987

Manipulation Of The Soil Seed Reserves Of Bromus Diandrus And B. Rigidus By Enhancing The Breakdown In Seed Dormancy., A H. Cheam

Experimental Summaries - Plant Research

Location: South Perth Field Plots

Previous studies on the seed bank of Bromus diandrus indicated that shallow burial of newly shed seeds enhanced the breakdown in seed dormancy over the summer period. To bury the Bromus seeds one practical approach is to introduce sheep into the paddock.
This study is a repeat of the previous work but included B. rigidus, another species of Bromus, that is commonly ground growing in association with B. diandrus.
Location: South Perth Field Plots.