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Articles 2761 - 2790 of 3102

Full-Text Articles in Physical Sciences and Mathematics

Low Rainfall Pasture Programme, M Ewing Jan 1981

Low Rainfall Pasture Programme, M Ewing

Experimental Summaries - Plant Research

1) Variety Testing. 80ME28, 81ME29, 81ME28, 81ME33, 81ME34, 81LG30, 81TS25, 81M39, 81WH47, 81N032, 81M34.

2) Pasture Establishment. (1) Methods and times of sowing - 81M38, 80LG22. (2) Depth of undersowing - 81M41, 81LG31. (3) Herbicides on undersown clover - 81M031, 81TS26, 81ME32, 81M37.

3) Pasture Manipulation using Herbicides. 81M032, 81TS27, 81TS29, 81M36, 81ME31.

4) Medic Collections. Background. Medics introduced into Australia from a wide range of collection area were ·tested on three soil types near Merredin. The sites were: (1) Merredin Research Station - brown sandy loam. (2) East Merredin property of K. Cahill – brown clay loam. (3) Holleton …


Kabatiella Caulivor, Root Rot Resistance, Bluegreen Aphid, Asessment Of Medicago Murex, Clover Establishment Techniques, D J. Gillespie Jan 1981

Kabatiella Caulivor, Root Rot Resistance, Bluegreen Aphid, Asessment Of Medicago Murex, Clover Establishment Techniques, D J. Gillespie

Experimental Summaries - Plant Research

Kabatiella caulivora (clover scorch). In contrast to previous years where all overseas introductions and most crossbreds were tested for resistance to Kabatiella, only selected clovers are now being screened so as to reduce the number requiring testing to a manageable size. Root rot resistance screening. One hundred and seven clovers selected as low in formononetin, tolerant of clover scorch, mid to late season maturity, and reasonable winter vigour were tested at two sites for root rot resistance. Bluegreen aphid (BGA) resistance screening. Sub clover screening for bluegreen aphid resistance ranked from tolerant to susceptible (ratings at 49 days from commencement). …


1981 Trace Element Nutrition, J. W. Gartrell, R F. Brennan Jan 1981

1981 Trace Element Nutrition, J. W. Gartrell, R F. Brennan

Experimental Summaries - Plant Research

1. Long term copper trial - Newdegate Research Station - 66N14. 2. Zinc residual with OAP for wheat - 80NO31. 3. Zinc residual with OAP for wheat - 79ME22. 4. Zinc residual with OAP for wheat - 79ME23. 5. Zinc, sulphur and copper residual with OAP for wheat - 79WH66. 6. Wheat response to zinc rates - 81MO8. 7. Manganese on wheat and oats - 81KA29. 8. Molybdenum and ammonium sulphate (S/A) on wheat - 81NO40. 9. Molybdenum and ammonium sulphate on wheat - 81NO41. 10. Molybdenum and ammonium sulphate on wheat - 81NO39. 11. Mo, lime, Mg on sub. …


Minimum Tillage, Stubble Management, Deep Ripping, Newland Clearing, Residual Chemicals, R J. Jarvis Jan 1981

Minimum Tillage, Stubble Management, Deep Ripping, Newland Clearing, Residual Chemicals, R J. Jarvis

Experimental Summaries - Plant Research

A/ Long term Minimum Tillage Investigations (i) Continuous Cropping Sites - 77A16, 77WH17, 77M13, 78M25, 77E18, 77MT15, 78BA42 (ii) Rotational Sites - 77A43, 77WH88, 77M56, 77E52, 77MT51. B/ Minimum Tillage Investigations Including - Time of seeding Cultivars and varieties. Depth of cultivation. Depth of seeding. Nitrogen rates - 81WH8, 81N5, 81NA31, 81NA32, 81WH3, 81A2, 81M45, 81M46, 81GE24, 81N29, 81NA40, 81M24, 81M25, 81MO10, 81MO11, 81MO12. C/ Stubble Management Techniques - 79WH6, 79M7. Stubble Trials by Other Researchers - 78WH3, 78C3, 78M2, 81TS36. D/ Deep Ripping - 80A44, 77WH17, 81NO3, 81NO4, 80NO46, 81NA10, 81NA11, 79MO19, 81NO2, 81M45, 81MO39. 81M45, 81M45, 81ES58 ,81ES57, …


Spraytop/Barley Control, Ryegrass Herbicides, Bromegrass Control, J. E. Holmes Jan 1981

Spraytop/Barley Control, Ryegrass Herbicides, Bromegrass Control, J. E. Holmes

Experimental Summaries - Plant Research

Trials reported Spraytop control of bromegrass - 80NO50, 80BA45. Spraytop control of barley grass – 80NA65, 80NO51. Barley grass control - evaluation of Fixaven and Mataven – 81LG40, 81KA44. Pre- and post-emergent application of ryegrass herbicides – 81LG37. Bromegrass control Evaluation of herbicides effect on brome and crop – 81WH52. Evaluation of Glean – 81BA58, 81A53, 81WH51. Evaluation of Dual and Isopoturon – 81A52. Evaluation of Dual and Hoegrass – 80BA59. Screening herbicides for brome control – 81BA57. Evaluation of Glean - 81WH54, 81N27. Tank mixes for minimum tillage – 81M50, 81A56, 81N28, 81NA41. Evaluation of Sencor, Diuron, Trifluralin tank …


1981 Plant Viruses, G D. Mclean, J Sandow, T N. Khan, P. A. Portmann, R Mclean, M Grimm Jan 1981

1981 Plant Viruses, G D. Mclean, J Sandow, T N. Khan, P. A. Portmann, R Mclean, M Grimm

Experimental Summaries - Plant Research

1, Clover viruses - 81HA6, 81MA9, 81BR14, 81BY12, 81BH5, 81AL38, 81ES39 OBJECTIVES: To determine the extent of the 'Dinninup virus' problem (sub. clover mottle). To further assess the incidence of red leaf virus to determine the incidence of bean yellow mosaic virus. To note the incidence of sub. clover stunt virus. A. BYDV: Survey of incidence - 81BU1, 81BU2, 81BR11, 81BR12, 81MA6, 81MA7, 81AL31, 81AL32, 81JE14, 81JE15, 81KA21, 81KA22, 81NA28, 81N031, 81ES38, 81E26. 2. Barley yellow dwarf virus. BYDV: Genotype x insecticide studies - 81MN14, 81MT29, 81E28, 81MN14. BYDV: differences amongst barley genotypes - 81C19, 81WH31, 81BA30. BYDV: Resistance and …


Rapeseed, Oilseed Phenology, Linseed And Sunflower Trial, A G. Mckay Jan 1981

Rapeseed, Oilseed Phenology, Linseed And Sunflower Trial, A G. Mckay

Experimental Summaries - Plant Research

Nitrogen x time of sowing, two rapeseed varieties – 81AL21, 81BR2. Rapeseed establishment trial – 81AL47. Rapeseed harvesting methods – 81MT48. Shattering differences among rapeseed lines - 81MT49. Estimated pre-treatment pod shattering losses.

Oilseed phenology – 81MT47, 81WH57, 81A48, 81BA53, 81C37, 81E34. Comment: 81C37- severely infested with wild radish - not hqrvested. 81E34- early insect damage - not harvested. 81A48- yield data not available. 81MT47- yield potential of site reduced by waterlogging.

Kerb on rapeseed and linseed – 81GL6.

Sunflower agronomy trial – 80AL89.


Influence Of Planting Systems On Crop Growth And Soil Water Relations., D Tennant Jan 1981

Influence Of Planting Systems On Crop Growth And Soil Water Relations., D Tennant

Experimental Summaries - Plant Research

Summary of experimental results 1981. Influence of planting systems on crop growth and soil water relations. Rainfall infiltration, drainage and water use. Yields. The two late sown treatments of previous years were replaced in 1981 with deep ripping treatments. Details are presented in R. Jarvis' report. 77A16, 77WH17,


Investigations Of Ryegrass Toxicity., Brian A. Stynes Jan 1981

Investigations Of Ryegrass Toxicity., Brian A. Stynes

Experimental Summaries - Plant Research

81KA47, 81NA47, 81M047, 81KA48, 81NA45, 81M045, 81KA50, 81NA46, 81M046, To monitor the amount of toxin present in galls from the time of first head emergence until maturation of the ryegrass pastures. To relate the onset and development of toxicity to plant growth stages and climatic conditions in the different regions affected by annual ryegrass toxicity. To relate the level of toxicity to pasture density and to the number of galls present in the pasture. As part of the series of experiments done to monitor the amount of toxin present in pasture at a number of sites throughout the seasons, an …


Long Term Rotation Trials., I Rowland. Jan 1981

Long Term Rotation Trials., I Rowland.

Experimental Summaries - Plant Research

Long term rotation trials. 66M29/2083EX, 67Cl3/2332EX , 67N4/2333EX, 68E5/2474EX , 68SG5/2475EX , 73SG16. Lupins: Wheat Rotation. 79GE36/3288EX, 79GE37/3288E, 80TS3/3288EX, 73SG16/3229EX Continuous Cropping with Nitrogenous Fertiliser. 80NA6


Summary Of Experimental Results Field Trials 1981, P A. Rutherford Jan 1981

Summary Of Experimental Results Field Trials 1981, P A. Rutherford

Experimental Summaries - Plant Research

80NA46, 80NA45, 79TS27, 80A46, 80NA50, 79N036, 81M041, 81Pe12, 79KU1, Weed control on roaded catchments. Demonstration catchment. Chemical firebreaks on deep white sand. Chemical firebreak evaluation - long term. Residual herbicides for annual weed control - long term cost evaluation. Long-term weed control on Railway Track. Control of annual weeds on road shoulders


The Effect Of Soil Acidity On Crop And Pasture Production., W Porter, R Klemm Jan 1981

The Effect Of Soil Acidity On Crop And Pasture Production., W Porter, R Klemm

Experimental Summaries - Plant Research

SUMMARY The effects of lime and molybdenum applications on wheat and subterranean Clover were studied further. Wheat. In relation to lime use, my aim is to develop soil tests to be used to predict when a soil requires lime to produce maximum yield, and to predict the optimum rate of lime. Using the results from field trials commenced in 1980 and 1981 the soil parameters which may be used to predict lime responses in wheat have been narrowed down. From the relationships between soil data and lime responses it appears that soil ph (measured in 1:5 H20 or 1:5 N …


Experimental Summaries., M W. Perry, R N. Weir Jan 1981

Experimental Summaries., M W. Perry, R N. Weir

Experimental Summaries - Plant Research

Wheat Yield Potential Trials, 81BA4, 81WH7, 81KAS.Wheat-Regenerating Sandplain Lupin Rotation Trials, 79GE38, 79GE42.Nitrogen x Cycocel x Foliar Nutrients x Fungicide-on Wheat,81KA6. Historical Wheat Trials, 81A3, 81C4, 81SG22, 81WH6. Time of Planting on Cereal Yields, 81NA8, 81KA55.


Reproductive Biology And Recreational Fishery For Spotted Seatrout, Cynoscion Nebulosus, In The Chesapeake Bay Area, Nancy J. Brown Jan 1981

Reproductive Biology And Recreational Fishery For Spotted Seatrout, Cynoscion Nebulosus, In The Chesapeake Bay Area, Nancy J. Brown

Dissertations, Theses, and Masters Projects

No abstract provided.


Fish Predator-Prey Interaction In Areas Of Eelgrass (Zostera Marina), Joseph Lascara Jan 1981

Fish Predator-Prey Interaction In Areas Of Eelgrass (Zostera Marina), Joseph Lascara

Dissertations, Theses, and Masters Projects

No abstract provided.


The Socioeconomic And Fisheries Characteristics Of Virginia's Commercial Sport Fishing Industry, Anne R. Marshall Jan 1981

The Socioeconomic And Fisheries Characteristics Of Virginia's Commercial Sport Fishing Industry, Anne R. Marshall

Dissertations, Theses, and Masters Projects

No abstract provided.


Behavioral Response Of The Amphipod Gammarus Fasciatus And The Isopod Asellus Communis To Fish (Lepomis Macrochirus) And Dragon Fly (Gomphidae), Bill D. Saunders Jan 1981

Behavioral Response Of The Amphipod Gammarus Fasciatus And The Isopod Asellus Communis To Fish (Lepomis Macrochirus) And Dragon Fly (Gomphidae), Bill D. Saunders

Dissertations, Theses, and Masters Projects

No abstract provided.


Methods For Biological, Chemical, And Physical Analyses In Reservoirs, Penelope E. Kellar, Sherell A. Paulson, Larry J. Paulson Dec 1980

Methods For Biological, Chemical, And Physical Analyses In Reservoirs, Penelope E. Kellar, Sherell A. Paulson, Larry J. Paulson

Publications (WR)

This manual contains detailed descriptions of biological, chemical and physical sampling and analytical procedures used at the Lake Mead Limnological Research Center. The manual was prepared in response to requests made by numerous individuals involved in the Las Vegas Valley Water Quality Program. This manual represents what we consider to be a reasonably complete compilation of methods useful in studying both general and specific limnological questions. While each section is sufficiently detailed to be of use to investigators with little experience in limnological methodology, the methods can be used on a wide variety of lakes and reservoirs, with relatively little …


Distribution Of Trace Elements In A Warm Water Release Impoundment, J. Nix Oct 1980

Distribution Of Trace Elements In A Warm Water Release Impoundment, J. Nix

Technical Reports

A detailed water quality survey (including trace metals) was conducted on DeGray Reservoir in south west Arkansas from 1969 through 1975. The results of this investigation are used to describe physical and chemical processes which affect the concentration of many of the constituents found in the reservoir and river system. Detailed dissolved oxygen profiles as well as turbidity (% transmittance) profiles were useful in delineating the movement of water through the reservoir. Underflows, innerflows, and overflows were observed during different seasons. The development of a metalimnetic dissolved oxygen minima appears to be related to advective transport within the metalimnion. Metalimnetic …


An Analysis Of Residential Water Demand Schedules In Arkansas, Richard K. Ford, Joseph A. Zieger Oct 1980

An Analysis Of Residential Water Demand Schedules In Arkansas, Richard K. Ford, Joseph A. Zieger

Technical Reports

Water has held man's interest for centuries, and a considerable body of knowledqe has been developed about this subject, but it has only been considered only recently by decision makers in an economic sense. Because water is required to sustain life, the thought of its being an economic good to individuals has not been considered applicable or "fair" by those individuals who are concerned with its acquisition and distribution. Moreover, water has been in fairly abundant supply relative to demand for most of the country. However, as this situation is upset by increases in population and water use, a realization …


Mass Marking Of Mosquitofish: Preliminary Results, Bruce Vondracek, Wayne A. Wurtsbaugh, Joseph J. Cech Jr. Sep 1980

Mass Marking Of Mosquitofish: Preliminary Results, Bruce Vondracek, Wayne A. Wurtsbaugh, Joseph J. Cech Jr.

Watershed Sciences Faculty Publications

Three marking techniques were tested to determine their applicability for mosquitofish. Tetracycline drugs and DC Ar administered in the diet successfully marked laboratory-cultured mosquitofish, but exposure to direct sunlight in outdoor tanks resulted in the rapid disappearance of the marks. Preliminary data on fluorescent marks from a polystyrene pigment in a melamine-sulfonamide-formaldehyde resin forced into the dermal ,tissue with compressed air are more promising.

A t an optimal deliver pressure of 7.3 m Hg (140 p.s.i.) and spraying time of 15 sec., marking percentage is maximized and fish mortality is minimized. Mark retention time was up to 80 days in …


Effect Of Fish Size On Prey Size Selection In Gambusia Affinis, Wayne A. Wurtsbaugh, Joseph J. Cech Jr., James Compton Sep 1980

Effect Of Fish Size On Prey Size Selection In Gambusia Affinis, Wayne A. Wurtsbaugh, Joseph J. Cech Jr., James Compton

Watershed Sciences Faculty Publications

Food size selection of the mosquitofish , Gambusia affinis affinis. was measured in aquaria using juvenile stages of the mosquito, Clllex tarsalb;, as prey. Fish size varied from recently born fry to large adult females. Food size selection was positively correlated with fish size. Mosquitofish fry (6-8 111m standard length) attacked and ate primarily first and second instar larvae. Fry attacked larger instars, but attack success on these was low (0 - 50%). Fish larger than 20 mm attached primarily pupae and third and fourth instar larva. No first instar mosquitoes were eaten. Attack success for these fish was above …


Water Quality Aspects Of Coal Transportation By Slurry Pipeline, James W. Moore Aug 1980

Water Quality Aspects Of Coal Transportation By Slurry Pipeline, James W. Moore

Technical Reports

The research program was designed to accomplish three major objectives. These were tot 1) identify and characterize the water quality changes that will occur as a result of the movement of western coal by slurry pipeline; 2) determine the feasibility of utilizing poor (impaired) quality water, such as municipal and industrial effluents, as the slurry medium, and: 3) determine the treatment measures applicable for restoring the slurry wastewater quality to acceptable levels, if required. The focus of the research program was generic rather than specific for any particular pipeline. Consequently, the emphasis was on establishing general ranges of data rather …


A Five Year Water Research Plan For The State Of Arkansas, Robert E. Babcock Aug 1980

A Five Year Water Research Plan For The State Of Arkansas, Robert E. Babcock

Technical Reports

The present economy and quality of life in Arkansas have largely been determined by our natural resources and the way they have been used. Likewise, insuring a sound economic future and a healthful environment in the state will depend on the efficiency and the wisdom with which nature's gifts are managed in the future. As the state's population grows and places new demands on finite resources, the need for effective resource management becomes increasingly critical. Often, a history of plenty can lead to the belated recognition of emerging resource problems. In Arkansas, such is the case with the state's water …


Portable Environmental Data Logger And Sensor, Robert N. Maccallum, R. A. Sims Jun 1980

Portable Environmental Data Logger And Sensor, Robert N. Maccallum, R. A. Sims

Technical Reports

An instrumentation and recording package and several transducers were constructed and used to collect data on the environmental parameters thought to affect wetland vegetation growth and reproduction. These parameters were temperature, humidity, wind velocity, depth of water table, and amount of surface water. The data were collected four times a day and recorded on a magnetic cassette tape that could record for as long as 90 days. The tapes were read and the data were converted to engineering units by a microcomputer-based instrument constructed for that purpose.


Effects Of Changes In Surface Water Regime And/Or Land Use On The Vertical Distribution Of Water Available For Wetland Vegetation: Dynamic Model Of The Zone Of Aeration (Part 1 Of Completion Report For Project A-023-Ark), Robert N. Maccallum, R. A. Sims Jun 1980

Effects Of Changes In Surface Water Regime And/Or Land Use On The Vertical Distribution Of Water Available For Wetland Vegetation: Dynamic Model Of The Zone Of Aeration (Part 1 Of Completion Report For Project A-023-Ark), Robert N. Maccallum, R. A. Sims

Technical Reports

A mathematical model by Green, simulating one-dimensional vertical ground-water movement in unsaturated soils of the prairie region of Kansas, has been adapted for use in a wetlands environment typified by the wetlands forest of Eastern Arkansas. The model consists of two second-order, non-linear, partial differential equations and an algorithm for their numerical solution. The original model was extended to include functions for seasonal changes in transpiration and for drainage of excess precipitation. Before the addition of the two functions, the model reliability was limited to one growth season.


Effects Of Changes In Surface Water Regime And/Or Land Use On The Vertical Distribution Of Water Available For Wetland Vegetation: Portable Environmental Data Logger And Sensors (Part Ii Of Completion Report For Project A-023-Ark), Robert N. Maccallum, R. A. Sims Jun 1980

Effects Of Changes In Surface Water Regime And/Or Land Use On The Vertical Distribution Of Water Available For Wetland Vegetation: Portable Environmental Data Logger And Sensors (Part Ii Of Completion Report For Project A-023-Ark), Robert N. Maccallum, R. A. Sims

Technical Reports

An instrumentation and recording package and several transducers were constructed and used to collect data on the environmental parameters thought to affect wetland vegetation growth and reproduction. These parameters were temperature, humidity, wind velocity, depth of water table, and amount of surface water. The data were collected four times a day and recorded on a magnetic cassette tape that could record for as long as 90 days. The tapes were read and the data were converted to engineering units by a microcomputer-based instrument constructed for that purpose.


Influence Of Las Vegas Wash Density Current On Nutrient Availability And Phytoplankton Growth In Lake Mead, John R. Baker, Larry J. Paulson Jun 1980

Influence Of Las Vegas Wash Density Current On Nutrient Availability And Phytoplankton Growth In Lake Mead, John R. Baker, Larry J. Paulson

Publications (WR)

Density currents are commonly formed in reservoirs because of temperature or salinity induced density differences between inflowing and receiving waters. Anderson and Pritchard (1951) were among the first to demonstrate this in their investigations of density currents in Lake Mead. They found that the Colorado River formed an underflow in Lake Mead during the winter, an overflow in the spring and an interflow in the summer and fall. Wunderlich and Elder (1973) have since described the hydromechanics of these types of flow patterns, and density currents have been reported for several other large reservoirs (Carmack et al. 1979, Johnson and …


Nutrient Interactions Among Reservoirs On The Colorado River, Larry J. Paulson, John R. Baker Jun 1980

Nutrient Interactions Among Reservoirs On The Colorado River, Larry J. Paulson, John R. Baker

Publications (WR)

Interactions among physical, chemical and biological processes in reservoirs can significantly alter the characteristics of the discharge (Neel 1963, Wright 1967, Hannan 1979) that, in turn, can influence the ecology of the river downstream .(Ward and Stanford 1979). Investigations of the Colorado River, system reveal that reservoir-induced changes in the river can also affect downstream reservoirs. The formation of Lake Powell, in 1963 was accompanied by reductions in suspended sediment and nutrient loading and changes in the seasonal temperature and discharge cycles of the Colorado River. In this paper, we evaluate how these changes have influenced the nutrient and trophic …


Dynamic Model Of The Zone Of Aeration, Robert N. Maccallum, R. A. Sims Jun 1980

Dynamic Model Of The Zone Of Aeration, Robert N. Maccallum, R. A. Sims

Technical Reports

A mathematical model by Green (1), simulating one-dimensional vertical ground-water movement in unsaturated soils of the prairie region of Kansas, has been adapted for use in a wetlands environment typified by the wetlands forest of Eastern Arkansas. The model consists of two second-order, non-linear, partial differential equations and an algorithm for their numerical solution. The original model was extended to include functions for seasonal changes in transpiration and for drainage of excess precipitation. Before the addition of the two functions, the model reliability was limited to one growth season. With the mathematical model presented in this work it is possible …