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Articles 151 - 169 of 169

Full-Text Articles in Life Sciences

Evaluation Of A Pelleted Bait Containing Methyl Anthranilate As A Bird Repellent, J. Russell Mason, Larry Clark, Timothy Miller Jan 1993

Evaluation Of A Pelleted Bait Containing Methyl Anthranilate As A Bird Repellent, J. Russell Mason, Larry Clark, Timothy Miller

Larry Clark

No-till agriculture involves the use of granular pesticide formulations, chemically treated seeds, and pelleted baits. Some of these may accidentally kill birds. We have tested whether methyl anthranilate (MA), a known bird repellent, would eliminate consumption of a pelleted bait. In two laboratory experiments and an outdoor aviary trial, cowbirds (Molothrus ater Bodd.) were presented with pellets containing pesticide and MA, pellets containing pesticide but no MA, and carrier pellets without pesticide or MA. Consumption of any formulation was low, but the addition of MA significantly decreased bait loss in the laboratory, and prevented the disappearance of bait in the …

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White Plastic Flags Repel Snow Geese, J. Russell Mason, Larry Clark, N. Jay Bean Jan 1993

White Plastic Flags Repel Snow Geese, J. Russell Mason, Larry Clark, N. Jay Bean

Larry Clark

The effectiveness of white flags as visual repellents to snow geese (Chen caerulescens) was evaluated. Twelve fields, each 10.12 ha (25 acres) in area, with snow goose damage, were located and proximity was used to create six pairs. Within each pair, one field was selected randomly for treatment (one white plastic flag per acre) and the other served as a control. At 7-day intervals for SV2 weeks, mean vegetation length and mean percentage vegetative cover were estimated for all fields. The results showed that grazing damage was significantly reduced in fields with flags. It is concluded that white plastic flags …

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Addition Of Gel-Forming Hydrophilic Polymers To Nitrogen Fertilizer Solutions, Robert Mikkelsen, A David Behel Jan 1993

Addition Of Gel-Forming Hydrophilic Polymers To Nitrogen Fertilizer Solutions, Robert Mikkelsen, A David Behel

Robert Mikkelsen

Environmental and economic concerns are causing a search for more effective fe rtilizer products and improved methods for managing existing fertilizers. This laboratory and greenhouse study was conducted to determine if the addition of gel-forming hydrophilic polymers to N fertilizer solutions could reduce N leaching loss and increase plant uptake of N. In the first experiment, a solution of urea ammonium nitrate (UAN, 32% N) was mixed with a variety of polymers at three concentrations, band applied to a sandy soil, and leached weekly for six weeks. Nitrogen leaching losses were reduced from 0 to 45% during the first four …

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Controlled-Release Fertilizers To Increase Efficiency Of Nutrient Use And Minimize Environmental Degradation - A Review, Avi Shaviv, Robert Mikkelsen Jan 1993

Controlled-Release Fertilizers To Increase Efficiency Of Nutrient Use And Minimize Environmental Degradation - A Review, Avi Shaviv, Robert Mikkelsen

Robert Mikkelsen

Total world consumption of fertilizer N, P2 O5, and K2O in 1990 / 1991 was 78. 37. and 26 million tons per annum respectively, with a projected yearly increase of demand of about 2 to 3% . Trends in crop production (maize and wh eat) in the last four decades s how that N application rates increased about 15 times whereas its accumulation in grain increased only 3 to 4 times. At the same time nutrient recovery by crops remained relatively low (e .g. a bout 50% for N). This represents a potentially alarming situation from environmental, economic and resource …

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Chemical Repellency In Birds: Relationship Between Chemical Structure And Avoidance Response, Larry Clark, Pankaj Shah, Russell Mason Jan 1991

Chemical Repellency In Birds: Relationship Between Chemical Structure And Avoidance Response, Larry Clark, Pankaj Shah, Russell Mason

Larry Clark

We examined how molecular structure of24 anthranilate and benzoic acid deriva­ tives correlated with drinking behavior in European starlings Sturnus vulgaris.The effectiveness of bird repellents was &?SOciated with basicity, the presence of an electron onating group in resonance with an electron-withdrawing carboxylic group on a phenyl ring, and a heterocyclic ring in the same pi cloud plane as the phenyl ring. Of the benzoic acid derivatives tested in this study, methyl, ethyl, dimethyl, and linalylanthranilate as well as anthranilic acid and 4-ketobenztriazine were repellent to birds. Water consumption was significantly reduced relative to control levels at concentrations as low as …

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The Effect Of Selenium On Sulfur Uptake By Barley And Rice, Robert Mikkelsen, Hongfu Wan Jan 1990

The Effect Of Selenium On Sulfur Uptake By Barley And Rice, Robert Mikkelsen, Hongfu Wan

Robert Mikkelsen

Because of their chemical and physical similarities, plant uptake of sulfur and selenium are closely related. Barley and rice were grown in greenhouse solution culture to examine the synergistic interactions between sulfate and selenate in plant uptake. In the presence of low concentrations of solution sulfate, shoot and root yields were decreased with additions of selenate. However, when sulfate was present in elevated concentrations, no selenium-induced yield reductions occurred. A synergistic interaction between sulfate and selenate caused an increase in the shoot sulfur concentrations with increasing concentrations of selenate at low sulfate solution concentrations. At elevated sulfate concentrations, no synergism …

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Biuret In Urea Fertilizer, Robert Mikkelsen Jan 1990

Biuret In Urea Fertilizer, Robert Mikkelsen

Robert Mikkelsen

Urea has become the leading form of N fertilizer worldwide. Historically there has been concern about biuret formed during the manufacturing of urea fertilizer and the potential adverse effect of biuret on plant growth. In this paper, the fate of biuret in soils and its phytotoxicity is reviewed. Biuret is mineralized by many soil micoorganisms, but the process is much slower than for urea. Excessively high biuret concentrations can damage seedlings and, like urea, should not be placed in close proximity to germinating seeds. Crop tolerance to biuret varies according to the plant species, soil conditions, fertilizer placement, and method …

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Phosphorus Fertilization Through Drip Irrigation, Robert Mikkelsen Jan 1989

Phosphorus Fertilization Through Drip Irrigation, Robert Mikkelsen

Robert Mikkelsen

Although P fertilization through drip irrigation systems has not been widely recommended, a review of currently available literature indicates this fertilizer application technique can offer many advantages when performed properly. Using drip irrigation to apply P fertilizer allows nutrient placement directly into the plant root zone during critical periods of nutrient demand. Less P fertilizer is generally required to achieve sufficient tissue P concentrations and equivalent yields when it is drip-applied than with other application methods. The distribution of drip-applied P in soil depends on soil properties, the source of P fertilizer, the rate of application, and the amount of …

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Factors Affecting Selenium Accumulation By Agricultural Crops, Robert Mikkelsen, Albert L. Page, Frank T. Bingham Jan 1989

Factors Affecting Selenium Accumulation By Agricultural Crops, Robert Mikkelsen, Albert L. Page, Frank T. Bingham

Robert Mikkelsen

The accumulation of selenium by plants is of concern worldwide. Many regions grow crops that contain insufficient Se to meet animal nutritional requirements. In these locations with low Se, efforts have been made to increase tissue Se concentrations. Other areas have problems with excessive Se found in vegetation grown on seleniferous soils. Plant species vary in their ability to accumulate and tolerate Se. Selenium accumulator plants can accumulate extremely high Se concentrations (several thousand mg Se kg-1) when grown in seleniferous soils, whereas typical agricultural crops have a much lower Se tolerance (<50 mg Se kg>-1 ). It has been suggested that …

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Forest Gardens Of The Maya, David A. Bainbridge Jan 1988

Forest Gardens Of The Maya, David A. Bainbridge

David A Bainbridge

The lowland Maya supported very high populations in an area with limited water and soil. Much can be learned from studying their sophisticated management practices. Forest gardens and agroforestry helped provide key nutrients, materials, and inputs for improved soil.

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Use Of Acorns For Food In California: Past, Present, Future, David A. Bainbridge Jan 1987

Use Of Acorns For Food In California: Past, Present, Future, David A. Bainbridge

David A Bainbridge

Acorns are a neglected food for people, livestock, domestic fowl, and wildlife in California. Acorns are easy to collect, store, and process. In addition to the nutritious nut and meal, acorns yield an oil comparable in quality and flavor with olive oil. The existing acorn market could be greatly expanded and provide new income for rural people. A serious effort to identify and propagate the best oak acorn cultivars for these products is long overdue. It is particularly appropriate for this research to be done in California, which once had an acorn based economy.

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Application Of Urea Phosphate And Urea Sulfate To Drip-Irrigated Tomatoes Grown In Calcareous Soil, Robert Mikkelsen, Wesley Jarrell Jan 1987

Application Of Urea Phosphate And Urea Sulfate To Drip-Irrigated Tomatoes Grown In Calcareous Soil, Robert Mikkelsen, Wesley Jarrell

Robert Mikkelsen

The potential benefit of acid applied through drip urrigation on soil nutrient availability, plant nutrition, and yield was studied. Tomatoes (Lycopersicon esculentum Mill., cv. Better Boy) were grown in a P-deficient calcareous loam soil in 114-L plastic-lined cans. Phosphorus was added weekly through drip irrigation as urea phosphate (UP) (17-19-0) at four concentrations (0, 20, 40, 80 kg P/ha). Two other treatments entailed 40 kg P/ha soil-banded triple superphosphate (TSP) (0-20-0) with or without the addition of drip­ applied urea sulfate (US) (15-0-0-16). Urea sulfate was added at the rate equivalent to the titratable acidity of the 40 kg UP-P/ha …

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Tva Fluid Fertilizers Chapter Two - Agronomic Aspects, Eugene C. Sample, Gary W. Akin, Robert Mikkelsen Jan 1984

Tva Fluid Fertilizers Chapter Two - Agronomic Aspects, Eugene C. Sample, Gary W. Akin, Robert Mikkelsen

Robert Mikkelsen

No abstract provided.

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Tva Fluid Fertilizers Chapter One- History, Growth, And Status, Robert Mikkelsen Jan 1984

Tva Fluid Fertilizers Chapter One- History, Growth, And Status, Robert Mikkelsen

Robert Mikkelsen

No abstract provided.

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Tva Fluid Fertilizers Chapter Four - Chemical Properties, A W. Frazier Jan 1984

Tva Fluid Fertilizers Chapter Four - Chemical Properties, A W. Frazier

Robert Mikkelsen

No abstract provided.

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Tva Fluid Fertilizers Chapter Five - Production, Handling, And Use Of Anydrous Ammonia And Status, G. M. Blouin, H. L. Kimborough, W. J. Sharratt Jan 1984

Tva Fluid Fertilizers Chapter Five - Production, Handling, And Use Of Anydrous Ammonia And Status, G. M. Blouin, H. L. Kimborough, W. J. Sharratt

Robert Mikkelsen

No abstract provided.

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Greenhouse Techniques For Soil-Plant-Fertilizer Research, S E. Allen, G L. Terman, L B. Clements, Robert Mikkelsen May 1976

Greenhouse Techniques For Soil-Plant-Fertilizer Research, S E. Allen, G L. Terman, L B. Clements, Robert Mikkelsen

Robert Mikkelsen

PART 2: Special problems and procedures Principles of nutrient uptake in pot experiments

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Greenhouse Techniques For Soil - Plant - Fertilizer Research, S E. Allen, G L. Terman, L B. Clements, Robert Mikkelsen May 1976

Greenhouse Techniques For Soil - Plant - Fertilizer Research, S E. Allen, G L. Terman, L B. Clements, Robert Mikkelsen

Robert Mikkelsen

PART 3: Design & sample calculaitons for specific types of experiments Typical greenhouse report References

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Greenhouse Techniques For Soil-Plant-Fertilizer Research, S E. Allen, G L. Terman, L B. Clements, Robert Mikkelsen May 1976

Greenhouse Techniques For Soil-Plant-Fertilizer Research, S E. Allen, G L. Terman, L B. Clements, Robert Mikkelsen

Robert Mikkelsen

PART 1: Introduction Greenhouse facilities General techniques

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