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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Potential impacts of interception belts on the management of dryland salinity / submitted by Peter John Taylor.

Taylor, Peter John, 1957- January 1999 (has links)
Bibliography: p. 161-185. / xii, 185 p. : ill. (some col.), map ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The main aim of this project was to establish whether or not interception belts can be expected to transpire sufficient volumes of water to be considered a feasible option for controlling rising groundwater. (conclusion) / Thesis (Ph.D.)--University of Adelaide, Dept. of Agronomy and Farming Systems, 1999
2

Potential impacts of interception belts on the management of dryland salinity

Taylor, Peter John, 1957- January 1999 (has links) (PDF)
Bibliography: p. 161-185. The main aim of this project was to establish whether or not interception belts can be expected to transpire sufficient volumes of water to be considered a feasible option for controlling rising groundwater. (conclusion)
3

Ecology and management of weeds under no-till in southern Australia

Chauhan, Bhagirath Singh January 2006 (has links)
No - till systems have been widely adopted by farmers in Australia over the past decade to reduce soil erosion, improve soil physical and chemical properties, conserve soil moisture and save on fuel costs. These changes in tillage practices can have a major influence on the ecology and management of weeds. Studies were undertaken on the seed biology of six important Australian weed species to provide underpinning knowledge of their response to tillage. Field studies were also undertaken to investigate the effect of no - till on weed seedling emergence, seed bank persistence and herbicide behaviour. Seed germination of threehorn bedstraw and wild turnip, the latter only at sub - optimal temperatures, was inhibited by light. In contrast, seed germination of common sowthistle and Indian hedge mustard was stimulated by light. Seed germination of small - flowered mallow was not influenced by the light conditions. Seedling emergence of threehorn bedstraw, wild turnip, small - flowered mallow and annual ryegrass was low on the soil surface but increased with shallow burial, which suggests that farming practices that achieve shallow burial of seeds are likely to promote greater seedling emergence of these weed species. In contrast, seedling emergence of common sowthistle and Indian hedge mustard was greatest for the seeds present on the soil surface and emergence decreased with increased burial depth. In field experiments, low soil disturbance tillage systems left more seeds on the soil surface after crop sowing, whereas high soil disturbance systems buried most of the seeds. Seedling emergence of annual ryegrass, threehorn bedstraw and wild radish was greater under minimum tillage than no - till system. In contrast, seedling emergence of Indian hedge mustard, common sowthistle, silvergrass, small - flowered mallow and turnipweed was greater under the no - till system. Seedling emergence of wild oat and wild turnip was not influenced by the tillage system. Even though seedling emergence of annual ryegrass was much lower under no - till, the persistence of residual viable seeds of annual ryegrass from one season to the next was similar between the tillage systems. This was because of much greater seed decay under no - till ( 48 to 60 % ) than that recorded under minimum tillage ( 12 to 39 % ). All dinitroaniline herbicides ( trifluralin, pendimethalin and oryzalin ) were more effective in reducing the number of plants, spikes, dry matter and seed production of annual ryegrass when incorporated at sowing with tines than with the discs. At Minlaton in 2004 and 2005, bioavailable trifluralin was greater under tillage systems with greater levels of soil disturbance than under lower soil disturbance systems. In the absence of the herbicide, annual ryegrass was less competitive with wheat under the disc - sown systems. The response of grain yield to herbicides was greater under the tine - sown systems than the disc - sown systems. The performance of S - metolachlor on annual ryegrass control was investigated under no - till. The control of annual ryegrass was greater than 80 % when S - metolachlor was applied at sowing ( incorporated by sowing or post - sowing pre - emergence ). However, application of the herbicide at sowing resulted in phytotoxic effects on crop emergence and grain yield of wheat. Application of S - metolachlor at 20 or 23 days before sowing not only provided effective control ( 74 to 83 % ) of annual ryegrass, it was also safe on wheat. Application of this herbicide at 40 or 46 days before sowing was relatively ineffective in controlling annual ryegrass ( 33 to 49 % weed kill ) but safe on wheat. In conclusion, soil disturbance caused by tillage was found to have a major influence on the behaviour of the seed bank of different species including seedling emergence and decay rates of weed seeds. However, the response to tillage tended to be species - specific and was related to their seed biology. Tillage systems also had a major influence on the efficacy and bioavailability of trifluralin, which is prone to volatilisation losses. The findings of this research program are expected to contribute to the improvement in weed management under no - till systems. / Thesis (Ph.D.)--School of Agriculture, Food and Wine, 2006.
4

Ecology of wild radish (Raphanus raphanistrum) : crop-weed competition and seed dormancy.

Eslami, Seyed Vahid January 2006 (has links)
Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / Field experiments investigating the nature and extent of interference in monocultures and mixtures of wild radish and wheat were conducted in 2003 and 2004 at Roseworthy, South Australia. Intraspecific and interspecific interfenernce between wild radish and wheat was investigated in the field using additive series design. Results indicated that higher densities of wheat were able to suppress seed production of this weed species. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1274618 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2006
5

Susceptibility of the black Portuguese millipede, "Ommatoiulus moreletti" Lucas (Diplopoda : iulidae) to insecticides

Kassebaum, B. J. January 1985 (has links) (PDF)
Some ill. mounted. Bibliography: leaves 179-185.
6

The ecology of Melangyna viridiceps and Simosyrphus grandicornis (Diptera : Syrphidae) and their impact on populations of the rose aphid, Macrosiphum rosae

Soleyman-Nezhadiyan, Ebrahim. January 1996 (has links) (PDF)
Bibliography: leaves 213-233. This thesis studies the influence of the two common syrphid species on populations of rose aphids in rose gardens in Adelaide. The study determines whether the provision of attractive flowers increases the suppressive effect of syrphids on rose aphids and analyses some ecological and biological aspects of two syrphid species -- Melangyana viridiceps (Macquart) and Simosyrphus grandicornis (Macquart) -- in a Mediteranean climate to obtain a better understanding of their biological control potential.
7

Integrated strategies for wild oat (Avena spp.) management in southern Australian farming systems

Nietschke, Brett Steven. January 1997 (has links) (PDF)
Bibliography: leaves 128-146. Study was undertaken to determine the occurence and species incidence of wild oats in a major cropping region of southern Australia. Population dynamic studies were undertaken at two sites to define the seed bank decline and emergence pattern of several wild oat populations over a three year period. Management studies were conducted to determine appropriate strategies for the control of wild oats in southern Australian farming systems.
8

The ecology of Melangyna viridiceps and Simosyrphus grandicornis (Diptera : Syrphidae) and their impact on populations of the rose aphid, Macrosiphum rosae / by Ebrahim Soleyman-Nezhadiyan.

Soleyman-Nezhadiyan, Ebrahim January 1996 (has links)
Bibliography: leaves 213-233. / xiii, 255 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis studies the influence of the two common syrphid species on populations of rose aphids in rose gardens in Adelaide. The study determines whether the provision of attractive flowers increases the suppressive effect of syrphids on rose aphids and analyses some ecological and biological aspects of two syrphid species -- Melangyana viridiceps (Macquart) and Simosyrphus grandicornis (Macquart) -- in a Mediteranean climate to obtain a better understanding of their biological control potential. / Thesis (Ph.D.)--University of Adelaide, Dept. of Crop Protection, 1997
9

Woolly apple aphid : interactions within an orchad system

Fitzgibbon, Frances, 1954- January 1996 (has links) (PDF)
Errata and addenda attached. Bibliography: leaves 195-211. This thesis is concerned with the biology of Eriosoma lanigerum (WAA) and its parasitoid (Aphelinus mali), the impact of the pest on the crop and the effects of pesticides used routinely in South Australian orchards on both woolly apple aphid and the parasitic wasp. The study identifies current management practices of apple growers in South Australia. Aspects of the biology of WAA and A.mali are examined. Work is also done on the toxicity against WAA and A.mali of insecticides used in the control of codling moth and phytophagous mites. The effects of WAA infestation on the growth of young trees are investigated. The seasonal activity of WAA on mature trees is determined over a two season period.
10

Woolly apple aphid : interactions within an orchad system / by Frances Fitzgibbon.

Fitzgibbon, Frances, 1954- January 1996 (has links)
Errata and addenda attached. / Bibliography: leaves 195-211. / xviii, 211 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis is concerned with the biology of Eriosoma lanigerum (WAA) and its parasitoid (Aphelinus mali), the impact of the pest on the crop and the effects of pesticides used routinely in South Australian orchards on both woolly apple aphid and the parasitic wasp. The study identifies current management practices of apple growers in South Australia. Aspects of the biology of WAA and A.mali are examined. Work is also done on the toxicity against WAA and A.mali of insecticides used in the control of codling moth and phytophagous mites. The effects of WAA infestation on the growth of young trees are investigated. The seasonal activity of WAA on mature trees is determined over a two season period. / Thesis (Ph.D.)--University of Adelaide, Dept. of Crop Protection, 1997

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