School of Agriculture, Food and Ecosystem Sciences - Theses
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ItemSalinity control, water reform and structural adjustment : the Tragowel Plains Irrigation District(University of Melbourne, 1999)
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ItemNo Preview AvailableEpidemiology of mint rust and variation in the Pathogen, Puccinia menthae Pers(University of Melbourne, 1998)
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ItemNo Preview AvailableGenetics of resistance to Heterodera avenae in Triticum tauschii and its transfer to bread wheat (Triticum aestivum)(University of Melbourne, 1995)
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ItemA genetic evaluation of dystocia in Australian Holstein-friesian cattle(University of Melbourne, 2004)This thesis presents the first large-scale study of the genetic and non-genetic influences on dystocia (calving difficulty) for dairy cows in Australia, and their costs, focusing especially on the Holstein-Friesian breed, but also with some analyses of frequently occurring crossbreeds. Analyses used data collected since 1986, collected by the Holstein-Friesian Association of Australian and the Australian Dairy Herd Improvement Scheme. The calving traits examined were gestation length, calf size, dystocia (measured as any or none, severe or none, and none, slight and severe). I investigated the influence on calving ease of non-genetic variables such as month of calving, cow age or parity, calf sex, and breed of cow and bull. The genetic parameters were estimated: the heritabilities and genetic correlations between traits calculated, separately for primiparous and multiparous, and for sires, maternal grandsires and the maternal effects. Costs associated with dystocia (such as labour costs, loss or fertility, veterinary costs and deaths of cow and or calf) are estimated, and a cost model for dystocia under Australian conditions is proposed. The influence of crossbreeding on calving was investigated, especially with respect to dystocia and calf mortality. Recommendations are made for improving the recording system and the evaluation of bulls, as the sire of calf and as the sire of cow.
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ItemNo Preview AvailableSurvey of the sheep industry in the Western District of Victoria(University of Melbourne, School of Agriculture, 1952?)
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ItemNo Preview AvailableThe role of diffused carbohydrates in the infection of stone fruit by Sclerotinia fructicola (Wint.) rehm(University of Melbourne, 1970)
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ItemSunraysia : a social survey of a dried fruits area(University of Melbourne, 1948)
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ItemNo Preview AvailableObservations on fomes pomaceus (pers.) big. & guill. infecting plum trees ; An investigation of sooty moulds with particular reference to their taxonomy and their growth in culture(University of Melbourne, 1974)I. The Taxonomy of "Sooty Mould "-Fungi. 1. Existing schemes of classification are discussed. 2. A classification is offered in which, the inaccuracies of other taxonomic schemas, are corrected. 3. "Sooty Moulds� are arranged, according to the macroscopic appearance of their growth, into four groups. 4. Diagnostic features are given for five families of ��sooty mould"-genera. 5. The families Capnodiaceae v. Hohn. and Chaetothyriaceae Th. are emended. A key to the identification of the genera Included in each of these families Is given. 6. Chaetothyrium Citri (Arn.) nov. comb. is recorded for the first time in Australia. 7. A new species, Phycopsis australiensis is described. II. An Instigation of the Cultural Behaviour of some "Sooty Mould" Fungi with reference to Climatic Conditions. 1. Eight species which, were isolated from epiphytic moulds, are included in this study. 2. A preliminary survey is made of the nutritional recuirementa of these species. 3. The methods used for recording measurements of colony-size and for calculating the rate of growth are described. 4. Measurement is made of the growth occurring at the following temperatures: 10�C., 15�C., 18�C., 20�C. and 25�C. The optimum growth temperatures determined for seven "sooty mould" endemics lie between 15�C and 20�C. 5. The methods which were adopted for growing these fungi under conditions of controlled atmospheric humidity are described. 6. The humidity growth-rate relations determined here are similar to those of fungi from quite unrelated habitats. 7. The geographic distribution of epiphytic "sooty moulds" is discussed in relation to the temperature and humidity requirements of the species examined here. The temperature-growth relations of the Capnodiaceae species do not confirm the assumption that high temperatures are favourable, rather It would appear that growth is active during the winter months. 8. It la suggested that the deciduous nature of the flora in cool temperate regions is responsible for the almost entire absence of the Capnodiaceae in these regions.
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ItemNo Preview AvailableSelected papers(University of Melbourne, 1972)These selected papers are submitted for examination for the degree of Doctor of Agricultural Science bearing in mind the need to demonstrate that they should constitute - (i) "Substantial published contributions to science applied to some branch of agriculture"; (ii) "Evidence of research and ability satisfactory to the examiners". To this end the papers have been grouped in the following manner. Group I - Papers which collectively provide evidence of the evolution and development of principles and methods for studying land to provide the ecological information needed to determine its capability for various kinds of land-use and so enable better decisions to achieve conservation of natural resources. 1. Soil, land-use and erosion survey around Dookie, Victoria. CSIRO Bull. No. 243, 1949. 2. Soils of the Macquarie Region N.:. . CSIRO Soil Publication No. 4, 1955. 3. Principles and methods of ecological surveys for land-use purposes. Papers for Australian Soils Conference, 1957. 4. Reconnaissance survey of the ecology and land-use in the catchment of the Glenmaggie Reservoir. Soil Conservation Authority Tech. Pubn. No. 1, 1960. 5. A study of the land in north-western Victoria. Soil. Cons. Auth. Tech. Pubn. No. 2, 1963. 6. A study of the land in south-western Victoria. Soil Cons. Auth. Tech. Pubn. No. 3, 1964. 7. The role of humans in land evaluation. CSIRO-UNESCO Symposium on Land Evaluation, Canberra, 1968. Group II - Papers that report results of original research as evidence of contributions to scientific knowledge and its significance as the basis for work by others. 8. The use of the hydrometer for the mechanical analysis of soils. Journ. CSIR Vol. 17, 1944. 9. Tunnelling erosion in north-eastern Victoria. Journ. CSIR Vol. 19, 1946. 10. Studies in the variation of soil reaction - I Field variations at Barooga N.S.W Aust. Journ. Agric. Res. Vol. 2, 1951. 11. Cyclic salt as a dominant factor in the genesis of soils in south-eastern Australia. Aust. Journ. Agric. Res. Vol. 5, 19514. 12. The effect of subterranean clover an Wimmera rye grass in controlling surface run-off from four-acre catchments near Bacchus Marsh, Victoria. Aust. Journ. Exp. Agric. & An. Husb. Vol. 2, 1962. Group III - Papers which indicate the application of a conceptual philosophy of conservation based on ecological principles to tae solution of problems of land-use, soil conservation and agriculture. 13. The Westgate Planning Project. Soil Cons. Auth. Pubn. 1953. 14. Conservation problems on solodic soils in Victoria. Journ. Soil & Water Cons. (USA), Vol. 11, 1956. 15. Land management problems following disturbance of the hydrologic balance of environments in Victoria. Proc. 7th Tech. Meeting IUCN, Athens. 1958. 16. Soil salinity in non-irrigated arable and pastoral land as the result of unbalance of the hydrologic cycle. Proc. UNESCO-Arid hone Symposium on Salinity Problems, Teheran, 1958. 17. The ecology and prevention of soil erosion. Chapter XXX - Biogeography and ecology in Australia. Publishers Junk - The Hague, 1959. 18. The water balance and land-use. Proc. Aust. Acad. Sci. Nat. Symposium on Water Resources, Use & Management. Melb. Univ. Press, 1963. 19. The rehabilitation of degraded land for agricultural and pastoral production. ANZAAS, Canberra, 1964. 20. The correlation of failure of earthen dams with environmental features - Colloquium on Failure of Small Earth. Dams - CSIRO, , 1964. 21. Agrometeorology in relation to the control of soil erosion - United Nations .O. Regional Seminar on Agrorneteorology. Melb., 1966. 22. Dryland farming - principles of applying conservation methods in Australia. T roc. Int. Lech. Dryland Farmg. Conf. - Deere Co. and. F.A.C., oline USA, 1969. Group IV - Papers which collectively demonstrate the extension of the conceptual philosophy of conservation as applied to soil conservation and agricultural problems to those related to tie conservation of all natural resources and its application as a basis for influencing social, political, legal and administrative activities in relation to them. 23. The Victorian High plains - The environment and its use. Proc. Roy. Soc. Vict. Vol. 75, 1962. 24. Soil conservation - ho is responsible? - from Coil conservation in the Pacific - Tenth Pacific Science Congress Series, University of Hawaii Press, 1963. 25. Conservation and the community. Journ. Soil & Water Cons. (USA) Vol. 20, 1965, 26. Nature reserves and National larks in relation to the conservation of man's environment. Aust. Journ. Sci. Vol. 30 196', 27. The conflict between conservation and exploitation of natural resources - Paper to ANZAAS Regional Symposium on The planning and management of Australia's natural resources. Univ. New England, 1967. 28. Soil conservation in Iran - Consultant report to F.A.O., 1967. 29. Resources of East Gippsland - Summary of Symposium - Proc. Roy. Soc. Vict. Vol. 82, 1969. 30. Soil Conservation Law in Australia - Soil. Cons. Authority Pubn., 1970. 31. Criteria for resolving conflict about land-use - Aust. Cons. Found. Seminar on Conservation & Wining, Syd. 1971. 32. Management of conservation reserves - ANZAAS Symposium, Brisbane, 1971.
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ItemNo Preview AvailableProcesses and implications of scald formation on the Eastern Dundas tableland : a case study(University of Melbourne, 2004)This thesis develops an understanding of the processes driving the formation of iron and saline rich scalds in groundwater discharge zones on the Eastern Dundas Tableland. The thesis tests the hypothesis that: The development of land degradation patterns around groundwater discharge zones on the Eastern Dundas Tablelands is not driven by salt concentrations, a consequence of water tables that have risen since European settlement and land clearing, but is the result of the disturbance to the soil environment of discharge zones since land clearing. The research proved the hypothesis correct and identified the transmission of hydrogen sulfide within the groundwater as a key factor in the severity of the degradation. The research also found land clearing may have altered the seasonal flow systems operating within the regolith, which are responsible for the spread of salinity and erosion within primary groundwater discharge zones. The Eastern Dundas Tablelands consist of a fractured rock aquifer, where the unweathered ignimbrites and lavas are hydrologically connected to the overlying regolith. Analyses of groundwater levels, pressures and chemistry indicate the groundwater flow paths to discharge zones increase in length with depth, such that discharge water is sourced from groundwater varying in depth of circulation (up to 150 metres) and flow path length (tens of metres to kilometres). A portion of discharge water flows through the unweathered volcanic aquifer and equilibrates with the rock, becoming reduced. The groundwater flow therefore contains hydrogen sulfide and has reducing capacity. This water then flows preferentially along large scale structures towards discharge zones. The location of groundwater discharge zones is controlled by the intersection between horizontal and sub vertical subsurface structures. Iron and saline rich scalding only occurs where groundwater flow with reducing capacity and containing hydrogen sulphide discharges. Iron and saline scalding is absent where only seasonal groundwater discharge not containing hydrogen sulfide occurs. Measurements of the discharge zones' soil and water EC, Ph and redox potential and the soil chemistry indicate degradation is the result of a combination of processes and is not solely the result of soil salting. Discharge water in wet months is covered by bacteria growth that reduces and oxidises iron and sulfur. During dry periods distinct iron precipitates form crusts on soil surfaces and clog soil pores. Salt efflorescence forms on soil surface and the oxidation of ferrous sulfide creates severe acidity. Evaporation accumulates salts in the discharge zones that are then spread downslope by seasonal break-of-slope discharge. Break of slope discharges erode highly sodic A horizon soils, radially expanding the area of degradation. Relatively constant groundwater levels, historical information and the carbon age of discharge water (2540 years) suggest discharge at the soil surface of the Eastern Dundas Tablelands occurred at least as early as the first records of European settlement. Little to no evidence exists suggest rising groundwater levels, caused by increased recharge since land clearing, have initiated the degradation of discharge zones. The pH, redox potential and measured quantities of ferrous material and sulfur in groundwater suggest iron and saline scalding is initiated by the interaction of the reduced groundwater of the regional groundwater flow and reducible material (iron) in the discharge zone. Prior to the clearing of native vegetation, reduced groundwater flow was able to discharge at the soil surface without coming into contact with reducible material (iron). Any hydrogen sulfide in discharge water was able to dissipate into the atmosphere, removing the reducing capacity of the water. Since clearing, iron has been redistributed into groundwater flow paths. Iron is reduced by the groundwater flow before the hydrogen sulfide is able to dissipate with ferrous and iron sulfide rich minerals forming within discharge zones. Upon oxidation, iron rich precipitates (ferrihydrite and schwertmannite) form in soil pores and along the soil surface with the oxidation of ferrous sulfide creating severe acidity (pH <4). The degree of degradation is directly related to the rate and volume of groundwater discharge. The least degraded areas coincide with point-flowing springs, the wettest areas of iron and saline scalds. Within point flowing springs, permanent saturation prevents the oxidation of ferrous sulfide material, the formation of iron crust and the accumulation of salts via evaporation. The most severe degradation coincides with areas of diffuse discharge, where the drying of the soil surface leads to iron precipitate formation, salt accumulation and severe acidity as ferrous sulfide material oxidises. The process of iron and saline rich scalding can be halted, and the area remediated if: � reducible material is removed from the groundwater discharge zone, preventing the reduced groundwater from mobilising iron and forming iron-sulfide material; and � the discharge zone is fully submersed in water, such as a dam. In this case, groundwater hydrogen sulfide will dissipate into the atmosphere, removing the reducing capacity of groundwater discharge.