School of Agriculture, Food and Ecosystem Sciences - Theses
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ItemPhysical properties of some Victorian soils( 1958?)The study of soil physics is now recognised as an important aspect of agriculture. The maintenance of crumb structure in wheat soils, increasing the infiltration rate on land liable to erosion, the subsurface drainage of horticultural soils, the supply of adequate moisture to irrigated crops, and the prevention of seepage from rice fields are examples of the necessity for understanding the physics of soil. Methods of measurement of such properties are now available to give a reliable picture, and some of these are reported in the first part of this paper for several Victorian soils - there is indeed a lack of such information. However there is a greater deficiency in the understanding of the fundamental reasons of why a soil has the physical properties that it displays. Subsoil permeability has been investigated and is reported on and discussed in the second part of the paper.
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ItemAn investigation of potato gangrene in Victoria : including the identification and comprehensive study of the causal organism, Phoma foveata Foister and a comparison of the Scottish and Victorian isolates with P. eupyrena Sacc., P. solanicola Prill et Del. and Phomopsis tuberivora Guss et Fost( 1957?)In October 1963 attention was drawn to the possibility of an hitherto unknown storage disease of potatoes in Victoria. Diseased tubers if the variety ton ware brought to the Plant Research Laboratory, Burnley, from a property at Clarke's Hill, via Ballarat, and a pycnidial-forming fungus was isolated consistently from lesions by Anderson (1953). Later that month, apparently identical isolates were obtained from diseased tubers of two other varieties which were received from the same property. In consequence, an investigation of dry rots in storage was commenced in September, 1954. One of the original objectives was to determine whether this pycnidial-forming fungus was a causal organism of tuber rot. As the investigation proceeded, it became evident that the fungus in question was responsible for a particular type of rot. In other countries similar types of tuber disease have been attributed to species of the Phomaceae. In the detailed study that followed, attempts were made to identify Victorian isolates with, or to distinguish them from, some of these other storage pathogens. As a result of the investigation, the pycnidial forming fungus has been identified as Phoma foveats Foister.. This fungus is responsible for the disease known as Gangrene of tubers in the British Isles. It has not been recorded previously outside that area. Although most of the work described in this report is laboratory in nature, one of the main aims has been to collect information which may may assist in determining an approach to the control of the disease.
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ItemStudies on the development, activity, and longevity, of the Queensland fruit fly, Strumeta tryoni (Froggatt) and evidence of a cold-hardy Victorian race( 1956)Following the discovery of the Queensland fruit fly, Strumeta tryoni (Froggatt), in Eastern Victoria, a laboratory was set up in 1949 at Bairnsdale for the purpose of studying the fly under controlled conditions, and as a centre from which to carry out field observations. Previous work on S. tryoni in the northern states of Australia had been mainly in the field and concerned with the life history of the fly, with its control by sprays and baits, and with luring methods. In Victoria, the problem was rather different as the possibility of completely eradicating the fly was being considered, and very little was known of its habits or of its life history under Victorian conditions. The original objectives of the investigation were:- To determine the extent of S. tryoni infestation in East Gippsland, Victoria. To study the distribution and fruiting periods of wild plants which are hosts for S. tryoni. To study the life history of S. tryoni under laboratory and under field conditions. Field work included the setting up and replenishing of lure pots hung in wild and in cultivated fruiting plants in districts throughout East Gippsland, the collecting of large numbers of wild fruits, and field cage studies in some districts. Although much time was spent in collecting fruits and maintaining lures throughout the investigation, it became apparent as the work proceeded, that laboratory studies were likely to yield more additional information than were continuous field investigations, as the fly population in East Gippsland was so low that it was difficult to obtain infested wild fruits or to lure many flies. The greater part of this report is, therefore, concerned with a study of the life history of S. tryoni and with laboratory experiments, including the effect of environmental factors during the larval, pupal and adult stages.