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Application Of Advanced Algorithms And Statistical Techniques For Weed-Plant Discrimination, Saman Akbar Zadeh

Theses: Doctorates and Masters

Precision agriculture requires automated systems for weed detection as weeds compete with the crop for water, nutrients, and light. The purpose of this study is to investigate the use of machine learning methods to classify weeds/crops in agriculture. Statistical methods, support vector machines, convolutional neural networks (CNNs) are introduced, investigated and optimized as classifiers to provide high accuracy at high vehicular speed for weed detection.

Initially, Support Vector Machine (SVM) algorithms are developed for weed-crop discrimination and their accuracies are compared with a conventional data-aggregation method based on the evaluation of discrete Normalised Difference Vegetation Indices (NDVIs) at two different …

Local Binary Pattern Based Algorithms For The Discrimination And Detection Of Crops And Weeds With Similar Morphologies, Vi Nguyen Thanh Le

Theses: Doctorates and Masters

In cultivated agricultural fields, weeds are unwanted species that compete with the crop plants for nutrients, water, sunlight and soil, thus constraining their growth. Applying new real-time weed detection and spraying technologies to agriculture would enhance current farming practices, leading to higher crop yields and lower production costs. Various weed detection methods have been developed for Site-Specific Weed Management (SSWM) aimed at maximising the crop yield through efficient control of weeds. Blanket application of herbicide chemicals is currently the most popular weed eradication practice in weed management and weed invasion. However, the excessive use of herbicides has a detrimental impact …

Investigating Optimum Wavelength(S) For Growth Of Lactuca Sativa, L. Using Tunable Led Sources And Developing Thin-Film Filters For Glass Greenhouses, Jacqualine Anne Thomas

Theses: Doctorates and Masters

With the increase in world population, the continued advances in modern greenhouse agriculture and plant growth practices are expected to help overcome the global problem of future food shortages. This research investigates a way to assist in stemming the problem of food shortage by using optimised light irradiation (within the constraints of the experiment) on a sample plant species of lettuce (Lactuca sativa, L.). Whilst lettuce is often grown in hydroponic systems, the current research is conducted in stand-alone pots with hand watering, due to the requirements of health and safety and available resources.

The experiments were designed …

Seedling Xylem Anatomy Of Two Banksia Species Relative To Availability Of Groundwater, Melissa Karlinski

Theses: Doctorates and Masters

Fluctuating environmental conditions place plants at risk of mortality if they cannot adapt, particularly to warmer temperatures and drier environments. Plants are known to modify their morphology, physiology and anatomy to thrive under these conditions, and xylem anatomy and hydraulic architecture are common traits studied to understand plant adaptations and responses to changeable water availability. However, little is known about the changes to the hydraulic architecture of groundwater dependent plants during their early establishment in water-limited environments. By exposing young seedlings of two Banksia species to contrasting groundwater availability treatments in a glasshouse experiment, it was possible to analyse the …

Influence Of Micropropagation On The Ontogenetic Phases Of Paulownia, Michael Pezzaniti

Theses: Doctorates and Masters

The aim of this research was to examine whether the method of micropropagation and tissue source affects the early growth and development of Paulownia in the first six months following transfer from tissue culture and establishment in soil. This tree species was chosen as it is a fast growing, short-rotation timber tree and able to adapt successfully to new environments. It is easily established in vitro and has been micropropagated using a range of different techniques. Three methods of micropropagation were chosen: callus regeneration, somatic embryogenesis and the third method was inducing root suckers in vitro. The third method …

Ecology Of Savanna Ecosystems In Indonesia, Sutomo

Theses: Doctorates and Masters

Tropical savannas in South East Asia are important yet understudied ecosystems. In fact, the description of savanna is limited in the Indonesian Archipelago, a region which, based on climate alone, would be expected to have mostly forest. In this thesis, I compared and contrasted the vegetation characteristics of four savannas in the wetter part of the Indonesian archipelago (Java – Bali – Lombok) to understand how fire and grazing influence their dynamics, and searched for evidence of savanna origins, maintenance, invasion by exotic/woody species and possible ecosystem transitions. Vegetation surveys, remote sensing techniques and statistical models were used to spatially …

Identifying Plant Functional Traits To Assist Ecological Intervention In A Drying Landscape, Ana Luiza Muler

Theses: Doctorates and Masters

Mediterranean-type ecosystems (MTEs) are among the most vulnerable to land use and climate change and many attempts are in place to restore these ecosystems. Therefore, it is necessary to assess differences in plants’ ability to withstand water-stress, including biotic interactions. Such knowledge helps us understand community assembly, which is crucial for ecological intervention. This study involved: (1) reviewing the literature on traits that can differentiate functional types; (2) adapting the methodology to measure leaf water potential at turgor loss point (πtlp) for small-leaved species; (3) using these traits to quickly identify water-use strategies of adult …

A Neuro-Genetic Hybrid Approach To Automatic Identification Of Plant Leaves, Oluleye Hezekiah Babatunde

Theses: Doctorates and Masters

Plants are essential for the existence of most living things on this planet. Plants are used for providing food, shelter, and medicine. The ability to identify plants is very important for several applications, including conservation of endangered plant species, rehabilitation of lands after mining activities and differentiating crop plants from weeds.

In recent times, many researchers have made attempts to develop automated plant species recognition systems. However, the current computer-based plants recognition systems have limitations as some plants are naturally complex, thus it is difficult to extract and represent their features. Further, natural differences of features within the same plant …

Analysis Of Plant Analytes Using Capillary Electrophoresis And High Performance Liquid Chromatography, Umme Kalsoom

Theses: Doctorates and Masters

Plants contain an enormous array of organic and inorganic components, the analysis for which may involve a wide range of methods. The focus of this study was to develop high performance liquid chromatography and capillary electrophoresis methods for the analysis of three classes of analytes: osmoregulants, minerals and amino acids.

Firstly, this study explored the potential of capillary electrophoresis for the analysis of three very common osmoregulants (proline, glycine betaine and mannitol). A diverse array of methods has been reported for determining each of these analytes, however, the literature on osmoregulants and their analysis is quite disjointed and traverses both …

Fate Of Eucalyptus Marginata Seed From Canopy-Store To Emergence In The Northern Jarrah Forests Of Western Australia: Research To Help Improve Regeneration Following Shelterwood Treatment, Jeffrey Cargill

Theses: Doctorates and Masters

The establishment of seedling regeneration is a key process in and indicator of ecologically sustainable forest management. The availability of seed and the creation of a suitable seedbed are recognised as important factors limiting seedling recruitment. A silvicultural method commonly used across northern and eastern jarrah forest blocks is shelterwood cutting. The primary objective of treating jarrah forest to shelterwood is to promote seedling regeneration in areas lacking sufficient advanced growth. Despite the widespread and progressive implementation of the shelterwood method, its application in jarrah forest has shown varying degrees of success.

This thesis sought to investigate and better understand …

Development Of An Optical Sensor For Real-Time Weed Detection Using Laser Based Spectroscopy, Arie Jacobus Paap

Theses: Doctorates and Masters

The management of weeds in agriculture is a time consuming and expensive activity, including in Australia where the predominant strategy is blanket spraying of herbicides. This approach wastes herbicide by applying it in areas where there are no weeds. Discrimination of different plant species can be performed based on the spectral reflectance of the leaves. This thesis describes the development of a sensor for automatic spot spraying of weeds within crop rows. The sensor records the relative intensity of reflected light in three narrow wavebands using lasers as an illumination source.

A prototype weed sensor which had been previously developed …

Verticordia Micropropagation Through Direct Ex Vitro Rooting, Belinda Delaney

Theses: Doctorates and Masters

The objective of this study was to improve the existing shoot multiplication protocol for Verticordia grandis (McComb, Arthur & Newll, 1986; Newell, Growns & McComb, 2005) and to investigate and establish reliable root induction and acclimatisation protocols to enhance survival of micropropagated plantlets. It was envisaged that these protocols would be successful in micropropagation, growth and survival of different V. grandis clones and possibly applicable to other Verticordia species.

The elongation of in vitro Verticordia shoots on multiplication media was improved by reducing the concentration of BAP from 1μM to 0.25 μM, which resulted in a more uniform shoot length …

The Response Of Banksia Roots To Change In Water Table Level In A Mediterranean-Type Environment, Caroline Canham

Theses: Doctorates and Masters

For phreatophytic plants to persist in a given habitat they need to maintain a functional connection to the water table, and the capacity for roots to respond to changes in the water table is a key aspect of this. If root growth is limited by season, plants may not be able to grow roots to adjust to changes in the water table at a particular time of the year. The redistribution of roots, particularly the capacity for roots to follow the water table down in summer and autumn months, is vital for phreatophytic plants to maintain a functional connection with …

The Effect Of Irrigation On Soil Water Availability And The Plant Water Relations Of Three Species Growing On Revegetated Bauxite Residue Disposal Areas, Sharyn Burgess

Theses : Honours

The waste product resulting from the alumina refining process consists of residue sand and mud which is laid on bauxite residue disposal areas (RDAs). Once the RDAs have been effectively solar dried they are revegetated to minimise deep drainage and potential groundwater contamination. In this study, two RDAs located at Alcoa's Pinjarra refinery were seasonally monitored to determine the effects of irrigation on soil water availability and plant water use. Three experimental Blocks were established by Alcoa, each with an irrigated and unirrigated site. Since then, irrigation has been applied to the three treated sites to maintain the root zone …

Water Stress Vulnerability Of Four Banksia Species In Contrasting Ecohydrological Habitats On The Gnangara Mound, Western Australia, Caroline Canham

Theses : Honours

The distribution of obligate and facultative phreatophytic vegetation reflects the gradient of ecohydrological habitats in a landscape. Preliminary investigations of Banksia vulnerability to xylem embolism have reported that obligate phreatophytes are more susceptible to water stress than facultative phreatophytes (Froend & Drake 2006). A quantitative measure of plant susceptibility to water stress is vital when establishing environmental water requirements. This study investigated interspecific differences in vulnerability to water stress for two facultative phreatophytes (B. attenuata and B. menziesii) and two obligate pln·eatophytes (B. ilicifolia and B. littoralis) at the same position along an ecohydrological gradient on the Gnangara Groundwater Mound, …

The Effects Of Light Reduction Treatments On Mobile Epifaunain An Amphibolis Griffithii (Black) Den Hartog Seagrass Ecosystem, Helen Barwick

Theses : Honours

One of the main anthropogenic disturbances to seagrass meadows in Australia is reduction in light availability, through nutrient enrichment or suspended sediments. Dredging can create suspended sediment plumes from the expulsion of particulates into the water column and in tum reduces light penetration to seagrass ecosystems. Preliminary investigations have demonstrated that light reduction for different intensities and durations results in reduced seagrass and epiphytic algae biomass. The main aim of this study was to determine the effects of different intensities and durations of light reduction on epifaunal assemblages in Amphibolis griffithii seagrass meadows in Jurien Bay, Western Australia. This was …

Genetic Diversity And Gene Flow In Fragmented Populations Of The Rare Shrub, Calothamnus Sp. Whicher, Sean Stankowski

Theses : Honours

Ca/othamnus sp. Whicher (Myrtaceae) is a narrow range endemic shrub restricted to ironstone soils near the town of Busselton in south-western Australia. Due to extensive land clearing for agriculture and mineral exploration, the species is fragmented over the majority of its range. In the present study, microsatellite markers were used to characterise levels of genetic diversity and describe levels of differentiation and gene flow among seven small, isolated road verge populations. Allelic diversity within the taxon over the six microsatellites was high (A = 17.6 ± 1.6). Diversity within populations was considerably lower (A = 5.19 ± 1.27), …

Pollen Characteristics Of Grevillea Species Determined By In Vitro Germination, Rebecca Parsons

Theses : Honours

Germination of pollen in vitro is a common technique used to assess the ability of pollen to germinate under a variety of conditions. The ability to determine the viability of a pollen grain, and optimal conditions for maximum germination and storage are important for hybridisation. A means of storing pollen, while maintaining viability, enables inter-species hybridisation between species that are spatially and temporally (flowering time) separated. The ultimate aim of hybridisation is seed set and in order to increase this in a genus renowned for a very low fruit to flower ratio, maximum pollen germination must be obtained. Therefore, by …

The Use Of Proline To Determine Salt Tolerance In Eucalyptus Species And Clones, Andrew J. Woodward

Theses: Doctorates and Masters

There have been a number of studies that have examined the Eucalyptus spp. for their salt and waterlogging tolerance: but they have done so using conventional methods. A wide range of plants are known to produce greater amounts of proline when stressed, be it salt, temperature, 'drought or several other types of stress. This study looked at production of proline in salt stressed eucalypts to determine whether it can be used to differentiate between individuals andspecies. A range of Eucalyptus species and salt tolerant clones of E. camaldulensis were grown to investigate their proline response to salt stress.

Banksia Woodland Resilience To Groundwater Drawdown On The Gnangara Mound, Llewellyn Broun

Theses : Honours

Water is considered to be the major limiting resource to plant growth and survival in regions with a Mediterranean-type climate, particularly during dry summer periods when low water potentials develop (Poole et al., 1981; Miller et al., 1983-84; Mooney and Miller, 1985; Stock et al., 1992). The Swan Coastal Plain is situated within this climatic region and interactions between the climate, soil and geology has an important bearing on the water requirements of the associated Banksia woodlands (Dodd and Heddle, 1989). The assessment of the condition of any vegetative community and in this case, the resilience of Banksia woodlands to …

The Effectiveness Of Post-Fire Weed Management And The Germination Ecology Of Selected Invasive Weed Species Of Bold Park, Brett Neasham

Theses : Honours

Bold Park is a 437 hectare A class reserve with high conservation value. Bold park is located on the Swan Coastal Plain, approximately 11 km west of the Perth CBD. Bold park is one of the few remaining coastal bushland reserves on the Swan Coastal Plain. High levels of floristic and faunal diversity contribute to Bold Park's conservation value. Weed invasion in Bold Park is reducing floristic diversity and is modifying ecosystem processes. Principle in the modified ecosystem processes is fire. While fire is a natural disturbance event in the bushland of the south-west of Western Australia, altered fire regimes …

Effects Of Temporary Par Reduction On The Seagrass Amphibolis Griffithii (Black) Den Hartog, Paul R. Mackey

Theses : Honours

Declines in seagrass health and distribution are commonly caused through human induced reductions in the availability of photosynthetically active radiation (PAR). These reductions can result from a variety of human-induced perturbations, including channel dredging. The impetus for the research was driven by the broad-scale degradation of the ecologically important southern-Australian endemic seagrass Amphibolis griffithii (Black) den Hartog in Champion Bay, Geraldton, Western Australia. The study investigated the affects of reduced PAR on A. griffithii and identified responses that may be useful in developing management triggers to minimise the impact of PAR limitation events. The study was carried out during late …

The Composition Of Cryptophytes (Geophytes) And Other Plants In The Northern Jarrah Forest Of Western Australia: An Analysis Of Logged And Old Growth Forest, Conrad C. Slee

Theses : Honours

Forests are decreasing globally and there are pressing requirements for ecologically sustainable forest management to be implemented at all scales. There has been some criticism of the public managers for forests and the processes used to select reserve systems and silvicultural methods used. Limited research has been conducted on the effects of logging on the plants of the northern Jarrah forest of south western Australia, While fire is a major disturbance event, disturbance during logging operations may remove non-commercial trees, understorey shrubs and change soil conditions. Some plants that regenerate from below ground storage organs such as Cryptophytes (Geophytes) may …

Patterns Of Water Uptake And Rhizosphere Salinity In Casuarina Obesa Miq. During A Drying Period At Lake Toolibin, Western Australia, Patrick J. Mitchell

Theses : Honours

Lake Toolibin is one of a few remaining freshwater lakes in the central wheatbelt of Western Australia. Since monitoring began at Lake Toolibin in the early 1970's groundwater levels have risen to within 1-2 m of the lakebed with an accompanying migration of salt. The site-specific nature of water uptake in Casuarina obesa Miq. (the dominant lakebed tree species) and rhizosphere salinity were explored spatially through analyses of soil properties (groundwater depth and salinity, particle size and components of soil water potential ψ₁). Plant water sources (using δ²H signatures) and water availability (based on ψ_{leaf …}

Variability In Water Use By Phreatophytic Banksia Woodland Vegetation Of The Swan Coastal Plain, Western Australia, Sandra Jane Zencich

Theses: Doctorates and Masters

Seasonal changes exist in source-water utilisation by Banksia woodland species overlying a shallow aquifer on the Swan Coastal Plain in Western Australia These were studied to identify the importance of groundwater as a water source to this vegetation. Intra-and interspecific variation in seasonal water use was investigated across the dominant overstorey and understorey species, with particular emphasis on species of different rooting morphologies. Seasonal water use was investigated across a topographical gradient ranging from a groundwater depth of 2.5 to 30 metres, a scenario representative of the coastal sand-dune system. An examination was also made of the response of woodland …

The Fringing Halophytic Vegetation Of Lake Austin: A Study Of Mining Impacts And Vegetation Dynamics, Simone Vellekoop

Theses : Honours

Mining operations in arid regions of Western Australia are faced with many environmental management issues. One such issue is the disposal of mine water to the environment. Mine water is commonly discharged to nearby salt lakes under licence by the Department of Environmental Protection. Licence conditions dictate that the discharge water and the receiving environment be monitored to allow impacts on the environment to be detected. Salt lakes are associated with vegetation communities dominated by halophytic members of the Chenopodiaceae, While these plants are tolerant of salinity extremes, the germination stage of many species requires periods of lowered salinity. There …

The Short Term Effects Of A Fire Fighting Foam And Fire Retardant On Selected Flora From Australia's Southwest, Andrew B. Kennedy

Theses : Honours

Chemical fire suppressants arc used extensively throughout Australia's Southwest to contain and suppress wildfires. Despite several studies being conducted into their effects on terrestrial vegetation in North America and Eastern Australia, where a variety of significant effects were found, no such investigation has been carried out in Australia's Southwest. This study examined the short-term effects of a fire fighting foam and fire retardant on selected flora from Australia's Southwest. Various concentrations of fire fighting foam and fire retardant were applied to seeds and seedlings of several native species. Native species were chosen for their high abundance and widespread distribution throughout …

Invasion Of Indigenous Vegetation In South-Western Australia By Leptospermum Laevigatum (Gaertn.) F. Muell. (Myrtaceae), Anya Lam

Theses : Honours

The current paradigm of biodiversity conservation requires the assessment of alien plant invaders, and their potential negative impacts on indigenous species and communities. Leptospermum laevigatum (Gaertn.) F. Muell. (Victorian tea tree/ Coast tea tree) is indigenous to eastern Australia. It has invaded ecosystems within its natural biogeographic range, within new ranges in Australia and overseas. The species is listed as a high priority weed in the Environmental Weed Strategy for Western Australia. However, the basis for its listing has been casual observation rather than focussed research. This study of L. laevigatum is unique in being the first to …

Salinity Tolerance Of Selected Ectomycorrhizal Fungi (Pisolithus Tinctorius Pers.) And Ectomycorrhizal Eucalypts, Ben Bradshaw

Theses : Honours

Increasing soil salinity has become a major problem worldwide. It has led to a reduction in the amount of arable land, has put at risk the supply of freshwater and threatens the existence of many natural habitats. The major increase in salinity has been attributed to human activities such as clearing of natural vegetation and large-scale irrigation programmes. The alleviation of this problem has focussed on changed management strategies. the most significant of which is the re-establishment of deep rooted plants in sail affected areas. This, however, is difficult because of the variation in salt tolerance of such plants and …

A Solid Phase Extraction System For The Isolation Of The Germination Cue In Smoky Water When Subjected To The Light Sensitive Lettuce Lactuca Sativa V. Grand Rapids, Troy David Adriansz

Theses : Honours

The search for the chemical or set of chemicals that act as a germination stimulant in Lactuca sativa v. Grand rapids (a variety of lettuce seed) was the underlying basis of this project. Through the development of a solid phase extraction (SPE) system different fractions of smoky water were tested for their effects on germination enhancement. The project targeted streamlining the amount of solvents as well as time used in past research on smoky water. Previously, several steps involving high perfo1mance liquid chromatography (HPLC), thin layer chromatography (TLC) and Gas Chromatography (GC) were employed. This project used SPE cartridges to …