ORCID Profile
0000-0003-2189-5870
Current Organisation
University of Tasmania
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Publisher: Wiley
Date: 23-11-2010
Publisher: Springer Science and Business Media LLC
Date: 12-2012
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/SB02037
Abstract: We identify the most widespread taxon of the Rubus fruticosus L. aggregate in Australia as a biotype of Rubus anglocandicans A. Newton, on the basis of morphological studies and analysis of M13/HaeIII DNA phenotypes using plant material collected from Australia, New Zealand, Europe and North America. Previous literature has confused this taxon with other Rubus taxa, especially R. procerus. We provide a full description and illustration of R. anglocandicans, including diagnostic characters separating it from R. armeniacus (R. procerus auct. mult.) and R. praecox. The morphology of R. anglocandicans in Australia differs slightly from specimens collected in England and it appears to exist as a clonal lineage, with 97% (n = 76) of s les characterised as DNA phenotype A. This taxonomic revision of this 'weed of national significance' will assist land managers in defining the weed problem prior to assessing management options that may vary in efficacy among species of the R.�fruticosus agg. Land managers have long assumed that Australia, New Zealand and north-western America share their most widespread biotype of the R. fruticosus agg. namely, the taxon now known as R. armeniacus. R.�armeniacus, DNA phenotype B, was found in Germany, New Zealand and north-western America, but has not been identified in Australia to date.
Publisher: Springer Science and Business Media LLC
Date: 13-10-2013
Publisher: Oxford University Press (OUP)
Date: 08-2200
DOI: 10.1111/JAM.13530
Abstract: To investigate selected factors of two nonaerated compost teas (NCT) and mechanisms that influence the restriction of several fungal potato pathogens. Two NCTs, made from either commercial compost, (CCT) or vineyard compost (VCT), were tested for their ability to suppress potato pathogens. The VCT was more suppressive than CCT to mycelial growth of Alternaria solani and Rhizoctonia solani isolate 299, but not for R. solani isolate 422. Metagenomic studies of microbial ersity revealed that the CCT had higher fungal and bacterial ersity and richness than the VCT. Use of CCT significantly reduced lesion area of Alternaria alternata on detached leaves, however, a gum adjuvant did not lead to significantly greater control. Scanning microscopy showed that the spatial distribution of microbes from the CCT was altered with gum addition, to resemble what may have been a microbial biofilm. We confirmed that each NCT could suppress the mycelial growth of selected potato pathogens in culture, and CCT reduced A. alternata lesions on detached leaves. Factors including concentration, microbial communities and physio-chemical properties could not be consistently linked to NCT efficacy. This study particularly highlights the application of scanning microscopy to study the interaction between pathogens and putative NCT microbes on foliar surfaces. This adds insight to mechanisms of NCT efficacy, along with physico-chemical and microbial characterization of the teas. This study shows the potential for the use of NCTs as a crop protection tool of low-cost which could be of particular benefit in smallholder agriculture.
Publisher: MDPI AG
Date: 18-09-2018
DOI: 10.3390/F9090577
Abstract: Harvest residues can play a crucial role in conserving nutrients for recycling in forests, but little is known about the rates of decomposition and nutrient release from these residues following logging in tropical acacia plantations. In this study, we examined the biomass and nutrient content of harvest residue components (bark, leaves, and branches) using the litterbag technique for a 1.5-year-period following harvest of a seven-year-old Acacia mangium plantation in Northern Vietnam. At harvest, the total dry biomass of harvest residues was 18 t ha−1 comprising bark (8.9 t ha−1), branches (6.6 t ha−1), and leaves (2.5 t ha−1). The retained bark on site conserved 51% N, 29% P, 32% K, 64% Ca, and 24% Mg content from harvest residues for recycling. Decomposition rate of the leaves was the most rapid (k = 1.47 year−1 t0.5 = 0.47 year), then branches (k = 0.54 year−1 t0.5 = 1.29 year), and bark (k = 0.22 year−1 t0.5 = 3.09 year). During decomposition, the loss of nutrients from harvest residues was K ≈ Ca N P Mg. Decomposition of harvest residues and the associated rate of nutrient release can potentially supply a significant amount of nutrients required for stand development in the next rotation.
Publisher: Wiley
Date: 26-09-2006
Publisher: American Society for Microbiology
Date: 09-2008
DOI: 10.1128/AEM.02885-07
Abstract: Phragmidium violaceum causes leaf rust on the European blackberry ( Rubus fruticosus L. aggregate). Multiple strains of this pathogen have been introduced into southern Australia for the biological control of at least 15 taxa of European blackberry, a nonindigenous, invasive plant. In climates conducive to leaf rust, the intensity of disease varies within and among infestations of the genetically variable host. Genetic markers developed from the selective lification of microsatellite polymorphic loci were used to assess the population genetic structure and reproductive biology of P. violaceum within and among four geographically isolated and diseased infestations of the European blackberry in Victoria, Australia. Despite the potential for long-distance aerial dispersal of urediniospores, there was significant genetic differentiation among all populations, which was not associated with geographic separation. An assessment of multilocus linkage disequilibrium revealed temporal and geographic variation in the occurrence of random mating among the four populations. The presence of sexual spore states and the results of genetic analyses indicated that recombination, and potentially random migration and genetic drift, played an important role in maintaining genotypic variation within populations. Recombination and genetic differentiation in P. violaceum , as well as the potential for metapopulation structure, suggest the need to release additional, genetically erse strains of the biocontrol agent at numerous sites across the distribution of the Australian blackberry infestation for maximum establishment and persistence.
Publisher: Springer Science and Business Media LLC
Date: 25-02-2022
DOI: 10.1007/S10658-022-02479-W
Abstract: Ceratocystis wilt and canker disease has devastated Acacia mangium plantations in south-east Asia. Current screening methodologies to identify resistant or tolerant germplasm use potted plants in a greenhouse as a preliminary screening to select material for field trials, but these tests are time-consuming, motivating a search for rapid screening protocols. In this study, inoculation procedures were tested on three species of Acacia , viz. A. mangium , A. crassicarpa and a hybrid of A. auriculiformis and A. mangium , using three isolates of Ceratocystis manginecans . Mycelial plugs were compared with spore suspensions as inoculum to infect artificial wounds on the stems of A. mangium potted plants. The rapid screening protocols involved inoculation of stem segments with mycelial plugs and detached phyllodes with a spore suspension, with susceptibility measured by lesion length on the stems or necrosis length on the phyllodes. Both mycelial plugs and spore suspensions produced a similar level of disease incidence, so either inoculum form can be used for an assay. The stem segments were prone to contamination by other fungi and to desiccation, while results from the potted plant and phyllode protocols showed similar trends of susceptibility among the Acacia clones and species. The ease, rapidity, and reproducibility of the phyllode inoculation protocol makes it a potential replacement for inoculation of potted plants as a preliminary screening protocol to identify disease tolerant A. mangium germplasm prior to field screening.
Publisher: Scientific Societies
Date: 1993
DOI: 10.1094/PHYTO-82-890
Publisher: Springer Science and Business Media LLC
Date: 2000
DOI: 10.1071/AP00047
Publisher: Hindawi Limited
Date: 29-06-2011
Publisher: Informa UK Limited
Date: 04-03-2017
Publisher: Springer Science and Business Media LLC
Date: 17-02-2013
Publisher: Hindawi Limited
Date: 22-09-2014
DOI: 10.1111/AJGW.12101
Publisher: Elsevier BV
Date: 08-1997
Publisher: Springer Science and Business Media LLC
Date: 2003
DOI: 10.1071/AP03012
Publisher: Springer Science and Business Media LLC
Date: 21-10-2022
Publisher: Springer International Publishing
Date: 2014
Publisher: International Society for Horticultural Science (ISHS)
Date: 02-2016
Publisher: Hindawi Limited
Date: 21-01-2019
DOI: 10.1111/AJGW.12381
Publisher: Elsevier BV
Date: 04-2006
DOI: 10.1016/J.MYCRES.2005.11.014
Abstract: Indigenous to Europe, the blackberry rust fungus Phragmidium violaceum was introduced to Australia and subsequently appeared in New Zealand, with the most recent authorised introductions to Australia specifically for the biological control of European blackberry. Markers for 'selective lification of microsatellite polymorphic loci' (SAMPL) were developed for studying the population genetics of P. violaceum. Modification of one of the two SAMPL primers with a HaeIII adapter (H) revealed significantly greater levels of genetic variation than primers used to generate AFLPs, the latter revealing little or no variation among 25 Australasian and 19 European isolates of P. violaceum. SAMPL was used to describe genetic variation among these 44 isolates of P. violaceum from 51 loci generated using primer pairs (GACA)4 +H-G and R1+H-G. The European isolates were more erse than Australasian isolates, with 37 and 22 % polymorphic loci, respectively. Cluster analysis revealed geographic clades, with Australasian isolates forming one cluster separated from two clusters comprising the European isolates. However, low bootstrap support at these clades suggested that Australian isolates had not differentiated significantly from European isolates since the first record of P. violaceum in Australia in 1984. In general, the results support two hypotheses. First, that the population of P. violaceum in Australia was founded from a subset of in iduals originating from Europe. Second, that P. violaceum in New Zealand originated from the Australian population of P. violaceum, probably by wind dispersal of urediniospores across the Tasman Sea. The application of SAMPL markers to the current biological control programme for European blackberry is discussed.
Publisher: Springer Science and Business Media LLC
Date: 26-05-2011
Publisher: Wiley
Date: 26-09-2006
Publisher: National Inquiry Services Center (NISC)
Date: 14-03-2019
Publisher: National Inquiry Services Center (NISC)
Date: 02-04-2020
Publisher: Wiley
Date: 06-2005
Publisher: Wiley
Date: 06-04-2010
DOI: 10.1111/J.1755-0998.2010.02851.X
Abstract: This article documents the addition of 220 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Allanblackia floribunda, Amblyraja radiata, Bactrocera cucurbitae, Brachycaudus helichrysi, Calopogonium mucunoides, Dissodactylus primitivus, Elodea canadensis, Ephydatia fluviatilis, Galapaganus howdenae howdenae, Hoplostethus atlanticus, Ischnura elegans, Larimichthys polyactis, Opheodrys vernalis, Pelteobagrus fulvidraco, Phragmidium violaceum, Pistacia vera, and Thunnus thynnus. These loci were cross-tested on the following species: Allanblackia gabonensis, Allanblackia stanerana, Neoceratitis cyanescens, Dacus ciliatus, Dacus demmerezi, Bactrocera zonata, Ceratitis capitata, Ceratitis rosa, Ceratits catoirii, Dacus punctatifrons, Ephydatia mülleri, Spongilla lacustris, Geodia cydonium, Axinella sp., Ischnura graellsii, Ischnura ramburii, Ischnura pumilio, Pistacia integerrima and Pistacia terebinthus.
Publisher: Hindawi Limited
Date: 06-10-2022
DOI: 10.1111/AJGW.12525
Publisher: Elsevier BV
Date: 06-1996
Publisher: Informa UK Limited
Date: 06-2010
Publisher: Scientific Societies
Date: 12-2020
DOI: 10.1094/PDIS-04-20-0812-FE
Abstract: The incursion of a plant pathogen into a new geographic area initiates a series of decisions about appropriate control or eradication efforts. Incomplete, erroneous, and/or selective information may be used by erse stakeholders to support in idual goals and positions on how an incursion should be managed. We discuss the complex social, political, and technical factors that shape a biosecurity response prior to reviewing information needs and common stakeholder misunderstandings. Selected ex les focus on the rust fungi (order Pucciniales). We then explore how plant pathologists, as technical experts, can interact with biosecurity stakeholders to build empathy and understanding that in turn allows a shift from being a distant subject matter expert to an active participant helping to structure problems and shape knowledge flows for better outcomes.
Publisher: Springer Science and Business Media LLC
Date: 1997
DOI: 10.1071/AP97002
Publisher: Hindawi Limited
Date: 20-01-2012
DOI: 10.1111/AJGW.12011
Publisher: Scientific Societies
Date: 12-2018
DOI: 10.1094/PHYTO-03-18-0098-R
Abstract: Sour rot, a disease affecting berries of cultivated Vitis spp. worldwide, has not been clearly defined. Reported symptoms of the disease include browning of the berry skin, oozing of disintegrated berry pulp, and the smell of acetic acid, all in the presence of fruit flies (Drosophila spp.). We determined acetic acid concentrations in multiple collections of symptomatic berries, isolated and identified microbes from them, and inoculated commonly isolated organisms into healthy berries with and without concurrent exposure to wild-type or axenic Drosophila melanogaster. Coinoculations combining one of several yeasts (Metschnikowia spp., Pichia spp., and a Saccharomyces sp.) plus an acetic acid bacterium (an Acetobacter sp. and Gluconobacter spp.) reproduced sour rot symptoms, defined here as decaying berries with a loss of turgor and containing acetic acid at a minimum of 0.83 g/liter, based on observed field levels. Symptoms developed only in the presence of D. melanogaster, either wild type or axenic, indicating a nonmicrobial contribution of these insects in addition to a previously suggested microbial role. We conclude that sour rot is the culmination of coinfection by various yeasts, which convert grape sugars to ethanol, and bacteria that oxidize the ethanol to acetic acid, and that this process is mediated by Drosophila spp.
Publisher: Wiley
Date: 26-05-2014
DOI: 10.1111/PPA.12225
Publisher: Scientific Societies
Date: 2019
DOI: 10.1094/PHYTO-10-17-0357-R
Abstract: Botrytis bunch rot (BBR), caused by Botrytis cinerea, results in serious losses to wine-grape production in some seasons during the preharvest period. In order to predict seasons that are at risk from BBR, datasets consisting of 25 disease, weather and vine phenology variables were aggregated from 101 SiteYears across seven regions and nine growing seasons. Automated analyses were used to compare a range of statistical methods for their ability to predict BBR epidemics, including the Kruskal-Wallis test, logistic regression, receiver operating characteristic analysis, and skill-scores. Variables based on relative humidity and surface-wetness duration were significant and consistent predictors of BBR epidemics across the range of analyses applied. Variables integrating temperature and wetness duration, including the Bacchus and Broome models, also demonstrated high predictive ability however, they did not outperform their constituent components in all analyses. Automation of data analyses was an effective way to compare a wide range of statistical methods and a large number of variables with minimal user input, following initial code development. Significant time was needed to check input data and software code, but a greater return on investment would occur should the analytical process be applied to new datasets, including those from other pathosystems.
Publisher: Scientific Societies
Date: 1994
DOI: 10.1094/PD-78-0979
Publisher: Oxford University Press (OUP)
Date: 09-07-2010
DOI: 10.1111/J.1365-2672.2010.04794.X
Abstract: The aim was to produce and characterize an aerated compost tea (ACT) that suppressed growth of the plant pathogen Botrytis cinerea. Three different open-windrow composts were s led weekly from the early secondary mesophilic stage until maturity. Each 10kg of compost s le was extracted in 30 l of aerated water for 24, 48 or 72h. Relative to water, all batches of ACT applied to detached bean leaflets reduced lesion development following single-point inoculations of B. cinerea. There was a significant linear, inverse relationship between the internal windrow temperature of compost (≤51°C) used to prepare ACT and the extent of lesion development. Bacterial ersity in ACTs from one windrow was highest using compost s led at 48°C. The compost weight-to-water volume ratios of 1:3, 1:10 or 1:30, using compost s led from a fourth windrow at 50°C, also produced ACTs that reduced the growth of B. cinerea on bean leaflets. The '1 : 3' ACT, and to a lesser degree the same ACT filtered to remove micro-organisms, inhibited the germination of B. cinerea conidia. ACT produced using the methods reported here suppressed the growth of B. cinerea on bean leaflets, with an abundant and erse microbial community likely to contribute to pathogen suppression. This is the first report of the use of immature compost to produce a pathogen-suppressive ACT, suggesting that compost stage is an important production variable.
Publisher: Springer Science and Business Media LLC
Date: 14-09-2022
DOI: 10.1007/S13593-022-00829-W
Abstract: Grape growers are often constrained by available time and labor to conduct trials that deliver informative results. Spatially distributed trial designs coupled with data collection using sensing technologies can introduce efficiencies and also account for the impact of land variability on trial results. Various spatial approaches have been proposed, yet how farmers perceive them is largely unknown. We collaborated with four wine businesses in Australia to explore how grape growers and viticultural consultants perceive a simplified spatial approach to experimentation involving one or more vineyard rows or “strips.” In each case, the simplified strip approach was applied alongside growers’ or consultants’ own methods to compare the perceived value of different methods. The Theory of Planned Behavior was used as an analytical framework to identify factors influencing participants’ intentions towards adopting the strip approach. Our findings show that growers and consultants perceived several advantages of the strip approach over their own methods. Key factors impeding uptake were resource constraints for collecting trial data and lack of skills and knowledge to use and analyze spatial data to position the trial and interpret results. These constraints highlight the need to support growers and consultants who see value in this approach by developing automated and affordable measurements for viticultural variables beyond yield, and by providing training on how to analyze and interpret spatial and response data. This study provides novel insights for private and public sectors on where to focus efforts to facilitate adoption of spatial approaches to On-Farm Experimentation by specific target audiences.
Publisher: SAGE Publications
Date: 2013
DOI: 10.1255/JNIRS.1083
Abstract: Botrytis bunch rot (BBR), one of the most important diseases of wine grapes, is usually quantified in the vineyard by visual estimation of percentage disease severity on in idual grape bunches. This method is prone to assessor error and there is a need for a more objective quantification method that is cost-effective and practical. Near infrared (NIR 800–2690 nm) and mid-infrared (mid-IR 2510–25, 770 nm) spectroscopy were investigated as alternatives to visual estimation. Partial least squares (PLS) analysis of the NIR and mid-IR spectra from near-ripe grape bunches from Tasmanian vineyards was used to generate prediction models from both raw data and data pre-processed using the Savitzky–Golay derivative. The entire spectral range for each spectral region was analysed first, after which specific spectral ranges were analysed based on their influence on the initial PLS analysis. The spectral range of 1260–1370 nm with Savitzky–Golay smoothing and first derivative pre-processing produced the PLS model with the highest predictive ability in the NIR spectral region, with a ratio of standard error of prediction to standard deviation ( RPD) of 2.2. The spectral range of 8760–9520 nm with Savitzky–Golay smoothing and first derivative pre-processing produced the PLS model with the highest predictive ability in the mid-IR spectral region, with a RPD of 1.7. Both methods demonstrated the potential for spectroscopic quantification of BBR. However, further calibration is required to increase the accuracy of these models, particularly at low BBR severities, if they are to be considered suitable for use in the vineyard.
Publisher: Universite de Bordeaux
Date: 18-01-2023
DOI: 10.20870/OENO-ONE.2023.57.1.5542
Abstract: The main difficulties grapegrowers and consultants face in obtaining robust trial results include time and labour to collect data and land variability that confounds trial results. Spatial approaches that use whole-field designs, sensing technologies and geostatistical analysis enable more efficient data collection and account for the impact of spatial variation on crop responses while generating statistically robust results. However, the practical application of these approaches for vineyard trials requires affordable automation of measurements of viticultural variables and access to skills for geostatistics. A strip approach has been developed to simplify experimentation by allowing the farmer to use a single crop row to trial and analyse data in a spreadsheet. However, guidance is needed as to how to position trial strips in a vineyard block to reveal likely treatment effects across the entire block. Here, we investigated using a covariate to a response variable of interest to position a strip trial to infer treatment effects beyond the trial strip. Strip trials were simulated for two experiments: one comparing three treatments for vineyard floor management on grape yield and another comparing two spray programs for powdery mildew control. Useful covariates for yield or mildew severity were determined using correlation analyses. Trial results were analysed using a moving pairwise comparison of treatments and a moving average of the covariates. Simulated trial strips that incorporated a range of variation in a useful covariate close to that encountered in the whole block showed how yield or mildew severity varied with the covariates along the strips. Importantly, such results provided information about likely crop responses in other parts of the block according to variation in the covariates, thus contributing to better-informed decision-making. Compared to whole-field approaches, this strip approach is more efficient and simpler for growers to implement.
Start Date: 2014
End Date: 2014
Funder: Australian Grape and Wine Authority
View Funded ActivityStart Date: 2008
End Date: 2010
Funder: Department of Industry and Science
View Funded ActivityStart Date: 2015
End Date: 2016
Funder: University of Tasmania
View Funded Activity