ORCID Profile
0000-0002-5571-9114
Current Organisation
University of Queensland
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Publisher: MDPI AG
Date: 19-10-2021
Abstract: While there are many high profile Opuntioid cactus species invading rangeland environments in Australia, Cereus uruguayanus Ritt. ex Kiesl. has also naturalised and formed large and dense infestations at several locations. With no herbicides registered for control of C. uruguayanus in Australia, the primary aim of this study was to identify effective herbicides to control it using a range of techniques. This involved a large screening trial of twelve herbicides and four techniques, followed by a rate refinement trial for cut stump applications and another to test residual herbicides. Despite most treatments (except monosodium methylarsonate (MSMA)) taking a long time to kill plants, at least one effective herbicide was identified for basal bark (triclopyr icloram), cut stump (aminopyralid/metsulfuron-methyl, glyphosate, metsulfuron-methyl, triclopyr icloram, triclopyr icloram/aminopyralid), stem injection (glyphosate, MSMA, triclopyr icloram/aminopyralid) and foliar applications (aminopyralid/metsulfuron-methyl, MSMA, triclopyr, triclopyr icloram/aminopyralid) due to their ability to kill both small and large plants. Ground application of residual herbicides was less conclusive with neither hexazinone nor tebuthiuron causing adequate mortality at the rates applied. This study has identified effective herbicides for the control of C. uruguayanus using several techniques, but further research is needed to refine herbicide rates and develop integrated management strategies for a range of situations and infestation sizes and densities.
Publisher: CSIRO Publishing
Date: 19-12-2022
DOI: 10.1071/RJ22022
Abstract: Cereus uruguayanus R.Kiesling is a naturalised, non-opuntioid cactus that has formed large and dense infestations at several locations in the northern Australian rangelands. Of the Cactoideae subfamily, it typically grows into a large, spiny, single- or multi-stemmed candelabra-shaped cactus. While not classified as a Weed of National Significance (WONS) in Australia, it is causing increasing concern, with some local governments declaring it under their local laws. Recent research has identified several herbicides that control C. uruguayanus by using a range of techniques, including basal-bark, cut-stump, foliar, and stem injection applications. Of these, stem injection is one of the recommended options where weeds grow among desirable vegetation because the risk of non-target damage is minimised. This study evaluated C. uruguayanus control using a range of encapsulated dry-formulation herbicides from BioHerbicides Australia (BHA Pty Ltd), using their novel stem-implantation system (Injecta®). In May 2018, an experiment was established in central Queensland to compare the efficacy of six encapsulated herbicides (aminopyralid + metsulfuron-methyl, clopyralid, glyphosate, hexazinone, metsulfuron-methyl, triclopyr + picloram) against an untreated control. Glyphosate was the fastest-acting herbicide, followed by aminopyralid + metsulfuron-methyl and metsulfuron-methyl, with triclopyr + picloram much slower to act. Nevertheless, all four herbicides eventually caused high mortality (≥85%). In contrast, clopyralid and hexazinone were ineffective at the applied rates. Future research is recommended to compare the cost effectiveness of this system against other techniques, particularly those used for stem-injection applications.
Publisher: MDPI AG
Date: 14-05-2022
DOI: 10.3390/ANI12101267
Abstract: The frequent monitoring of a horse’s body temperature post strenuous exercise is critical to prevent or alleviate exertional heat illness (EHI) from occurring. Percutaneous thermal sensing microchip (PTSM) technology has the potential to be used as a means of monitoring a horse’s body temperature during and post-exercise. However, the accuracy of the temperature readings obtained, and their relationship to core body temperature are dependent on where they are implanted. This study aimed to document the relationship between core body temperature, and temperature readings obtained using PTSM implanted in different muscles, during exercise and post application of different cool-down methods. PTSMs were implanted into the right pectoral, right gluteal, right splenius muscles, and nuchal ligament. The temperatures were monitored during treadmill exercise, and post application of three different cool-down methods: no water application (Wno), water application only (Wonly), and water application following scraping (Wscraping). Central venous temperature (TCV) and PTSM temperatures from each region were obtained to investigate the optimal body site for microchip implantation. In this study, PTSM technology provided a practical, safe, and quick means of measuring body temperature in horses. However, its temperature readings varied depending on the implantation site. All muscle temperature readings exhibited strong relationships with TCV (r = 0.85~0.92, p 0.05) after treadmill exercise without human intervention (water application), while the nuchal ligament temperature showed poor relationship with TCV. The relationships between TCV and PTSM temperatures became weaker with water application. Overall, however the pectoral muscle temperature measured by PTSM technology had the most constant relationships with TCV and showed the best potential to act as an alternate means of monitoring body temperature in horses for 50 min post-exercise, when there was no human intervention with cold water application.
Publisher: MDPI AG
Date: 06-02-2022
Abstract: Chinese elm [Celtis sinensis Pers.] is an emerging environmental weed naturalised throughout the coastal and riparian (creek-banks, river margins, and streams) regions of eastern Australia. Throughout this introduced range, its management is limited to the application of synthetic herbicides and mechanical clearing operations (terrain and soil type permitting). The current mechanisms of chemical control (basal bark spraying, stem-injection, and cut-stump applications) often result in collateral damage to non-target native species (such as Eucalyptus spp. and Casuarina cunninghamiana Miq.) through herbicidal drift, runoff or leaching into adjacent habitats. This has raised concerns regarding the suitability of synthetic herbicides in ecologically sensitive (e.g., riparian zones, rainforest margins, and woodlands) or low-value habitats, thereby promoting significant developments in the fields of integrated weed management. This study investigated the effectiveness of a novel stem-implantation system for controlling woody weed species in the context of a conserved habitat. A replicated trial (n = 315) was established among a naturally occurring population of C. sinensis. This trial involved the mapping, measurement, and treatment of this invasive species with five encapsulated synthetic herbicides, as well as an untreated control and benchmark treatment (diesel + AccessTM). A significant effect (p 0.05) on plant vigour and functional canopy was discerned for each assessment period following trial establishment. The highest incidence of mortality was observed among the in iduals treated with glyphosate (245 mg/capsule), aminopyralid and metsulfuron-methyl (58.1 and 37.5 mg/capsule) and picloram (10 mg/capsule), achieving a similar response to the basal bark application of diesel and AccessTM (240 g/L triclopyr, 120 g/L picloram, and 389 g/L liquid hydrocarbon). This was also evidenced by a rapid reduction in functional canopy (i.e., no or little living leaf tissue) from three weeks after treatment. Unlike their industry counterparts, these encapsulated herbicides are immediately sealed into the vascular system of the target species by a plug. This significantly minimises the possibility of environmental or operator exposure to synthetic compounds by providing a targeted, readily calibrated herbicide application.
Publisher: CSIRO Publishing
Date: 09-03-2023
DOI: 10.1071/RJ22019
Abstract: Biocrusts form a living soil cover in Australia’s northern savannas, delivering essential ecosystem services. More accessible tools are needed to quantify and monitor ground cover, including biocrusts, as current methodologies are time-consuming, expensive, or specialised. At Victoria River Research Station (Northern Territory, Australia), long-term fire research plots were used to monitor the response of low vegetative ground and soil covers for different burning intervals and seasons. Mobile phone photographs were analysed using machine-learning software and a derived decision tree-based segmentation model (DTSM). The resulting data were compared to visual in-field assessment by trained researchers. Visual assessments and photographs were taken at two time points during the post-fire recovery period, mid-wet and dry seasons, at three burning intervals (2, 4, and 6 years) and for two different burning times, early or late dry season. DTSM-derived grass and litter cover were statistically similar to field observations in the burnt and unburnt plots. Biocrust cover derived from DTSM also matched field observations in fire treatments and unburnt control plots in the dry season, except when obscured by grass or litter. In the wet season, DTSM underestimated biocrust cover in some treatments, and DTSM did not detect biocrust obscured under dense grass cover. Nevertheless, biocrust pigment analysis confirmed a significant presence of biocrusts both on seemingly bare soil and under the grass canopy. We concluded that mobile phone photographs are suitable for monitoring dry-season ground cover. When similar colours of grass and litter cover were combined, the modelled accuracy reached 95–97%. With some refinements, DTSM analysis of photographs could accurately quantify the impact of fire disturbance on biocrusts and grass cover. However, it would be advantageous to improve the model by additional field records to determine how much biocrust occurs under the grass. This study provides land managers with an efficient method of recording ground cover over time to aid land-condition assessments.
Publisher: Elsevier BV
Date: 08-2022
Publisher: Elsevier BV
Date: 09-2021
Publisher: Cambridge University Press (CUP)
Date: 2021
DOI: 10.1017/EXP.2021.31
Abstract: In this study, we define the cardinal temperatures and thermal time for germination and emergence of pigeonpea genotypes. Seeds of six genotypes were subjected to constant temperatures ranging between 5 and 50°C in petri dishes with filter paper (germination) and with media (emergence) were placed in a thermal gradient plate. A nonlinear bent-stick model fitted to the rate of development to germination and emergence resulted in parameters predicting cardinal temperatures including base ( T b ), optimum ( T o ), maximum ( T m ), and thermal time. Estimated T b for 50% germination and emergence were 8.4 and 10.8°C, respectively, with no significant differences between genotypes. Optimum temperatures were 33.8 and 37.9°C for germination and emergence, respectively, with genotypes differing significantly. Thermal time for 50% germination and emergence varied significantly among genotypes. The results suggest that genotypic responses to the temperature are typical for their tropical origin and hence their suitability for cropping in summer dominant rainfall regions insubtropical Australia.
Publisher: Elsevier BV
Date: 10-2022
Publisher: American Chemical Society (ACS)
Date: 09-03-2022
Publisher: World Scientific Pub Co Pte Lt
Date: 08-2018
DOI: 10.1142/S0129183118500638
Abstract: This paper reviews the work of Wu and Lin on the Union Jack lattice Ising model. This model is of interest as it one of the few to display re-entrant phase transitions. Specifically, we re-examine their result for the general anisotropic sublattice magnetizations, comparing these with the works of Vaks, Larkin and Ovchinnikov, and our own numerical simulations. We discuss the disagreements found in both sublattice predictions including non-zero antiferromagnetic results and a rotational variance. We will then suggest additional conditions and modified formulae that will allow valid results to be produced.
Publisher: Elsevier BV
Date: 09-2022
DOI: 10.1016/J.ANIMAL.2022.100620
Abstract: Continuous accurate attainment of the body temperature of foals is important to detect early stages of severe heat stress or fever due to a systemic illness. Among a number of methods to measure body temperature, measuring rectal temperature with a digital thermometer is most frequently used due to being relatively fast and simple method. It is also comparatively accurate and correlates well with the core body temperature. However, this method requires restraining the foal for a few seconds to obtain the temperature, and it can be dangerous for the handling person. Percutaneous thermal sensing microchips (PTSMs) are a means of monitoring the body temperature of horses, which offers a non-invasive, hygienic, quick, and accurate way to measure body temperature and provide an identification number for each in idual, once it is implanted. This study tested the hypothesis that PTSM has a strong relationship with a conventional body temperature measurement, i.e., measuring rectal temperature with a digital thermometer of foals during summer seasons. Thirty-two foals in three consecutive foaling seasons (2018, 2019, and 2020 season) were implanted a PTSM into the right pectoral muscle, the right splenius muscle, the right gluteal muscle, and the nuchal ligament as early as two weeks after birth. The four PTSM temperatures, rectal temperature, and climate conditions (air temperature, relative humidity, and wet-bulb globe temperature) were obtained simultaneously during the three summer seasons and paired for comparison analysis. Among the PTSM temperatures, the pectoral muscle had the highest correlation and the least differences with rectal temperature. Using PTSM was safe, easy, and reliable for attaining body temperature in foals.
Publisher: CSIRO Publishing
Date: 10-06-2022
DOI: 10.1071/CP21209
Abstract: Context Mungbean (Vigna radiata (L.) Wilczek) is an important grain legume for food, feed, and green manure. Mungbean yield is highly variable due to fluctuating temperature and unpredictable rainfall. Aims To improve yield stability, it is critical to utilise a model that can simulate mungbean phenology, biomass, and yield accurately. Methods A thorough understanding of the physiological determinants of growth and yield is required to advance existing mungbean crop modelling capability. Currently, there is limited understanding of the physiological determinants of canopy and reproductive development and their variation in mungbean germplasm. Two experiments (controlled and field environments) were conducted at Gatton, Queensland, in 2018–19. Six Australian mungbean genotypes and one black gram (Vigna mungo L.) were grown under non-limiting conditions. Plant phenotypic traits (canopy development, time to first, 50% flowering, duration of flowering and podding, flower appearance, pod addition rates) were recorded. Key results Genotypes M10403 and Satin II had significantly higher leaf appearance rate (LAR). Genotypes with a greater LAR had higher number of leaves but lower in idual leaf area. Genotypes varied significantly in time to first and 50% flowering, with Onyx-AU (black gram) and Celera II-AU flowering earliest. Flowering and podding rates, and duration of these phenological phases varied among genotypes. Total plant leaf area (TPLA) approached its maximum at mid-podding stage. Implications This study quantified the key phenotypic and physiological relationships associated with canopy and reproductive development, critical for the improvement of mungbean crop modelling required to accurately simulate growth and development and inform possible canopy constraints that are limiting mungbean productivity.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Vincent Mellor.