Antibiotic Sensitivity Testing

Respiratory bacterial pathogens in pigs are currently treated with antibiotics. Intervet - Schering Plough markets an antibiotic called Nurflor (Florfenicol) targeting respiratory pathogens. This project tests the effectiveness of this antibiotic against a series of respiratory pathogens. 6 isolates will be tested per serovar/strain and the isolates will be from 4 different farms using MIC testing. The sensitivity of Florfenicol will be compared to sensitivity of the organisms to Tilmicosin and Amoxicillin. Development of resistance to certain antibiotics have been reported, so it is important to have alternative antibiotics available to treat the respiratory pathogens on farms.

Extension of Chemical Phytotoxicity Testing Facility for Warm-Season Turfgrasses

The turf industry needs to access a range of more selective, effective and environmentally acceptable pesticides, which will help to address environmental concerns while maintaining the industry's internationally competitive status. This includes both new pesticides being developed globally for turf use and older generic chemicals previously registered for other agricultural purposes and now requiring extension of that registration for use in turf.

Fruit fly host status testing of a new passionfruit cultivar

Fruit fly host status testing of a new passionfruit cultivar.

Testing Postharvest Mango treatments

The effectiveness of Amistar and ASM combinations, in reducing the severity of postharvest anthracnose and stem end rot in mango.

Soil Micro Testing

Soil Micro Testing for nematodes on grain farms.

Sorghum Midge Testing Scheme

Scheme provides independant testing and official industry midge resistance rating of pre-commercial sorghum varieities.

Testing the efficacy of low volume herbicide applications on Chromolaena odorata

Siam Weed (Chromoleana odorata) is the target of an eradication program in north Queensland; however some infestations occur on ground inaccessible to high volume, ground based herbicide spray equipment. Four foliar herbicides were applied to dense infestations of mature Siam Weed in March 2009, near Townsville, north Queensland. Low volume, high concentration solutions containing 40 g L-1 a.i. glyphosate, 1.2 g L-1 a.i metsulfuron-methyl, 10 g L-1 a.i. fluroxypyr + 0.7 g L-1 a.i. aminopyralid and 15 g L-1 a.i. triclopyr + 5 g L-1 a.i. picloram + 0.4 g L-1 a.i. aminopyralid were applied using a 5 L backpack and hand gun (or splatter gun). Relatively small amounts (approximately 24-28 mL) of the high concentration solutions were applied to each bush and assessments of the replicated treated and untreated control plots were conducted 76, 207 and 356 days after treatment. These assessments demonstrated that the fluroxypyr and triclopyr based herbicides controlled 96 to 100% of plants. The metsulfuron-methyl and glyphosate based herbicides controlled 40 and 57% of plants respectively 12 months after treatment, when 3% of untreated control plants were dead. The trial demonstrated that this application method and either of two herbicides provides an additional tool for controlling Siam weed in remote areas, which are inaccessible to traditional higher volume foliar herbicide applications. Lower volume herbicide solutions reduce the volume of water and thus the effort needed to effectively treat less accessible infestations.

Biodegradation of 1080: Testing soils in south-eastern Australia for sodium fluoroacetate-degrading micro-organisms

Sodium fluoroacetate (1080) is a vertebrate poison commonly used for the control of vertebrate pests in Australia. Long-term environmental persistence of 1080 from baiting operations has likely nontarget species and environmental impacts and is a matter of public concern. Defluorinating micro-organisms have been detected in soils of Western and central Australia, and Queensland, but not in south-eastern Australia. The presence or absence of defluorinating micro-organisms in soils from south-eastern Australia will assist in determining whether long-term environmental persistence of 1080 is or is not occurring. Soils from the Central West Slopes and Plains and Central Tablelands of New South Wales were sampled to investigate the presence and capability of 1080 defluorinating soil micro-organisms. Thirty-one species of micro-organisms were isolated from soils from each site after 10 days incubation in a 20 mM 1080 solution. Of these, 13 isolates showed measurable defluorinating ability when grown in a 1080 and sterile soil suspension. Two species, the bacteria Micromonospora, and the actinomycete Streptosporangium, have not been previously reported for their defluorinating ability. These results indicate that defluorinating micro-organisms are present in soils in south-eastern Australia, which adds weight to other studies that found that 1080 is subject to microbiological degradative processes following removal from the bait substrate. Soil micro-organism defluorination, in combination with physical breakdown and uptake by plants, indicates that fluoroacetate in soils and natural water ways is unlikely to persist. This has implications for the better informed use of 1080 in pest animal management programmes in south-eastern Australia.

Structural Veneer Based Composite Products from Hardwood Thinning - Part II: Testing of Hollow Utility Poles

Australian utility pole network is aging and reaching its end of life, with 70% of the 5 million poles currently in-service nationally installed within the 20 years following the end of World War II. The estimated investment required for the replacement or remedial maintenance of the aging 3.5 millions poles is as high as 1.75 billion dollars. Additionally, an estimated 21,700 high-durability new poles are required each year, representing further investment of 13.5 million dollars per year. Yet, agreements which progressively phase out logging of native forests around Australia have been signed, giving the industry about 25 years to make the transition from Crown native forests to plantations and private forests. As utility poles were traditionally cut from native forest hardwood species, finding solutions to source new poles currently presents a challenge. This paper presents tests on Veneer Based Composite hardwood hollow utility poles manufactured from Gympie messmate (Eucalyptus cloeziana) plantation thinning. Small diameter poles of nominal 115 mm internal diameter and 15 mm wall-thickness were manufactured in two half-poles butt jointed together, using 9 veneers per halfpole. The poles were tested in bending and shear, and experimental test results are presented. The mechanical performance of the hollow poles is discussed and compared to hardwood poles cut from mature trees and of similar size. Future research and different options for improving the current concept are proposed in order to provide a more reliable and cost effective technical solution to the current shortage of utility poles. © RILEM 2014.

Development and testing of allometric equations for estimating above-ground biomass of mixed-species environmental plantings

To quantify the impact that planting indigenous trees and shrubs in mixed communities (environmental plantings) have on net sequestration of carbon and other environmental or commercial benefits, precise and non-biased estimates of biomass are required. Because these plantings consist of several species, estimation of their biomass through allometric relationships is a challenging task. We explored methods to accurately estimate biomass through harvesting 3139 trees and shrubs from 22 plantings, and collating similar datasets from earlier studies, in non-arid (>300mm rainfallyear-1) regions of southern and eastern Australia. Site-and-species specific allometric equations were developed, as were three types of generalised, multi-site, allometric equations based on categories of species and growth-habits: (i) species-specific, (ii) genus and growth-habit, and (iii) universal growth-habit irrespective of genus. Biomass was measured at plot level at eight contrasting sites to test the accuracy of prediction of tonnes dry matter of above-ground biomass per hectare using different classes of allometric equations. A finer-scale analysis tested performance of these at an individual-tree level across a wider range of sites. Although the percentage error in prediction could be high at a given site (up to 45%), it was relatively low (<11%) when generalised allometry-predictions of biomass was used to make regional- or estate-level estimates across a range of sites. Precision, and thus accuracy, increased slightly with the level of specificity of allometry. Inclusion of site-specific factors in generic equations increased efficiency of prediction of above-ground biomass by as much as 8%. Site-and-species-specific equations are the most accurate for site-based predictions. Generic allometric equations developed here, particularly the generic species-specific equations, can be confidently applied to provide regional- or estate-level estimates of above-ground biomass and carbon. © 2013 Elsevier B.V.

Use of a proposed antimicrobial susceptibility testing method for Haemophilus parasuis

The aim of this study was to examine the antimicrobial susceptibility of 97 Haemophilus parasuis cultured from Australian pigs. As there is no existing standard antimicrobial susceptibility technique available for H. parasuis, methods utilising the supplemented media, BA/SN for disc diffusion and test medium broth (TMB) for a microdilution technique, were initially evaluated with the reference strains recommended by the Clinical and Laboratory Standards Institute. The results of the media evaluation suggested that BA/SN and TMB can be used as suitable media for susceptibility testing of H. parasuis. The proposed microdilution technique was then used with 97 H. parasuis isolates and nine antimicrobial agents. The study found that Australian isolates showed elevated minimum inhibitory concentrations (MICs) for ampicillin (1%), penicillin (2%), erythromycin (7%), tulathromycin (9%), tilmicosin (22%), tetracycline (31%) and trimethoprim-sulfamethoxazole (40%). This study has described potential antimicrobial susceptibility methods for H. parasuis and has detected a low percentage of Australian H. parasuis isolates with elevated antimicrobial MICs.

Top-predator control-induced trophic cascades: an alternative hypothesis to the conclusion of Colman et al.

Recently argued that observed positive relationships between dingoes and small mammals were a result of top-down processes whereby lethal dingo control reduced dingoes and increased mesopredators and herbivores, which then suppressed small mammals. Here, I show that the prerequisite negative effects of dingo control on dingoes were not shown, and that the same positive relationships observed may simply represent well-known bottom-up processes whereby more generalist predators are found in places with more of their preferred prey. Identification of top-predator controlinduced trophic cascades first requires demonstration of some actual effect of control on predators, typically possible only through manipulative experiments with the ability to identify cause and effect.

A novel and effective technology for mitigating nitrous oxide emissions from land-applied manures

Land-applied manures produce nitrous oxide (N2O), a greenhouse gas (GHG). Land application can also result in ammonia (NH3) volatilisation, leading to indirect N2O emissions. Here, we summarise a glasshouse investigation into the potential for vermiculite, a clay with a high cation exchange capacity, to decrease N2O emissions from livestock manures (beef, pig, broiler, layer), as well as urea, applied to soils. Our hypothesis is that clays adsorb ammonium, thereby suppressing NH3 volatilisation and slowing N2O emission processes. We previously demonstrated the ability of clays to decrease emissions at the laboratory scale. In this glasshouse work, manure and urea application rates varied between 50 and 150 kg nitrogen (N)/ha. Clay : manure ratios ranged from 1 : 10 to 1 : 1 (dry weight basis). In the 1-year trial, the above-mentioned N sources were incorporated with vermiculite in 1 L pots containing Sodosol and Ferrosol growing a model pasture (Pennisetum clandestinum or kikuyu grass). Gas emissions were measured periodically by placing the pots in gas-tight bags connected to real-time continuous gas analysers. The vermiculite achieved significant (P ≤ 0.05) and substantial decreases in N2O emissions across all N sources (70% on average). We are currently testing the technology at the field scale; which is showing promising emission decreases (~50%) as well as increases (~20%) in dry matter yields. This technology clearly has merit as an effective GHG mitigation strategy, with potential associated agronomic benefits, although it needs to be verified by a cost–benefit analysis.