Development of sustainable management for Pimelea and pimelea poisoning

Toxic Pimelea species (desert riceflower) are naturally occurring species found throughout beef cattle regions of Queensland, New South Wales, South Australia and the Northern Territory. Three species of Pimelea (simplex, elongata, and trichostachya) are poisonous to livestock and potentially fatal to cattle, with serious economic consequences through the loss of production, stock deaths and the costs of agistment. A better understanding of the ecology of the plant/disease is required to develop best practice to manage Pimelea in cattle-producing areas. Development of a chemical assay for the toxin (simplexin) is a key component of the current research project enabling toxin levels to be related to stage of plant growth, environmental and climatic factors.

Virus identification and development of long-term management strategies for the rhubarb industry

The purpose of this report is to present the final results of all activities conducted under HAL Project VG05053 ‘Virus identification and development of long-term management strategies for the rhubarb industry’. The report provides a summary of project findings, a description of technology transfer activities, and recommendations arising from the outcomes of the project. The overall objective of this project was to devise a strategy for the control of rhubarb decline disease through 1) knowledge of the viruses present and their epidemiology, 2) production of virus-free planting material via tissue culture, and 3) formation of a national grower group to represent industry.

Development of commercial application of an avocado fruit robustness test

Fruit quality is one of the major factors limiting growth in avocado retail sales. Avocado growers are often unaware of their end-use fruit quality since quality problems only manifest upon fruit ripening and growers receive limited feedback from the supply chain. If growers were aware of their expected fruit quality they would be equipped to make better marketing decisions and if necessary to take remedial actions to improve their fruit quality. Avotest is being developed as a quick and easy method of determining expected end-use fruit quality before the start of the commercial fruit harvest. The test aims at distinguishing between blocks with robust fruit and those with less robust fruit. The test could also be used to predict the resulting fruit quality after the implementation of new farming practices.

Towards the Development of a Functional-Structural model for Macadamia

Towards the Development of a Functional-Structural model for Macadamia.

Development of an avocado rapid library tray system for Hass

The aim of the project is to develop a rapid ripening protocol/test which can be used as a reliable library tray system for Hass Avocados. Fruit will be taken from the end of the packing line to reflect both commercial handling quality and intrinsic fruit quality.

Development of pedigree mapping for wheat

The aim of this project is to build on the work done so far in applying pedigree mapping principals to northern adapted wheat pedigreed to identify robust QTL for quality traits.

Resistance to root-lesion Nematodes for development of molecular markers

This is a sub-project of the Australian Wheat and Barley Molecular Marker Program funded by GRDC and led by Drs Diane Mather and Ken Chalmers of University of Adelaide. In this sub-project we will supply phenotypic data on resistance to two species of root-lesion nematodes (Pratylenchus thornei and P. neglectus) on several populations of wheat doubled haploids. We will also supply existing genotypic data on one doubled haploid population. We will also test one population of doubled haploids (CPI133872/Janz) a second time for resistance to P. thornei and P. neglectus and supply this information to University of Adelaide for the development of molecular markers for use by wheat breeders in selecting for resistance to root-lesion nematodes.

Development of diagnotic capacity for Cotton Leaf Roll Virus from Thailand

Viral diseases of cotton are of economic significance in many parts of the world and several of these remain biosecurity threats to the Australian cotton industry, including Cotton Leaf Roll Virus (CLRV) from South East Asia. The proposed project will result in a greater understanding of the field symptoms of CLRV in Thailand and diagnostic assays used for its detection. I will also determine if the diagnostic assay being developed for Brazilian CLRDV as part of the CRDC project (11-12FRP00062) may also detect Thailand CLRV. It will provide educational opportunities to increase the knowledge base of staff currently working on cotton virus research and in doing so help to protect the Australian cotton industry from incursions of exotic viruses.

Addressing the demand for feed grains through the development of high yielding

Development and evaluation of high yielding feed wheat grermplasm.

Objective `Safe' Grazing Capacities for South-West Queensland Australia: Development of a Model for Individual Properties

Few tools are available to assist graziers, land administrators and financiers in making objective grazing capacity decisions on Australian rangelands, despite existing knowledge regarding stocking rate theory and the impact of stocking rates on land condition. To address this issue a model for objectively estimating 'safe' grazing capacities on individual grazing properties in south-west Queensland was developed. The method is based on 'safe' levels of utilisation (15%-20%) by domestic livestock of average annual forage grown for each land system on a property. Average annual forage grown (kglha) was calculated as the product of the rainfall use efficiency (kglhdmm) and average annual rainfall (mm) for a land system. This estimate included the impact of tree and shrub cover on forage production. The 'safe' levels of forage utilisation for south- west Queensland pastures were derived from the combined experience of (1) re-analysis of the results of grazing trials, (2) reaching a consensus on local knowledge and (3) examination of existing grazing practice on 'benchmark' grazing properties. We recognise the problems in defining, determining and using grazing capacity values, but consider that the model offers decision makers a tool that can be used to assess the grazing capacity of individual properties.

Evaluation of super-heated steam vacuum drying viability and development of a predictive drying model for four Australian hardwood species.

The results of drying trials show that vacuum drying produces material of the same or better quality than is currently being produced by conventional methods within 41 to 66 % of the drying time, depending on the species. Economic analysis indicates positive or negative results depending on the species and the size of drying operation. Definite economic benefits exist by vacuum drying over conventional drying for all operation sizes, in terms of drying quality, time and economic viability, for E. marginata and E. pilularis. The same applies for vacuum drying C. citriodora and E. obliqua in larger drying operations (kiln capacity 50 m3 or above), but not for smaller operations at this stage. Further schedule refinement has the ability to reduce drying times further and may improve the vacuum drying viability of the latter species in smaller operations.

Development of a productivity asessment toll for native spotted gum forest on private land based on estimates of forest growth on Crown land.

Reliable estimates of forest productivity are essential for improved predictions of timber yields for the private native spotted gum resource in southern Qld and northern NSW. The aim of this research was to estimate the potential productivity of native spotted gum forests on private land by making use of available inventory data collated from Qld and northern NSW for spotted gum forest on Crown land (i.e. state forests). We measured a range of site-related factors to determine their relative importance in predicting productivity of spotted gum forest. While measures such as stand height and height-diameter relationships are known to be useful predictors of productivity, we aimed to determine productivity for a site where this information was not available. Through estimation of stand growth rates we developed a spotted gum productivity assessment tool (SPAT) for use by landholders and extension officers. We aimed to develop a tool to allow private landholders to see the benefits of maintaining their timber resource. This paper summarises the information used to develop the SPAT with a particular focus on forest growth relationships.

Bovine cysticercosis-Development of a real-time PCR to enhance classification of suspect cysts identified at meat inspection

Laboratory confirmation methods are important in bovine cysticerosis diagnosis as other pathologies can result in morphologically similar lesions resulting in false identifications. We developed a probe-based real-time PCR assay to identify Taenia saginata in suspect cysts encountered at meat inspection and compared its use with the traditional method of identification, histology, as well as a published nested PCR. The assay simultaneously detects T. saginata DNA and a bovine internal control using the cytochrome c oxidase subunit 1 gene of each species and shows specificity against parasites causing lesions morphologically similar to those of T. saginata. The assay was sufficiently sensitive to detect 1 fg (Ct 35.09 +/- 0.95) of target DNA using serially-diluted plasmid DNA in reactions spiked with bovine DNA as well as in all viable and caseated positive control cysts. A loss in PCR sensitivity was observed with increasing cyst degeneration as seen in other molecular methods. In comparison to histology, the assay offered greater sensitivity and accuracy with 10/19 (53%) T. saginata positives detected by real-time PCR and none by histology. When the results were compared with the reference PCR, the assay was less sensitive but offered advantages of faster turnaround times and reduced contamination risk. Estimates of the assay's repeatability and reproducibility showed the assay is highly reliable with reliability coefficients greater than 0.94. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.

Inheritance and relative dominance, expressed as toxicity response and delayed development, of phosphine resistance in immature stages of Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae)

Fumigation of stored grain with phosphine (PH 3) is used widely to control the lesser grain borer Rhyzopertha dominica. However, development of high level resistance to phosphine in this species threatens control. Effective resistance management relies on knowledge of the expression of resistance in relation to dosage at all life stages. Therefore, we determined the mode of inheritance of phosphine resistance and strength of the resistance phenotype at each developmental stage. We achieved this by comparing mortality and developmental delay between a strongly resistant strain (R-strain), a susceptible strain (S-strain) and their F 1 progenies. Resistance was a maternally inherited, semi-dominant trait in the egg stage but was inherited as an autosomal, incompletely recessive trait in larvae and pupae. The rank order of developmental tolerance in both the sensitive and resistant strains was eggs > pupae > larvae. Comparison of published values for the response of adult R. dominica relative to our results from immature stages reveals that the adult stage of the S-strain is more sensitive to phosphine than are larvae. This situation is reversed in the R-strain as the adult stage is much more resistant to phosphine than even the most tolerant immature stage. Phosphine resistance factors at LC 50 were eggs 400×, larvae 87× and pupae 181× with respect to reference susceptible strain (S-strain) adults indicating that tolerance conferred by a particular immature stage neither strongly nor reliably interacts with the genetic resistance element. Developmental delay relative to unfumigated control insects was observed in 93% of resistant pupae, 86% of resistant larvae and 41% of resistant eggs. Increased delay in development and the toxicity response to phosphine exposure were both incompletely recessive. We show that resistance to phosphine has pleiotropic effects and that the expression of these effects varies with genotype and throughout the life history of the insect. © 2012.