Quantitative microbial risk assessment modelling for the use of reclaimed water in irrigated horticulture

Reuse of treated sewage effluent for the irrigation of horticultural crops is being propounded and practiced as a means of alleviating pressure on freshwater resources. Concerns have been raised. however, as to the risk to human health, primarily disease, associated with this practice. Quantitative Microbial Risk Assessment (QMRA) is a useful tool for estimating this risk. We describe how QMRA works and the current state of knowledge of the components of QMRA models for the horticultural reuse scenario.

The origins, development and perceived effectiveness of horticulture-based therapy in Victoria

 This study found that horticulture based therapy in Victoria provides a wide range of benefits in health and community settings. Programs were largely informal and provided by dedicated individuals. A higher profile and professional systems and structure would assist therapeutic horticulture to reach its potential in Victoria.

Layered vulnerability: Temporary migrants in Australian horticulture

Australian horticulture (fruit and vegetable production) relies upon a seasonal harvest workforce, much of which now consists of temporary migrant workers. This article argues that the composition of this workforce and the character of the work lead towards layered vulnerability, some groups being more exposed to low pay and substandard working conditions than others. Formally at least, employment conditions are generally protected by the federal Horticulture Award (2010). But are decent employment standards consistently observed? The article explores this question, examining three issues. First, does analysis of workforce composition reveal different tiers in the workforce, some more vulnerable than others? Second, do the casual nature of harvest work and the job search processes used by temporary migrant workers create disadvantaged groups? Third, does evidence about pay, working hours and work intensity reveal some workers to be more vulnerable than others? The article concludes with an examination of those factors that appear to be associated with layered vulnerability in the harvest workforce, and considers some policy implications.

Migration intermediaries and codes of conduct: temporary migrant workers in Australian horticulture

Over recent decades, developments in network governance have seen governments around the world cede considerable authority and responsibility to commercial migration intermediaries for recruiting and managing temporary migrant labour. Correspondingly, a by-product of network governance has been the emergence of soft employment regulation in which voluntary codes of conduct supplement hard (enforceable) legal employment standards. This paper explores these developments in the context of temporary migrant workers employed in Australian horticulture. First the paper analyses the growing use of temporary migrant labour in this industry. It then describes how different types of intermediaries interact with this workforce. The paper then outlines both hard and soft employment regulations, and contrasts them with actual employment conditions, questioning how a network governance approach has affected this vulnerable workforce. The paper concludes that changes in network governance of migration and employment relations have emasculated formal legal regulation, leaving market forces to operate without effective or ethical constraints at the expense of the public good.

Faster, richer, better: rapid appraisal techniques for the study of IS implementation in virtual communities

A major issue in Information Systems (IS) research is how to combine relevance and rigor (Benbasat and Zmud, 1999) and reduce the widening gap between research results and adoption (Dunn, 1994). Qualitative researchers make use of interpretivist methods to add richness and depth to their understanding of user problems. Interpretivist methods applied to IS implementations can thus result in research which communicates those findings more effectively. However standard interpretivist data-collection and analysis methods can be time-consuming and expensive. Findings based on these methods may be irrelevant to practitioners by the time they reach publication stage. A potential solution to this problem lies in Rapid Appraisal or RA, a qualitative appraisal methodology derived from rural development-related research. It offers IS researchers an additional technique for learning and acquiring relevant information in a limited period of time that  supplements current data collection and analysis techniques. RA adds value to the traditional approach for studying diffusion of innovation, supporting and extending the IS researcher’s qualitative ‘tool-kit’. In this paper we review an electronic gateway designed to facilitate the diffusion of an Australian government to business [G2B] export documentation system, EXDOC, which was first implemented with meat producers. RA techniques were used to collect and analyse data regarding the implementation of the first regional Electronic Trade Facilitation Center [ETFC] successfully established for Australian exporters in the horticulture sector. The findings from the original EXDOC implementation in the meat sector were confirmed and extended through this study. These include the importance of developing a governance structure that ensures all community members share the benefits of an implementation and the fact that virtual trading communities are attractive to users only if they add value to their business and extend standard ways of operating. Interactive interviews, part of the RA approach; also enabled us to expand our understanding of the way in which procedures developed in the course of implementing an electronic market represent value-adding opportunities for virtual trading communities. The paper has special relevance for researchers investigating adoption and diffusion issues experienced by small-scale producers with low exposure to technology in remote and rural settings.

Is the risk of illness through consuming vegetables irrigated with reclaimed wastewater different for different population groups?

The use of reclaimed wastewater for irrigation of horticultural crops is commonplace in many parts of the world and is likely to increase. Concerns about risks to human health arising from such practice, especially with respect to infection with microbial pathogens, are common. Several factors need to be considered when attempting to quantify the risk posed to a population, such as the concentration of pathogens in the source water, water treatment efficiency, the volume of water coming into contact with the crop, and the die-off rate of pathogens in the environment. Another factor, which has received relatively less attention, is the amount of food consumed. Plainly, higher consumption rates place one at greater risk of becoming infected. The amount of vegetables consumed is known to vary among ethic groups. We use Quantitative Microbial Risk Assessment Modelling (QMRA) to see if certain ethnic groups are exposed to higher risks by virtue of their consumption behaviour. The results suggest that despite the disparities in consumption rates by different ethnic groups they generally all faced comparable levels of risks. We conclude by suggesting that QMRA should be used to assess the relative levels of risk faced by groups based on divisions other than ethnicity, such as those with compromised immune systems.

Opportunities for reclaimed water use in Australian agriculture

This paper provides an overview of how Australia exploits its water resources with a focus on reclaimed water. Arguments are brought up for the high value horticultural sector (vegetables, fruits and grapes) being a competitive customer for reclaimed water. Factors to consider when assessing the suitability for reclaimed water use in horticulture either for substitution of existing water resources or expansion of production are discussed.

Potassium phosphonate alters the defence response of Xanthorrhoea australis following infection by Phytophthora cinnamomi

Potassium phosphonate (phosphite) is widely used in the management of Phytophthora diseases in agriculture, horticulture and natural environments. The Austral grass tree, Xanthorrhoea australis, a keystone species in the dry sclerophyll forests of southern Australia, is susceptible to Phytophthora cinnamomi, but is protected by applications of phosphite. We examined the effect of phosphite application on the infection of X. australis seedlings and cell suspension cultures by zoospores of P. cinnamomi. Phosphite induced more intense cellular responses to pathogen challenge and suppressed pathogen ingress in both seedlings and cell cultures. In untreated X. australis seedlings, hyphal growth was initially intercellular, became intracellular 24 h after inoculation, and by 48 h had progressed into the vascular tissue. In phosphite-treated seedlings, growth of P. cinnamomi remained intercellular and was limited to the cortex, even at 72 h after inoculation. The cell membrane retracted from the cell wall and phenolic compounds and electron dense substances were deposited around the wall of infected and neighbouring cells. Suspension cells were infected within 6 h of inoculation. Within 24 h of inoculation, untreated cells were fully colonised, had collapsed cytoplasm and died. The protoplast of phosphite-treated suspension cells collapsed within 12 h of inoculation, and phenolic material accumulated in adjacent, uninfected cells. No anatomical response to phosphite treatment was observed before infection of plant tissues, suggesting that the phosphite-associated host defence response is induced following pathogen challenge. Anatomical changes provide evidence that phosphite stimulates the host defence system to respond more effectively to pathogen invasion.