Towards the development of an Australian cobia aquaculture industry

The project builds on successful industry collaborations in 2008 and 2009 to research key hatchery, production and marketing issues for cobia production in Queensland. Pacific Reef Fisheries and Ecofish International have identified cobia production as long term company goals and see the research and technology transfer in the project as a key part of this development.

Optimising plant bed performance through adaptive research with the Australian sweetpotato industry

A key driver of Australian sweetpotato productivity improvements and consumer demand has been industry adoption of disease-free planting material systems. On a farm isolated from main Australian sweetpotato areas, virus-free germplasm is annually multiplied, with subsequent 'pathogen-tested' (PT) sweetpotato roots shipped to commercial Australian sweetpotato growers. They in turn plant their PT roots into specially designated plant beds, commencing in late winter. From these beds, they cut sprouts as the basis for their commercial fields. Along with other intense agronomic practices, this system enables Australian producers to achieve worldRSQUOs highest commercial yields (per hectare) of premium sweetpotatoes. Their industry organisation, ASPG (Australian Sweetpotato Growers Inc.), has identified productivity of mother plant beds as a key driver of crop performance. Growers and scientists are currently collaborating to investigate issues such as catastrophic plant beds losses; optimisation of irrigation and nutrient addition; rapidity and uniformity of initial plant bed harvests; optimal plant bed harvest techniques; virus re-infection of plant beds; and practical longevity of plant beds. A survey of 50 sweetpotato growers in Queensland and New South Wales identified a substantial diversity in current plant bed systems, apparently influenced by growing district, scale of operation, time of planting, and machinery/labour availability. Growers identified key areas for plant bed research as: optimising the size and grading specifications of PT roots supplied for the plant beds; change in sprout density, vigour and performance through sequential cuttings of the plant bed; optimal height above ground level to cut sprouts to maximise commercial crop and plant bed performance; and use of structures and soil amendments in plant bed systems. Our ongoing multi-disciplinary research program integrates detailed agronomic experiments, grower adaptive learning sites, product quality and consumer research, to enhance industry capacity for inspired innovation and commercial, sustainable practice change.

The use of temperate species in the Australian subtropics.

Temperate species and tropical crop silage are the basis for forage production for the dairy industry in the Australian subtropics. Irrigation is the key resource needed for production, with little survival of temperate species under rain-grown conditions except for lucerne. Annual ryegrass (Lolium multiflorum), fertilised with either inorganic nitrogen or grown with clovers, is the main cool season forage for the dairy industry. It is sown into fully prepared seedbeds, oversown into tropical grasses, especially kikuyu (Pennisetum clandestinum) or sown after mulching. There has been a continual improvement in the performance of annual and hybrid ryegrass cultivars over the last 25 years. In small plot, cutting experiments, yields of annual ryegrass typically range from 15 to 21 t DM/ha, with equivalent on-farm yields of 7 to 14 t DM/ha of utilised material. Rust (Puccinia coronata) remains the major concern although resistance is more stable than in oats. There have also been major improvements in the performance of perennial ryegrass (L. perenne) cultivars although their persistence under grazing is insufficient to make them a reliable forage source for the subtropics. On the other hand, tall fescue (Festuca arundinacea) and prairie grass (Bromus willdenowii) cultivars perform well under cutting and grazing, although farmer resistance to the use of tall fescue is strong. White clover (Trifolium repens) is a reliable and persistent performer although disease usually reduces its performance in the third year after sowing. Persian (Shaftal) annual clover (T. resupinatum) gives good winter production but the performance of berseem clover (T. alexandrinum) is less reliable and the sub clovers (T. subterraneum) are generally not suited to clay soils of neutral to alkaline pH. Lucerne (Medicago sativa), either as a pure stand or in mixtures, is a high producing legume under both irrigation and natural rainfall. Understanding the importance of leaf and crown diseases, and the development of resistant cultivars, have been the reasons for its reliability. Insects on temperate species are not as serious a problem in the subtropics as in New Zealand (NZ). Fungal and viral diseases, on the other hand, cause many problems and forage performance would benefit from more research into resistance.

Climate Change - Risks and Opportunities for the Custard Apple Industry

Climate affects the custard apple industry in a range of ways through impacts on growth, disease risk, fruit set and industry location. Climates in Australia are influenced by surrounding oceans, and are very variable from year to year. However, amidst this variability there are significant trends, with Australian annual mean temperatures increasing since 1910, and particularly since 1950, with night-time temperatures increasing faster (0.11oC/decade) than daytime temperatures (0.06oC/decade). These temperature increases and other climate changes are expected to continue as a result of greenhouse gas emissions, with ongoing impacts on the custard apple industry. Five sites were chosen to assess possible future climate changes : Mareeba, Yeppoon, Bundaberg, Nambour and Lismore, these sites representing the extent of the majority of custard apple production in eastern Australia. A fifth site (Coffs Harbour) was selected as it is south of the current production regions. A mean warming of 0.8 to 1.2oC is anticipated over most of these sites by the year 2030, relative to 1990. This paper assesses the potential effects of climate change on custard apple production, and suggests strategies for adaptation.

Exotic plant pests–a threat to the sustainability of Australia’s grains industry

Exotic plant pests (EPPs) threaten production, market access and sustainability of Australian plant production systems. For the grains industry there are over 600 identified EPPs of which 54 are considered high priority, posing a significant threat. Despite Australia’s geographical isolation and strong quarantine systems, the threat from EPPs has never been higher with the increasing levels of travel and trade, emphasising the need for improving our efforts in prevention, preparedness and surveillance for EPPs.

Improvement and Maintenance of Turf Demonstration Plots

DEEDI have built and maintained a living library of turf grass selections of 138 different turf cultivars. Material is also preserved in tubs in a protected growing environment. The maintenance and ongoing upgrading of these plots requires significant resources to maintain their integrity. As the plots have been in place since 2000, they are currently in need of significant repair. This project will assist in the improvement and maintenance of the turf library for the benefit of the turf industry producers and Australian turf research more generally.