Pasture dieback: December 2019 update

In early 2017, producers from across parts of central Queensland reported widespread dieback of pastures. In 2019, there have been two further suspected occurrences in northern NSW.

As a result of these occurrences and producer concerns about pasture dieback, MLA – with the support of the Australian Government – initiated a plan to address the issue.

See below for:

• A summary of findings to date
• Key focus areas under the pasture dieback Australian Government grant
• Next steps.

Pasture dieback research findings to date

1. Mealybugs have been widely detected on dieback pastures and are now considered to be the leading potential causal agent.
2. Legumes are not affected by mealybugs; spring and summer-sown forage crops are a short-term solution.
3. Cultivating and re-sowing pasture with insecticide treated seed and fertiliser gave a positive response, with no sign of dieback recurring.
4. Fungal pathogens are not the primary cause of pasture dieback.
5. Weather and soil conditions may be related to the spread of dieback.
6. There is potential to use satellite mapping to detect dieback spread patterns.
7. Hyperspectral imaging has been used to analyse dieback-affected grasses for early detection. Variability is apparent, with additional lab and field work required.

Focus areas under the pasture dieback Australian Government grant

• The research grant from the Australian Government is targeting causes, detection, monitoring and solutions, including:
• biology of mealybugs – identification of species, growth and reproduction cycle
• mealybug interactions with grasses (infestation to death)
• other potential causal agents of pasture dieback
• identification of any natural enemies for long-term, cost-effective control
• cost-effective chemical solutions
• resistant grass varieties and endophytes against dieback causal agents
• detection and monitoring approaches
• working collaboratively – sharing information and communication of management options
• engaging producers – to be increasingly involved in dieback awareness, broad-based communications and the mapping of where dieback is occurring.

Next steps

Moving forward, MLA will continue to work with a range of research providers, producer networks and the Queensland and NSW Governments to capture and exchange information, and will support producers to take action on-farm.

The work will revolve around:

• Industry engagement and communication – updating existing information
• Defining dieback at scale, mapping and spread
• Research into causal agents
• Identifying and sharing effective management options.

As information becomes available, it will be communicated via MLA’s pasture dieback hub and through research partners. Updates will also be sent out in the pasture dieback e-newsletter.

More information

Subscribe to MLA’s Pasture Dieback Update e-newsletter, which provides up-to-date news and information to producers affected by dieback.