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Pasture Dieback

The red meat and livestock industry is working in close collaboration to respond to the on-farm challenges presented by pasture dieback. MLA, Queensland Department of Agriculture and Fisheries and NSW Department of Primary Industries are working alongside red meat producers, research institutions, peak industry councils and state farming organisations to ensure ongoing investment in pasture dieback research is effective, well-coordinated and clearly communicated.

On this page:

What is pasture dieback?

Pasture dieback is a condition which causes the death of sown and native pastures by affecting plant health and function, reducing the productivity of affected properties. It has been observed in a range of soil types and plant species across Queensland and northern NSW.

The condition occurs episodically, with the current outbreak first identified in early 2015 and spreading across eastern Queensland in subsequent years. In early 2020, pasture dieback was also confirmed in northern NSW. 

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A pasture dieback-affected paddock of buffel grass in Barallabra, Queensland

How to identify pasture dieback

The symptoms of pasture dieback generally occur initially as patches in otherwise seemingly healthy pastures. If a producer suspects pasture dieback on their property, they should be on the look-out for:

  • vivid yellowing, reddening or bronzing of the leaves, starting from the tip and progressing down towards the ligule (the symptoms develop first on the oldest leaves, but eventually spread to the whole plant)
  • reduction in root system and grass density
  • plants that become unthrifty and eventually die
  • pastures that become grey and disintegrate once dead
  • cattle avoiding affected plants.

Initially, patches of dieback are roughly circular, ranging from 2–60m in diameter. These areas can grow irregularly, spreading at speeds ranging from slow (cm2/week in the dryer, colder months) to rapid (ha/week in the wetter, warmer months). Multiple patches can coalesce to form large, dead areas.

Producers have also observed that dieback is most severe in areas of long grass with large amounts of thatching – for example, under fence lines or areas of low pasture utilisation.

North Burnett 2 - 300x230.jpgBunderberg - 300x230.jpgSouth East Queensland - 300x230.jpgFenceline - 300x230.jpg

Affected regions

What regions are affected?

Reliable estimates of pasture affected by dieback are currently not available, however, AgForce has predicted the outbreak to cover a large area of productive Queensland, with estimates ranging between 400,000 and 4.4 million hectares.

The below map shows the approximate areas pasture dieback has been reported in. However, it does not indicate how prevalent pasture dieback is in each region, as this information is currently not available.

Affected area - 480x500.jpg

What pasture species have been affected?

Queensland

The main species which have been affected in Queensland are:

  • Buffel grass
  • Sabi grass
  • Creeping blue grass
  • Rhodes grass
  • Panics
  • Paspalum
  • Signal grass
  • Para grass
  • Pangola grass
  • Seteria
  • Black spear Grass
  • Forest blue grass
  • Golden beard grass

Source: QDAF

NSW

The main species which have been affected in northern NSW are:

  • Broad leaf paspalum
  • Bahia grass
  • Giant paspalum
  • Setaria cv Kazungula
  • Rhodes grass cv Katambora
  • Couch*
  • Kikuyu*
  • Carpet grass*

* denotes pastures which have only shown symptoms, and not pasture death.
Source: NSW DPI

North Bunnett - 300x230.jpgMaryborough - 300x230.jpgNorthern NSW - 300x230.jpgDead buffel - 300x230.jpg

 

 

Frequently asked questions

Q. What is the cause of pasture dieback?

A. Although it is not definitive, there are strong indications that pasture mealybugs (Heliococcus summervillei) are the leading cause of dieback. However, research also indicates there are secondary causal factors at play, and understanding these is key to understanding why episodic outbreaks occur.

Q. Are there any known treatments and chemicals that can control pasture dieback?

A. Currently there are no APVMA approved and registered chemicals which can be used to treat pasture dieback.

Q. How fast can pasture dieback spread?

A. Patches of dieback are initially roughly circular, ranging from 2–60m in diameter. These areas can grow irregularly, spreading at speeds ranging from slow (cm2/week in the dryer, colder months) to rapid (ha/week in the wetter, warmer months). Multiple patches can coalesce to form large, dead areas.

Q. Are there other types of dieback?

A. Yes. As a generalised name, dieback can affect a range of plants and as a disease is identified when large areas of plants die without an obvious cause. Dieback has been reported in plants including eucalypts, salt marshes, woody weeds, orchard trees and turf grass.

The cause of dieback across different plants is not consistent, however, examples from other types of dieback may provide guidance for research into pasture dieback.

MLA's role

MLA’s role in addressing pasture dieback

MLA is working with industry bodies, state departments and researchers across affected regions to ensure a coordinated approach to investment in research, development, extension and adoption is being taken to support producers in combatting dieback.

MLA’s objective is to ensure pasture dieback research and development is focused on finding solutions for those affected by it and to provide valuable, up-to-date information to producers as it comes to hand.

A key focus is supporting the delivery of short-term solutions to feed livestock while a permanent solution to pasture dieback is investigated.

The Queensland Department of Agriculture and Fisheries and NSW Department of Primary Industries have key roles within their state jurisdictions to undertake measures to control the outbreak of pasture dieback. Through its industry-focused response, MLA is supporting these organisations to do so.

Research and development

In mid-2019, the Department of Agriculture, Water and the Environment awarded a $2.7 million grant to MLA to undertake research and development activities to further understand pasture dieback, with a focus on determining the role of mealybugs in the presence of dieback-affected pastures. MLA has committed to matching this grant with producer levy investment to ensure solutions-focused research, development and adoption activities are undertaken to support the industry.

MLA’s plan on a page summarises the federal grant work plan and MLA’s direction in its response to pasture dieback.

A central component of investment so far has centred around understanding mealybugs as the leading causal agent of dieback. However, MLA’s understanding is that there are other secondary factors which contribute to the episodic outbreaks of dieback that occur. Some of the new projects are focused on understanding these factors to better tailor solutions while investigations into the mealybug continue.

Research partners:

  • Queensland Department of Agriculture and Fisheries (QDAF)
  • New South Wales Department of Primary Industries (NSW DPI)
  • Applied Horticulture Research
  • University of Queensland (UQ)
  • Queensland University of Technology (QUT).

MLA's pasture dieback governance

Past work conducted on pasture dieback:

  • Field trials to test interventions – Cultivating and re-sowing pasture with insecticide treated seed and fertiliser gave the best response with no sign of dieback recurring.
  • Survey of soils and plants from dieback-affected areas to determine role of soil-based organisms – fungal pathogens are not the primary cause of pasture dieback.
  • Studies examining establishment and spread of pasture dieback – how recent weather, soil conditions and other factors may be related to spread.
  • Genomic DNA investigation of affected soils.
  • Satellite mapping to detect dieback – potential to build a “trend pattern”. These patterns point towards rain as having a direct effect on dieback.
  • Hyperspectral imaging – to analyse dieback-affected grasses for early detection. Variability is apparent, with additional lab and field work required.
  • Mealybug studies – mealybugs have been widely detected on dieback pastures. The biology of the mealybug and management is being investigated.
  • Evaluation of pasture species and resistance to mealybugs – legumes are not affected; spring and summer-sown forage crops are a short-term solution.
  • Producer interviews – to collect information about how dieback was occurring on each property, and any observations by producers on potential causes and control practices which have been trialled. 

Current projects:*

  • QUT – Understanding the mealybug life cycle and history. This project will look at the biology of the mealybug – growth, reproduction, seasonal interaction with grasses, to help understand possible natural enemies, particularly possible parasitoids and pathogens.
  • QUT – Bioassays and controls. This project will provide definitive tests to determine the progress of dieback in a range of grasses from initial infestation to death of the grass, and any association with pathogens that may lead to dieback. This information will assist with the screening of potential controls for mealybugs.
  • QUT – Evaluation of potential for use of endophytes as a control measure. This project aims to identify grass varieties tolerant of pasture dieback, with or without endophytes, to regenerate pastures and enable long-term recovery.
  • QDAF – Grazier engagement to increase knowledge, skills and ability to combat pasture dieback. The project will facilitate the formation of a red meat producer group in central Queensland to build knowledge and skills to implement changes on-farm to better manage pasture dieback impacts.
  • QDAF – Comprehensive diagnostic analysis of pasture affected dieback. This project will explore and better understand other possible factors causing pasture dieback outbreaks.
  • Applied Horticulture Research – Management options and species evaluation to increase productivity in dieback affected pastures. This project will reassess MLA-funded field trials after two years to quantify any longer-term benefits and evaluate pasture species and/or varieties with reported tolerance to pasture dieback which producers could use to replant dieback-affected pastures.
  • UQ – Determining the role of ground pearls. The project will determine if the presence of ground pearls is consistent across dieback sites and understand what role they may have in causing dieback.
  • QUT – Spatio-temporal prediction of pasture dieback using UAVs and remote sensing. This proof of concept project will integrate remotely sensed imagery from unmanned aerial vehicles (UAVs) and satellite-based platforms to identify spectral signatures of dieback for cost effective identification, mapping and monitoring over time and at scale using satellite-based systems.
  • QUT – Rapid diagnosis of pasture dieback using SIFT-MS. This project will test the proof of concept of the rapid analysis of Volatile Organic Compounds (VOC) and chemical markers detected by Mass Spectrometry (MS) for the rapid identification of pasture dieback in both laboratory-induced dieback (using mealybugs) and on field samples using a portable device for gas collection.

* Project partners work together across affected sites and collaboration occurs when work overlaps and interlinks. MLA’s role is to facilitate this collaboration. Protocols will be matched across projects for consistent results.

Producer case studies

Reporting dieback

Queensland

If you’re concerned about pasture dieback, please call the DAF Customer information centre on 13 25 23, or visit your local DAF office and talk to a DAF Beef extension officer.

NSW

If you suspect symptoms of pasture dieback: