Pasture dieback confirmed on NSW North Coast

According to the NSW Department of Primary Industries:

Pasture dieback is a condition killing large areas of sown and native summer growing pasture in Queensland. The size of areas affected varies. It starts as small patches and can spread to affect large areas. In some cases whole farms have been affected. It is not limited by landscape or soil type. Livestock avoid grazing these areas making them unproductive. 

Pasture dieback was first identified in Central Queensland and has now spread from Far North Queensland to the NSW border. Suspected pasture dieback was reported on a property in northern NSW in autumn 2019.

Figure 1: Small patch of dieback affected pasture. Photo: S J Baker

Sown species known to be affected include:

• Buffel grass (Cenchrus ciliaris)
• Digit grass (Digitaria eriantha)
• Rhodes grass (Chloris gayana)
• Green and Gatton panic (Megathyrsus maximus)
• Bambatsi panic (Panicum coloratum)
• Kikuyu (Pennisetum clandestinum)
• Paspalum (Paspalum dilatatum and P. plicatulum)
• Creeping bluegrass (Bothriochloa insculpta)
• Sabi grass (Urochloa mosambicensis)
• Signal grass (Brachiaria decumbens syn. Urochloa decumbens)
• Para grass (Brachiaria mutica syn. Urochloa mutica)
• Setaria (Setaria sphacelata)
• Purple pigeon grass (Setaria incrassata)
• Forest bluegrass (Bothriochloa bladhii ssp. glabra)
• Indian couch (Bothriochloa pertusa)

Other species known to be affected include:

• Black spear-grass (Heteropogon contortus)
• Forest bluegrass (Bothriochloa bladhii)
• Golden beard grass (Chrysopogon fallax)
• Giant rat’s tail grass (Sporobolus pyramidalis)

There are potentially more grass species that could be affected.

On 9 April 2010 The Daily Examiner and The Northern Star reported:

The first NSW case of pasture dieback, which kills sown and native summer growing grasses, has been identified on the state’s North Coast.

Producers should contact NSW Department of Primary Industries or the Exotic Plant Pest hotline, 1800 084 881 if they suspect their pasture has the condition.

NSW DPI Pasture Systems development officer, Sarah Baker, said it’s important to identify where pasture dieback is occurring to determine its spread and impact.......

“Pasture dieback causes summer growing grasses to turn yellow and red, become unthrifty and eventually die.

“Cases of suspected pasture dieback were reported during the 2018-19 summer, but with drought masking the condition, confirmation was impossible at the time.

“Recent rainfall has assisted us in identifying dieback, which previously had been found only in Queensland.” It has been estimated the affected area in Queensland is at least 200,000 hectares and could cover up to 4.4 million hectares, with the cause still to be confirmed.

The size of areas affected varies. It starts as small patches and can spread to affect large areas.

In some cases whole farms have been affected.

While control options remain dependant on identification of the cause, producers can continue to maintain production with broadleaf species, including legumes and brassicas, which are not affected by dieback. Re-sowing perennial grasses into dieback affected areas is not recommended. However, annual winter growing forages, including oats and dual-purpose cereals can help fill winter feed requirements.

NSW DPI is working with the Queensland Department of Agriculture and Fisheries, University of Queensland, Queensland University of Technology and industry, through Meat & Livestock Australia, to explore the cause of the condition.

As researchers work to better understand pasture dieback, including investigations of insect involvement, NSW DPI is developing options for future management. More information is available from the NSW DPI website www.dpi.nsw.gov.au/agriculture/pastures-and-rangelands/establishment-mgmt/pests-and-diseases/pasture-dieback.