New research and paddock trials are helping to provide local farmers with practical strategies to better manage pasture dieback.
Southern Cross University, in partnership with North Coast Local Land Services, is leading the work, which aims to determine which grass species are more tolerant to pasture dieback. Terry Rose from SCU and Nathan Jennings from LLS recently hosted field days at trial sites in Alstonville and Yorklea to share the latest findings with producers.
Options for farmers
“People are keen to find out what species they should plant, or if there are other management options available,” Terry said.
“We know that slashing, or keeping your biomass low, can help to delay the onset or spread of pasture dieback, but it won’t stop it. It is also not practical nor sustainable to keep pastures short indefinitely.
“We are observing Setaria and Signal Grass continuing to show good tolerance to pasture dieback. Brizantha is also looking good at our trial sites, although we haven’t seen how it might fit into a grazing system on a larger scale yet, in particular how well it will persist over a few years given our winters are much colder than where this species is typically grown.
“All tested Rhodes grass cultivars at the Alstonville trial site (Katambora, Callide and Endura) are only showing middle-of-the-range tolerance; that is, they are impacted by dieback and show symptoms, but won’t necessarily die off. Unfortunately, that includes the Endura variety, which has been widely promoted as being more tolerant to dieback than other Rhodes grass cultivars.”
At the Yorklea site, temperate grasses (Cocksfoot and Fescue) have been trialled, growing well in the small plots but struggling in the larger paddocks with grazing pressure from kangaroos and the recent recovery of the previously pasture dieback-affected Bluegrass outcompeting the temperate species.
Bluegrass has demonstrated recovery from pasture dieback at many sites. Nathan does caution however about the longer-term risk of pasture dieback returning in highly susceptible species such as bluegrass. It is impossible to say if susceptible species will be hit every year, but equally it does not mean that they are never going to see it again. Observations from across the district show that species such as creeping bluegrass and kikuyu have seen pastures recover from the soil seed bank only top be hit again in the following year. For some producers, this creates an unreliable feedbase.
Some producers at the workshops are reporting 20-50% reduction in their stocking rate due to pasture dieback. Whilst there has been some recovery of the tropical pasture base this past season, many producers remain impacted particularly with the spread of woody and broadleaf weeds into the bare areas of pasture.
Based on experience further north, Nathan believes pasture dieback will affect more producers, especially with highly susceptible species such as paspalum, creeping bluegrass and kikuyu, and they will need to make some decisions about transitioning to a more tolerant pasture base like Setaria and/or Signal Grass for longer term resilience in the feed base. “Resowing a new pasture base is not straightforward, nor cheap” explained Nathan. “But I think producers need to weigh up the risk of doing nothing and continuously battling weeds with an unreliable feedbase against slowly establishing a more tolerant pasture base on their farm.”
Tim and Anna Gilliland at Doon Doon have been making the transition to Setaria and Signal Grass as a pasture base after the loss of large areas of kikuyu pasture over the last few years. You can read more about their experience here.
LLS have developed a ProPastures course that includes pasture establishment and transition, to help producers reduce the risk and cost of this. Contact LLS directly for more information if you’re interested admin.northcoast@lls.nsw.gov.au
Late onset of dieback
It has been a late season for pasture dieback on the Northern Rivers, with symptoms only showing at SCU’s Alstonville trial site in late May and early June. Terry said they were still spotting mealybugs last week – normally it’s usually too cold for them at this time of year.
“We are seeing more and more paddocks in our region affected by dieback, and it’s spreading down in the Hunter Valley as well, which is concerning,” he said.
“America is also facing some major challenges with pasture dieback at the moment – in Texas, more than 20 counties are reporting damage to pastures, and these are important agricultural regions.
“Hopefully through our research, we can get some more answers and help farmers stay productive.”
Find out more
Visit our pasture dieback section for more information, and stay tuned to the Farming Together Facebook page for future field walks.
This project is supported by the Meat & Livestock Association, Local Land Services, and Southern Cross University. Additional support is provided by the Lismore Node team of the SQNNSW Hub.