It was in 2012 that Yellow Canopy Syndrome (YCS) was first detected in several crops of cane in the Mulgrave Mill area, just north of Cairns, close to four years later the cause of the condition is still unknown.
Since that first detection YCS has become a widespread problem throughout the northern and central Queensland sugar industries and Sugar Research Australia (SRA) has continues to try and find an answer for the issue to this day.
YCS Development Officer for SRA Belinda Billing said the severity of the syndrome is inconsistent from block to block, region to region, and year to year.
“SRA’s research program into YCS has shown that the symptoms include a negative impact on photosynthesis, and also that sugar transport is affected,” Ms Billing said.
“It is thought that these symptoms result in reduced yield in the paddock and perhaps a tendency towards late accumulation of sugars,” she said.
She said the severity of the YCS symptoms in the crop determine the level of impact on the crop.
“There are many blocks with low levels of YCS where it is difficult to determine the penalty imposed by the condition.
“In other cases the YCS is very severe and yield reductions may be estimated at 30 per cent or higher. These severe cases are extremely concerning.”
In 2015 the regions that are being most severely hit by YCS are Proserpine, Mackay and the Herbert River.
The Burdekin region has also suffered from widespread YCS, although there appears to be fewer severely affected blocks than in the other three regions.
YCS prevalence is low in the northern areas around Mossman, Gordonvale, the Tablelands and Tully, but there has been some isolated cases of very severe YCS in these areas and other cases of medium and low level YCS.
The Plane Creek area also experienced YCS this season for the first time, although not at the same severity as Mackay or Proserpine.
SRA’s YCS program is continuing to search for answers with the continuation of a research project Solving Yellow Canopy Syndrome, led by researcher Davey Olsen.
The project is being regularly refined based on learnings and will include a range of new trials going forward.
The project has two components, one understanding and working to solve Yellow Canopy Syndrome (YCS) and another looking for management strategies to alleviate the impact on the sugarcane crop, or managing YCS.
Mr Olsen and his team have partnered with productivity services in Mackay (MAPS), the Herbert (HCPSL), Proserpine (SSP) and the Burdekin (BPS) to investigate potential management strategies and find answers to some questions raised by growers in each region.
A series of replicated regional trials will be set up and supported by staff from both SRA and these productivity boards.
“The management practices being investigated range from soil health (including compost, mill mud, silica and biology preparations), to insecticides, nitrogen management, tissue culture and irrigation scheduling,” Mr Olsen said.
These treatments have been decided on with input from productivity services staff, who have taken into consideration questions raised by growers, as well as input from SRA delegates.
Trials are currently being implemented on sites that have shown recent severe YCS.
Despite dealing with Yellow Canopy Syndrome (YCS) for at least his second consecutive year, Burdekin cane grower Cy Kovacich is hopeful he will have one of his better crops in 2015.
The dry, hot and sunny summer days in January and February that have been such a challenge for many cane growers in the industry have been an opportunity for Burdekin farmers with irrigation and heavy soils such as those where Mr Kovacich farms near Clare.
For Mr Kovacich, the conditions created ideal growing conditions and meant there was no water logging to hold back crop potential.
Conditions he believes may have played a part in YCS not appearing to being as bad at his property this year compared to 2014.
“Last year we had a hot summer and squalls of rain and the YCS definitely accelerated in those conditions,” Mr Kovacich said.
“It was textbook examples of what we are hearing from SRA research that YCS can accelerate after rain events,” he said.
“While it was obvious visually that the crop was unwell and that it developed a significant wilt, it was difficult to gauge the final impact on yield.”
He said that the symptoms presented more severely in Q247A and KQ228A varieties, but that it still presented less severe symptoms across all other varieties at his farm.
Mr Kovacich’s advice to other growers regarding YCS focuses on the importance of minimising stress.
“Maintain a healthy crop.
“Don’t cut back on anything.
“And when they find a cure for it, if it is curable, we will deal with it then.”
