The number of smut-hit cane farms under quarantine in Australia's eastern sugar-producing areas has grown to 31, but all are still concentrated in one area, a spokeswoman for the Canegrowers organisation said on Thursday.
This is up from 21 on June 27, after the first discovery of the highly contagious fungal disease in mid-June, the spokeswoman for Australia's main sugarcane growers group said.
"They're concentrated around the Children hotspot, with a few in the Bundaberg area as well," the spokeswoman said. Bundaberg is about 50 kms (30 miles) east of Children, where the first outbreak was discovered, around 250 kms north of Brisbane.
Australia is battling the first finding of smut in its main eastern cane fields. The country is normally the third-largest cane sugar exporter in the world, after Brazil and Thailand.
Australia's sugarcane is grown along 2,000 kms of the tropical Queensland coast and fears were initially high that the disease would quickly spread throughout the entire industry.
Surveillance in Marlborough, about 75 kms south of Bundaberg, had produced no findings of smut, the spokeswoman said.
Smut devastates cane crops and sends production yields plummeting by between 30 percent and 100 percent. It is easily spread by wind dispersing fine black powdery spores, and can also be spread by human contact and by machinery.
The disease typically has a limited effect on production in its first year, before it begins to affect output from year two by stunting plants and impeding re-growth.
The Canegrowers spokeswoman said harvesting of cane in areas hit by smut was well underway, under strict guidelines.
Harvesting, crushing and processing of sugarcane affected by smut poses no human health threat as the cane goes through the milling process to produce raw sugar.
Crushing of harvested cane is also underway in northern areas around Cairns and Townsville, as well as in central Queensland and through southern parts of the state.
The last seven of Queensland's 24 operating sugar mills should start in the next few weeks, the spokeswoman said.
The Australian Bureau of Agricultural and Resource Economics last week forecast that Australia's production of raw sugar would fall to 4.8 million tonnes in 2006/07 from 5.1 million tonnes last season because of cyclone damage this year.