A DEVASTATING disease has caused Australia's largest ginger-growing company to look outside the traditional growing areas on Queensland's Sunshine Coast for suitable land to produce 'clean seed'.
Templeton Ginger is a third-generation family-owned business with strong ties to the the Buderim Ginger Factory on the Sunshine Coast. The family grows between 55 and 65 hectares of ginger each year on farms at Eumundi, Gympie, Kenilworth, Noosa and North Arm.
A recently developed quarantine farm at Glenorchy, south of Maryborough, is part of Templeton Ginger's strategy to avoid the devastation of pythium infestations that affected the Sunshine Coast crop in 2010 and 2011.
Pythium is a soil-borne disease that can spread alarmingly quickly under the right conditions. "Just a one-centimetre clod of infected soil can infect a whole farm," said farm manager Reuben Stonier.
"The organisms move like tadpoles through the soil at a rate of one to three metres a day, invading plant roots as they go."
Once pythium is in the soil there is no known treatment or control, though researchers from DAFF and the University of Queensland, as well as growers, are trying to find ways to bring infected farms back into production.
The disease causes the ginger roots and rhizomes (the edible part) to decompose, making ginger production impossible.
"At the moment, the only solution is to move to a new, disease-free block and to ensure that only clean machinery and clean planting material are used," said Mr Stonier.
The 8ha block at Glenorchy was planted in spring last year and is supplying disease-free 'seed' for planting on the other Templeton farms in October.
Mr Stonier said this year was a test for the farm and the Maryborough climate.
"The soil on this farm is not ideal but we are working to build up the organic matter and increase the pH," he said. "We expect that the farm will be able to produce sufficient good quality seed to supply the other farms."
Clean seed is also important in managing other diseases of ginger including fusarium, big bud, nematodes, Erwinia and phytophthora.
The Templetons grow two varieties - Queensland for processing into jams and confectionery lines and Jumbo for the fresh produce market.
"The Queensland variety has a flavour and size profile that makes it more suitable for processing," said Mr Stonier.
"The fresh produce varies in the supermarket from 'new season', which is milder and doesn't need peeling, to more mature bulbs that need to be peeled but have a stronger flavour."
Ginger is a very intensive crop and blocks need a five-year break between crops. As a result ginger is expensive to produce. An 8ha production unit requires access to at least 40ha of land to allow for the long fallow. Successful production also needs soils with high organic matter and a pH around 6.
"It takes five years after a ginger crop to build up the soil organic matter and fertility before another ginger crop can be planted," said Mr Stonier. "We usually use forage sorghum and soybeans as green manure crops and apply high rates of fowl manure and compost to the soil beween crops."
Mr Stonier is also developing his skills as a cane grower, starting with a 4ha block with several different varieties this year to supply plants for next season. "Cane should work well as part of the rotation with ginger," he said. "We plan to grow around 24 hectares to make use of our fallow land, help with weed control and add organic matter through the return of the green cane trash blanket."
One problem on the farm is toxic levels of manganese in the soil but increasing soil organic matter will help bind excess manganese. "We are also needing to adjust our growing system to suit the warmer and drier climate at Glenorchy compared to the farms on the Sunshine Coast."
While planting is mechanical, harvesting and weed control are manual operations. The Templetons' total planted area of 57 ha employs 70 staff year round, with additional workers to assist with peak harvesting.
Fijian ginger imports
Almost 10 years ago Fijian authorities first formally requested market access for fresh ginger into Australia.
Australia's DAFF Biosecurity assessed the proposal and determined that trade can go ahead, provided the exports follow certain biosecurity protocols.
Dried ginger and ginger for processing have not been restricted but if the import permit is issued, Fiji will be the first country to import fresh ginger for human consumption into Australia.
Fiji ginger weevil, yam scale and several nematodes were identified as biosecurity risks that Fijian exporters must manage. Two ant species have also been identified as potential contaminants of fresh ginger consignments from Fiji. Fiji already exports ginger to the USA, New Zealand and Europe without further treatments.
The Australian Ginger Industry Association and Queensland Agriculture, Fisheries and Forestry Minister John McVeigh have raised concerns over the potential for soil-borne diseases to be introduced in imported ginger rhizomes.
The federal government's risk assessment indicates this is a low risk because the imported ginger is for immediate consumption and that very little of the imported product is likely to be planted by home gardeners.
