* A total of 500 Alberta fields now have clubroot disease
* Many fields ordered not to grow canola
* First clubroot resistant crop variety now available
WINNIPEG, Manitoba, Jan 14 (Reuters) - The most-feared disease affecting canola spread faster than expected in 2009, reducing the number of acres that can grow Canada’s No. 2 crop, an Alberta government official said on Thursday.
In total, roughly 500 Alberta fields are infested with clubroot, a disease that prevents the canola plant’s roots from taking in nutrients and water and can stay in the soil for up to 20 years. Local county governments have banned many of those fields from growing canola for between 3-6 years.
Officials confirmed 50 more fields with clubroot last year in the western province, which is slightly less than found in the past few years. But they had expected severe drought to all but halt the spread of the disease, said Murray Hartman, oilseed specialist for the Alberta government.
Drought stunted the growth of crops like canola and spread of clubroot early in the 2009 growing season, but July rains improved conditions for both, Hartman said.
“We were hoping the drought would keep it more in check than it did, so we were surprised,” he said.
The Alberta government records the number of fields by ownership and does not know how many acres have the disease, Hartman said. Earlier estimates have put the number of infested acres in the thousands.
Canada is the world’s top exporter of canola, which is crushed for its oil, to be used in cooking, and for its meal, which is added to livestock feed. Last year, farmers harvested 11.8 million tonnes, their second-largest crop ever and second only to wheat production.
Clubroot has ravaged European crops for centuries and was first detected in 2003 in Alberta, the main Canadian province affected by the crop disease. Last summer, researchers in the top crop-growing province of Saskatchewan found the pathogen that causes clubroot, but not the disease itself.
The first clubroot-resistant canola variety, sold by Dupont (DD.N)-owned Pioneer Hi-Bred, will be widely available for the first time this upcoming spring planting season, Hartman said.
Alberta has had a lot of snow this winter, which could mean wet spring conditions that would help clubroot spread further, Hartman said. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LINK: Map of clubroot contamination in Alberta here ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ (Reporting by Rod Nickel; Editing by Marguerita Choy)