Some Manitoba fields are infected with clubroot, a serious canola disease, but how many and where?
To find out one soil sample is being collected from each of the province’s 900 or so agro-townships, Anastasia Kubinec, Manitoba Agriculture, Food and Rural Development’s (MAFRD) oilseed specialist, said in an interview April 23.
While the location of infected fields and their owners will remain confidential, a map, probably by rural municipality (RM), will show where the disease has been found. It will be released this fall or next spring.
“We want to give farmers a sense of where it (clubroot) is and how bad it is and the precautions they should be taking with an RM that has high levels versus an RM that has been tested and has zero,” she said.
“If they are positive the farmer will be given information to contact either myself or Holly (Derksen, a MAFRD plant pathologist) to discuss next steps.”
Farmers can volunteer their land for sampling and get the sampling and the confidential test results for free. Interested farmers can call their local MAFRD GO office or email [email protected]
Only volunteers in areas so far untested will be eligible. Most of those areas are in the northwest, including around Roblin, Swan River and The Pas.
The test, which can measure very small levels of the microscopic, soil-borne plant pathogen called Plasmodiophora brassicae, normally costs $125. However, it can be cut to $25 if farmers participate in a program under Growing Forward 2 and qualify for funding from the Manitoba Canola Growers Association, Kubinec said.
Since clubroot is soil-borne, the disease can spread with soil, carried on equipment, on crops or moved by wind or water.
Farmers should look for the disease at field entrances and along waterways.
Ideally farmers should clean their equipment between fields and make sure others entering their land do too.
Clubroot was first detected in Alberta canola in 2003 in Sturgeon County northwest of Edmonton. The pathogen classified as a Protist — a group of organisms with characteristics of plants, fungi and protozoans — has spread in Alberta and has also surfaced in Saskatchewan.
Manitoba has been testing for clubroot since 2009. The first case, in soil only without canola showing symptoms, was detected in 2011 and announced in 2012.
As of last year Manitoba had 13 confirmed cases of clubroot in 10 municipalities. Eleven of them were based on soil tests, with no visible symptoms in canola plants. In the two cases where plants were infected, the symptoms were minor. Updated information will be released next month, Kubinec said.
The hope is finding where clubroot is in Manitoba will help with controlling it, which is done through crop rotation, sanitation (biosecurity) and planting clubroot-resistant varieties when appropriate.
“I do have a feeling that we are going to see (from the survey) a heck of a lot more clubroot than we thought, but it could be all at very, very low levels,” Kubinec said.
“Ninety-nine per cent of the time when we pick it up in the soil (to date) we have never seen any symptoms in the field.”
That means clubroot could become a problem in some fields if farmers grow canola every year for say five years. But conversely with a one-in-four-year rotation clubroot symptoms might not develop, Kubinec said.
European and local preliminary research shows clubroot has a half-life of four years. With 100,000 clubroot spores per gram of soil, symptoms can show up in canola.
“If you don’t grow canola for four years… it drops to 50,000 (spores per gram) so you’re not seeing symptoms. If you can wait another four years then you drop to 25,000 and that’s getting pretty low. So rotation is a huge component to managing the disease and also reducing the concentrations in the field so that you’re not building up levels to see symptoms.”
Funding for the clubroot survey comes from the Growing Actions program under the federal-provincial Growing Forward 2, program, Kubinec said.
Soil samples will be collected and tested by staff at the new Pest Surveillance Initiative (PSI) laboratory in Winnipeg. The lab is managed by the Manitoba Canola Growers Association, which is also helping fund it, along with the Manitoba and federal governments.