Manitoba canola growers aren’t facing the full mischievousness of clubroot — yet.
The soil-borne disease is a major issue for farmers in other locales, where it limits cropping options, stunts plants and hampers yield.
Provincial specialists say they hope it remains a mild problem here, and scouting and diligent crop rotation will be the key to ensuring it.
“Clubroot is present in most Manitoba RMs at low levels,” said Pratisara Bajracharya, field crop pathologist with Manitoba Agriculture, Food and Rural Development (MAFRD). “Between 2009 and 2015, 1,204 fields were tested and there were 159 positive results with eight fields showing symptoms.”
Bajracharya spoke on the presence and prevention of clubroot at the Dauphin Agriculture Society’s Farm Outlook 2016 held on March 10.
“At this point, Manitoba is only seeing mild infestations, compared to Alberta where we have seen some intense clubroot cases, specifically in the Edmonton region,” said Bajracharya.
Clubroot is a soil-borne disease, and specialists say, once it is present in the soil, there is no getting rid of it.
“Once you find clubroot in a field it is nearly impossible to eradicate,” said Justine Cornelson, agronomy specialist with the Canola Council of Canada, who also spoke at the Dauphin event.
Cornelson insists soil tests are essential in order to effectively manage infested fields and prevent increasing the disease’s severity like our western neighbours have seen.
“Clubroot is easily transferred through soil movement by wind, water erosion, on-farm machinery and vehicle tires, so in order to effectively limit transfer, we first need to know where it is present,” said Cornelson.
Cornelson suggests using the services of the Manitoba Pest Lab in Winnipeg, which offers affordable testing options (www.mbpes tlab.ca).
Other than a soil test, actively scouting canola fields throughout the growing season is the best way to identify the presence of the disease.
“I can not stress how important it is to be scouting and watching for irregularities in the field,” said Bajracharya. “Clubroot will cause canola to ripen prematurely and eventually cause death so watch for stunting, withering, premature ripening, and if you suspect irregularities, pull up plants and look for galls.”
Cornelson recommends paying particular attention to field entrances and drainage areas, as these tend to be where symptoms commonly appear.
Coping with clubroot
For those who may have clubroot present in their fields, Bajracharya reassures it does not mean the complete shutdown of canola production.
“Having clubroot present does not mean that you can’t grow canola, it just needs to be properly managed,” she said. “Clubroot cannot survive without the host and so implementing some extended rotations will aid in killing bacteria spores.”
Both Cornelson and Bajracharya recommend a one-in-four rotation and sticking to clubroot-resistant varieties for added protection.
“Even if you don’t currently have clubroot symptoms, if you are in a high-risk area I would highly recommend using a resistant variety. Also, I would recommend direct seeding and reducing tillage as much as possible,” said Cornelson. “Tillage can increase the risk of transferring the infestation by way of increased soil erosion.”
Sanitizing equipment and vehicles that have been active in clubroot-present fields is also vital in reducing transfer.
“We all need to be practising best management practices when it comes to sanitation of equipment. I would also warn of being wary when you are purchasing used equipment, and know who all has access to your land and ensure they are being just as diligent,” said Bajracharya.