The Fieldman’s Files – Clubroot update ……continued from last week

Normand Boulet and Sheila Kaus
Agricultural Fieldmen for M.D. of Smoky River and Big Lakes County

Understanding Resistance and Resistance Stewardship: Spore load in the soil – can build very quickly with short rotations, by not using Clubroot resistant varieties and through poor volunteer and mustard family weed control, pathotype diversity in Clubroot populations – there are many different pathotypes, even a single root gall can have several different pathotypes, some are more virulent than others and not all are controlled by current Clubroot resistant varieties, by growing Clubroot resistant varieties in short rotation a person selects for pathotypes which are not controlled, they multiply rapidly and can become the prevalent pathotype within three years – meaning current Clubroot resistant varieties no longer work and canola can no longer be grown

Gregory Sekulic spoke next showing pictures of early onset Clubroot, very small almost unnoticeable galls caused by low level infections.

It is key for growers to be looking now, to identify fields with Clubroot early while management of it is still possible. Gregory spoke about the experiences in areas Clubroot is now rampant (mostly around Edmonton) showing pictures of how effective Clubroot resistant varieties are while warning that this tool must be used as one part of a suite of management efforts including longer rotations, volunteer and brassica family weed control and cleaning equipment.

Clubroot is found about 90 per cent of the time at field entrances, indicating the farmer has introduced it to the field on his own equipment.

You come to the field with the drill or combine, turn right and drop a bunch of soil and spores into your field.” Gregory highlighted the Clubroot disease cycle, explaining how spore buildup occurs, and can build very rapidly.

Norm Boulet spoke last, outlining the Agricultural Pests Act and Regulations, to which Clubroot was added in 2007.

The municipality must appoint inspectors and take active measures to deal with pests. Landowners and occupants must take steps to prevent introducing pests, and destroy pests on their land.

Norm also spoke about the Alberta Clubroot Management Plan, a great guideline outlining management efforts all producers should be aware of. Lastly Norm spoke about Municipal Policies and Procedures.

Because the Pests Act is very broad, requiring municipalities to take “active measures”, municipalities have adopted Policies which outline what they will do if Clubroot is found, including requiring longer rotations, anywhere from three to five years out of canola depending on the municipality, requiring the use of Clubroot resistant varieties when canola is grown, advising neighboring landowners due to the potential spread and so they can be aware and looking.

Overall, it was a whirlwind two-hour information session which explained how serious this disease is for our entire agriculture industry.

Preventing introduction to your farm is ideal so producers need to consider that anything which introduces soil, can introduce Clubroot.

The more soil being carried (agricultural & oilfield equipment) the more spores can be introduced leading to a greater initial number to start building from.

Reducing tillage reduces exposed soil, lessening the chances for erosion by wind and water and reduces the equipment needing to be cleaned. ATVs, wildlife and even foot traffic are possible sources but as the amount of soil being transported lessens, so does the chance of introducing spores.

Managing means scouting to detect the disease early.

Plants should be pulled at field entrances and random areas in the field, especially those where plants appear to have died prematurely or just didn’t grow as well as expected without any other obvious reasons.

Harvest time (after swathing or combining) is a good time to scout.

Dig up plants and examine roots for galls or swellings or bumps.

Early detection and rapid response makes this disease much more manageable.

The Canola Council of Canada has an excellent suite of videos on YouTube, explaining the disease cycle, proper scouting and testing for the disease.

If you have a chance, take the time to watch a few.

Municipalities have begun their yearly scouting programs for Clubroot and Virulent Blackleg.

The goal of these surveys is to find the diseases so they can be better managed by producers and municipalities.

We ask for your cooperation with our surveys so we can better serve everyone and help slow the spread of Clubroot within the Peace Region.

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