b'Clubroot that can overcome first generation CR was firstto use or avoid. Also, its going to help our industry better discovered in Alberta in 2013. To date, 36 different clubrootunderstand where different pathotypes occur, and if we are pathotypes have been identified, 19 of which are able toseeing new ones in Alberta, explains Barnes.overcome first-generation resistance. In 2017 and 2018 alone,While managing clubroot is entirely achievable through nine new pathotypes of the disease were isolated in theintegrated management practices, two challenges make this Canadian prairies. As of 2018, clubroot was confirmed to havedisease more problematic than other common plant pathogens.evaded resistance in 194 fields in Alberta. First, clubroot symptoms are typically below ground. While results from samples collected in 2019 and 2020 haventScouting requires time-consuming pulling up of plants, right at yet been released, the trajectory is clearfarmers shouldfarmers busiest time of year.expect the disease to continue producing additional resistance- We assume the numbers are much higher than the reporting breaking pathotypes. How big a concern is this? shows because many cases arent identified until the symptoms Its definitely worrisome, explains Hennig. Were wonderingget really bad, says Hennig.if genetics and breeding can keep up since we know how longTracking clubroots spread is also difficult for an entirely it takes to bring a cultivar to market. Farmers dont need to bedifferent reason: producers reluctance to admit to it.scared but they should be proactive and mindful of the disease. There is still a negative stigma around clubroot that prevents Seed companies spend millions of dollars and multiple yearsfarmers from talking about it, unfortunately, says Hennig. If I breeding for resistance. Understandably, theyre protectivecan communicate any message, its for people to be a bit more about the genetics that provide that resistance. First-generationopen about it. Lots of farmers now have it. I realize this can resistance was the first resistance unveiled and is effectivebe challenging with varying restrictions based on counties/against the most common clubroot pathotypes. MDs, but if you can talk about it, we can work together to help First generation CR cultivars are resistant to the sameyou figure out ways to manage it properly. Let your neighbours pathotypes and assumed to be derived from the Europeanknow. Let your retailer/agronomist know. Clubroot can be a winter rapeseed cultivar named Mendel says Hennig. Secondvery manageable disease.Madeleine Baerggeneration resistance is a lot more complicated: it has the same resistance profile as first generation, plus something else. So-called second generation CR hybrids could have the same or different clubroot resistant sources as each other. All producers should start managing clubroot by growing a hybrid with first-generation resistance.Sometimes growers get hung up on the newer product being better. Second-generation isnt necessarily better. So-called first-generation CR is resistant to the main pathotypes of clubroot and is a good starting point for all farmers. If you see clubroot appearing in first-generation CR, lengthen your crop rotation and switch to a second-generation, says Barnes.Finding a low level of clubroot in a resistant canola crop doesnt necessarily mean that the specific disease pathotypesIS FUSARIUM STARINGpresent in your field have overcome your canola hybrids geneticYOU IN THE FACE? resistance. In order to be registered as resistant, a canola hybrid has to prove an infection rating of 30 per cent or lessboth in terms of the number of plants affected and the severity of theYOU WILL NEVER KNOW UNLESS YOU GET YOURdisease infection on each plantcompared to a non-resistantSEED TESTED BY AN ACCREDITED SEED LABhybrid.CR varieties are not always 100 per cent resistant. In some cases, the pathotype hasnt broken resistance: the infectionSURVEILLANCE IS VITAL FORwould count as an allowable amount, says Hennig. DISEASE MANAGEMENTThe Clubroot StruggleStill, its always better to be safe than sorry. If clubroot appearsCONTACT YOUR LOCAL SEED on a CR cultivar in your field, its always a good idea to send aCLEANING PLANT TO SUBMIT YOUR SEED SAMPLES TO AN Ziplock bag of galls away to the U of A for pathotyping. ACCREDITED SEED LABPathotyping may help farmers understand which hybrids WWW.SEEDPROCESSORS.CA/SEED-SMARTFall 2021 51'