Canola School: Top tips when soil testing for clubroot

Episodes:

Spring, summer, or fall — when do you think is the best time to test for clubroot?

Visual symptoms on the plant show up later in the season, yes, but that’s not when soil spore load is highest, explains Kim Kenward of  20/20 Seed Labs, in this episode of the Canola School.

“Soil testing is the best way to track where (clubroot) is going to show up once it’s outside the plant,” she says.

That said, the best time to soil test is once you no longer have a growing crop. That’s because you need the plant to decay and release the spores into the soil. In the spring, you’ll get the spores germinating and looking for a new host, and that lowers the spore load, she says. Fall is likely the best time to look at the total risk picture, when it comes to a soil test.

Where should you soil sample if clubroot detection is the goal? If you’ve pulled plants and found symptoms, go ahead and mark that area and come back to it. As a general rule, though, high traffic areas, such as approaches and field entrances, are the most likely areas to find spores early on.

Kenward adds that mixing cores can dilute a sample too much, so aim to run as many samples as you can reasonably afford (or keep composites to a specific site).

In the absence of a host, spore loads drop quickly in the first two years, she says, but spores can persist 10 to 20 years. And just a few spores can spread the disease if there is a susceptible host present.

Leave a Reply

 

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Privacy Preference Center

Necessary

Necessary cookies help make a website usable by enabling basic functions like page navigation and access to secure areas of the website. The website cannot function properly without these cookies.

gdpr, __cfduid, PHPSESSID, wordpress_test_cookie, woocommerce_items_in_cart, woocommerce_cart_hash, wp_woocommerce_session, wordpress_logged_in, wordpress_sec, wp-settings, wp-settings-time, __cf_mob_redir, wordpress_cache
__cfduid

Marketing

Measuring interactions with the ads on the domain.

__gads,fsk_ut_2317
scmtid,v,a,JSESSIONID
IDE

Statistics

These are used to track user interaction and detect potential problems. These help us improve our services by providing analytical data on how users use this site.

_ga,_gid,_gat,_cb,_chartbeat2,_chartbeat4
_ga,_gat
_ga,_gid
metrics_token

Preferences

Preference cookies enable the website to remember information that changes the way the website behaves or looks, like your preferred language or the region that you are in.

chartdefaults, comment_author, comment_author_email, comment_author_url
JSESSIONID, _os_session,anonymous_votes,csrf-param,csrf-token,user,user-id,user-platform,intercom-session,intercom-lou,intercom-session
personalization_id, tfw_exp