Corn School: Getting to the root of field variability


Corn fields across Ontario are full of variable plant development and that should be a concern for growers, says University of Guelph crop researcher Dr. David Hooker.

Fields are littered with areas of yield-compromising backward and slow-to-develop plants. Hooker believes corn variability is even more apparent this year due to significant weather challenges; with cold planting conditions followed dry soil conditions and then drought, in-season and pre-existing agronomic issues have proved challenging for growing corn plants.

On this episode of RealAgriculture’s Corn School, Hooker gets to the root of corn plant variability.

One of the leading culprits is poor crop rotation, says Hooker who notes that many corn-after-corn fields are showing evidence of the detrimental effects of growing the crop continuously. Too much tillage, especially before planting, poor soil structure, and fertility issues, which become more yield-limiting in unfavourable weather conditions, also rank high on his list of causes. (Story continues after the video.)

Overall, plant and field variability does produce considerable yield loss, Hooker notes. His data looking at in-row variability shows that when one in every six corn plants are four leaves behind other plants, the field will see a 10 percent reduction in yield — that’s 20 bushels per acre across a 200 bu/ac field.

Variability also creates in-season management challenges when it comes to effectively applying fungicides and insecticides to control disease and insects.

Hooker says there’s not much that can be done to fix the problems for 2020, but he encourages growers to get out and investigate areas of variability. He believes most of the problems can be remedied with good, sound agronomic practices including better rotations, reducing tillage, soil sampling, and improving weed control and drainage.

Click here for more Corn School episodes.

Wake up with RealAg

Subscribe to our daily newsletters to keep you up-to-date with our latest coverage every morning.

Wake up with RealAg

Other Episodes

Corn School (view all)Season 9 (2020) Episode 10

Please register to read and comment.

Privacy Preference Center


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, realag


Measuring interactions with the ads on the domain.



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.



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


Register for a RealAgriculture account to manage your Shortcut menu instead of the default.