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Act Now: The Window for Curbing Weed Competition is Short

February 10, 2021
this agronomic image shows clean corn rows.

Early-season weed competition can be detrimental to corn. Aim for clean rows throughout the entire season.

Early-season weed management is crucial to a high-yielding corn crop. Weeds compete with crops for limited resources such as sunlight, nutrients and water, and the yield impact from this competition happens fast. Alarmingly, research has also demonstrated that even non-competitive early-season interactions between weeds and corn can significantly affect crop growth, development and yield potential.

The Point of No Return

Fast action is required as soon as weeds are spotted in a field, as there is a point – coined the “switch-point” by Canadian researchers – where corn crops are irreversibly damaged from this early-season competition and won’t regain their full yield potential. Once corn passes this switch-point, its growth has been fundamentally altered by competition. Corn stalks will divert nutrients necessary for strong root development, instead growing taller and producing wider leaves to compete for light.

While this extra growth may appear to be a good thing, in reality the corn plant is overdeveloping its above-ground portion at the expense of good root growth. A smaller root system will struggle to support the plant and will be more severely impacted by unfavorable growing conditions, such as water stress. This leaves the plant vulnerable, negatively impacting yield and creating a situation that can’t be overcome with post-emergence weed management.

Stay Ahead of Costly Weeds

The best way to prevent this situation is to start with a clean field and to keep it that way. 2 products that we recommend to help are Gramoxone® SL 3.0 and Acuron® herbicides. A burndown application of Gramoxone SL 3.0 shows fast-acting results in as little as 48 hours, delivering convenient, flexible and dependable burndown of emerged grass and broadleaf weeds.

With 4 active ingredients, including the Syngenta-exclusive bicycloprone, Acuron provides season-long weed management of more than 70 broadleaf and grass weeds to help fully protect corn’s yield potential. And because of its unique combination of powerful weed management, longest-lasting residual and proven crop safety, Acuron lets growers discover 5-15 more bushels an acre than any other herbicide when applied preemergence and at full label rates.*

The negative impact of early-season weed competition can last all the way through harvest, but with timely early-season herbicide applications, growers can achieve clean fields, avoid the “switch-point” and help corn crops reach their full yield potential.

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* When applied preemergence and at full label rates. Acuron yield advantage range based on 2016 Syngenta and University trials comparing Acuron to Corvus®, Resicore®, SureStart® II and Verdict®. For more information on Acuron versus an individual product, ask your Syngenta representative.