Is there a formula to reach 300-bushel corn?

The math adds up: Greg Stewart retools your understanding of how to drive corn yield.

It’s no secret, achieving high yielding corn is a complex process that requires multiple decisions at critical points throughout the growing season.

The good news is that Greg Stewart with Syngenta Canada can put you in the driver’s seat to unlocking corn yield potential by breaking down the key components that contribute to yield.

He believes that crunching the right numbers and leveraging powerful crop protection tools can support profitable decision making.

According to Stewart, understanding where corn yield comes from is the first step to reaching 300 bu/ac.

His approach, 4 Yield Drive, combines information growers may already have — like ear count, rows around the cob, ear length and kernel mass — with high performing corn crop solutions to improve corn yields.

“Higher, more profitable corn yields are a reality,” he says. “And using this approach, we can help growers start looking at their numbers and asking the key questions to improve their corn program.”

Where does corn yield come from?

The first step to reaching higher yielding corn is to understand the components, or gears, that contribute to yield.

“It sounds overly simple, but we haven’t often talked about corn productivity in these terms. So first ask yourself: what is your seed drop to plant stand conversion?” With this information, you’re on your way to understanding the first gear in your corn yield components.

Stewart notes that the corn yield equation is based on ears per acre, but to get the full impact of that number on your operation, you need to verify actual seed drop, then measure early season plant stand count, and finally follow up with a final harvestable ear count.

Here’s an easy yield estimate calculation for 300 bu/ac corn:

What components contribute to corn yield?

“When we talk about shifting yield into 4 Yield Drive, we refer to these four yield components as gears that can help us gain traction,” explains Stewart.

Strong, vigorous plants produce more ears in the field. This provides growers with the opportunity for more bushels per acre.

Rows around each cob are determined or set by V5-V7 growth stages. While plant genetics primarily drive number of rows around the cob, significant stress can impact this number. Examples of stressors (abiotic and biotic) include cold nights, starter fertilizer burn, poor weed control, and low nitrogen supply.

Ear length potential is determined starting at V5-V7, through to V15 growth stage. The kernels maintained in each ear is largely determined by plant growing conditions experienced in the window 10 days prior to silk emergence (R1) until 10 days after silk emergence. Stressors that impact ear length are dominated by drought, heat, and nutrient availability.

Stewart believes the ability to shift corn yield into high gear may depend more on kernel mass than any other factor.

Modern hybrid yield improvements are being driven primarily by more massive kernels. It is thought that two thirds of the genetic improvement in yield in the last 50 years can be attributed to kernel mass and one third to kernel number.

Tools to help drive corn yields

“Now that growers understand where yield comes from, the next step is to harness tools and products to take yield to the next level, and Syngenta is here to help,” says Stewart.

What about weed control?

“We know that full season weed control will help growers achieve maximum yield, but do weeds impact the rows around the cob and ear length?” asks Stewart.

The answer is yes.

Stewart explains that because weeds are opportunistic and compete for resources, they inhibit a crop’s ability to achieve its best yield potential.

Even small weeds can impact yield because they rely on and compete for the same resources as corn – space, light, water and nutrients.

That’s why managing early weed pressure will set the crop up for increased bushels per acre by promoting early-season plant vigour.

4 Yield Drive tool tip: Syngenta Foundation Acre^® portfolio of herbicide products are aimed at reducing the impact of weeds, weed populations and providing flexible, full season weed control.

Finish on top

Achieving record yields also requires keeping plants healthy, and that includes making in-season management decisions to keep crops disease free and productive. And supporting corn right through to grain fill is essential, because heavier kernels mean more bushels.

4 Yield Drive tool tip: Mitigate disease and maintain plant health with Miravis^® Neo fungicide. This proven crop protection tool has a long track record of being a great corn fungicide to protect crop quality and yield.

Miravis^® Neo provides a full spectrum of improvements to the corn crop, such as:

• Leaf diseases, including northern corn leaf blight, tar spot, and rust
• Improved kernel mass and grain quality
• Drought tolerance
• Plant standability and crop harvestability
• Feed quality
• ROI

Miravis^® Neo is proven to deliver in all growing conditions, especially the variations seen in Ontario over the last few years, contributing to yield achievement.

4 Yield Drive tool tip: YieldON™ liquid foliar biostimulant has the potential to increase yield by improving the flow of nutrients and sugars throughout the plant and is easily added to a planned Miravis^® Neo fungicide application.

The unique combination of naturally-derived ingredients improves the movement of nutrients and sugars from the leaves to the kernels during the grain-filling period, thus improving kernel mass and driving yields higher. Explore the Ontario trial results.

4 Yield Drive tool tip: When applied ahead of weather-related stress events, like drought, heat, low temperature, and physical damage, Megafol™ liquid foliar biostimulant helps your crops spend less time recovering and more time growing.

Check out the 4 Yield Drive lineup from Syngenta

4 Yield Drive for your high yielding corn

For growers wanting to improve their corn yields, knowing your starting point is critical.

4 Yield Drive invites growers and agronomists to capture the four key elements of corn yield in order to identify where weaknesses may exist and what can be done to push yield to the next level.

For more information on 4 Yield Drive, visit https://hey.syngenta.ca/row-crop/corn/ or talk to your Syngenta rep.

Performance evaluations are based on internal trials, field observations and/or public information. Data from multiple locations and years should be consulted whenever possible. Individual results may vary depending on local growing, soil, and weather conditions.

Always read and follow label directions. Miravis^® Neo refers to Miravis^® Neo 300SE fungicide. Acuron®, Foundation Acre^®, Halex^® GT, Miravis^®, Primextra^® II Magnum^® and the Syngenta logo are trademarks of a Syngenta Group Company. Magafol™ and YieldON™ are trademarks of VALAGRO S.p.A., a Syngenta Group Company. All other trademarks are the property of their respective owner. © 2025 Syngenta.