Key Points
- Objective: This study evaluates how corn leaf orientation (perpendicular vs. parallel to the row) impacts yield.
- The Significance: Correct leaf orientation offers benefits of increased light interception, less sunlight to encourage weed suppression, cooler in-canopy temperatures, and moisture preservation.
- Key Results: From 2018-2024 at the PTI Farm in Pontiac, IL, 25-30% of plants showed incorrect (parallel) leaf orientation, resulting in yield losses of 7.3% to 11.2%, or roughly 18.0-23.0 Bu/A per plant.
- Agronomic Implications: Early data suggests adjusting embryo placement may reduce incorrect orientation. Additionally, narrow-row corn shows the highest rates of incorrect orientation in our studies thus far.
What is leaf orientation?
The next time you’re out scouting your cornfield, it might be a good time to think about architecture.
Leaf architecture, that is.
In corn cultivation, a primary component of leaf architecture is leaf orientation, or the direction the leaves canopy in relation to the row.
- Correct orientation positions the leaves perpendicular to the row (i.e., if your rows are North-South, the leaves face East-West).
- Incorrect orientation positions the leaves parallel to the row (i.e., if your rows are North-South, the leaves face North-South).
Why is leaf orientation important?
Corn leaf orientation impacts a number of vital factors on your field. Correctly oriented leaves canopy over the soil between rows, resulting in:
- Cooler in-canopy soil temperature
- Increased soil moisture preservation
- Increased light interception
- Improved weed suppression
Leaf Orientation Study Results
Does leaf orientation actually affect total yield? As it turns out, it does.
At the PTI Farm, we studied the impact of corn leaf orientation from 2018-2024 and found some pretty eye-opening results:
- Incorrect leaf orientation occurred around 25-30% of the time.
- Total yield loss as a result of incorrect orientation ranged from 7.3% to 11.2%.
- Average yield loss per plant with incorrect orientation ranged from -18.6 to -23.3 Bu/A.
Here’s a simple example to put it into perspective: If you had a corn yield of 200 Bu/A, a 10% loss would mean a 20 bushel yield loss—simply due to incorrect leaf orientation!
We’re continuing to research this challenge to determine the best agronomic solution. Some research has indicated that embryo directional placement may improve leaf orientation. We’ve also noticed that narrow-row corn has resulted in the highest number of misoriented plants.
So the next time you walk your field, take a look at your leaf orientation. (Once you see it, you won’t be able to unsee it—trust us.) We look forward to bringing you more on this topic as this study continues!
In-Depth Study Videos
InsidePTI
S4•E11
InsidePTI
S1•E20
