Knowing the leaf structure and ear flex characteristics of the corn hybrids you’ve purchased can help you decide where to place them in the field to maximize growth and performance this season.
If you don’t know that specific information about the hybrids you’ve selected, now’s the time to get with your seedsman or agronomist to help you figure that out, encourages Ken Ferrie, Farm Journal Field Agronomist.
Ferrie says there are four ear types: flex, semi-flex, semi-determinate or determinate.
Hybrids exhibit varying ear flex characteristics, including girth, length, and kernel/depth flex. Some hybrids may primarily flex in one of these traits, while others may show flexibility in all of them. This is an important consideration when managing hybrids throughout the growing season.
Click on the link “Understanding Ear Flex” for more information about ear flex.
Ferrie adds that there are also four leaf type structures in corn plants – hybrids have upright, semi-upright, semi-pendulum or pendulum leaves.
“Corn hybrids with more of a ‘floppy’ leaf type will maximize leaf area index at much lower populations than upright hybrids,” Ferrie says. “Semi-upright hybrids split the middle.”
Jared Bergan, research agronomist for Crop-Tech Consulting, Heyworth, Ill., adds: “One of the things you want to do is place your hybrids so they can capture 97% of the available sunlight.”
Bergan explains more about the roles of plant leaf structure and ear flex in corn performance in the brief video provided.
Ear Type And Leaf Structure Can Tag Team
Ferrie provides a few examples of intercepts between ear type and leaf structure:
For water-stressed fields, choose taller, pendulum-leaf hybrids that can flex ear size to make up for a lower plant population. The pendulum leaves ensure sunlight is intercepted before reaching the ground. Ferrie calls these defensive hybrids because you are managing a stressful management zone.
“When water consumption is a concern, lower the plant population to lower water usage,” he says. “Flex-ear hybrids can compensate for a lower ear count. Floppy leaf structure will maximize leaf area index at lower populations. Narrow row spacing reaches maximum leaf area index more quickly to harvest more water.”
Plant upright-leaf hybrids on your better, stress-free soil. These “offensive” hybrids require higher populations to capture 97% of sunlight.
“When lack of sunlight interception is a concern, use upright leaf structure to let sunlight deep into the canopy. Use a determinant ear hybrid to allow you to push populations to achieve maximum leaf area index and a higher ear count,” he says. “Narrow rows will capture more sunlight.”
“When fields have high amounts of variability going from surplus water to droughty soils, use semi-flex ear types and variable-rate planting to mitigate the risks. Use semi-upright leaf structure to maximize sunlight and drought protection. Also, narrow the rows to help with both.”
Plant recommended population ranges. “Our Farm Journal studies have proven pushing population after you reach 97% light capture stresses most hybrids, but especially those with a lot of flex in ear size, and may actually lower yield,” Ferrie says.
“After 97% light capture, increased yield comes not from more plants, but from practices such as fertility management and pest management.”
For more insights on leaf architecture, ear type and how the two relate, check out these additional articles on AgWeb:
Ken Ferrie Explains Flex and Fixed Corn Hybrids
Narrow Rows: Fixate on Structure and Population
