If you’re targeting maximum corn yield, you need to fine-tune plant nutrition for a particular two-week period of the corn growing season, says Tony Vyn, professor of agronomy at Purdue University.
That’s because while we’ve been focused on more rows and kernels per row per ear, modern hybrids can pack tonnes of yield in if the focus shifts from kernel number to kernel size. And, if we plan ahead, we might be able to get that yield with the same amount of nitrogen, Vyn says.
The lag period —about two weeks after corn silks are pollinated — sets the stage for kernel size later during grain fill. Vyn says it’s not just good nutrition, but also balanced nutrition during this period that means the plant is better prepared to handle stress. “And not just water stress, but also a nutrient stress, later in the season,” he says.
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Vyn explains that we know corn plants will remobilize N from leaves and plant parts to meet its needs during grain fill, but this actually hurts yield potential. Late N (at V10 or even past the V12 stage) encourages the plant to keep using N from the soil instead of remobilizing it from the leaves. This keeps that corn leaf solar panel green and working longer, extending the grain-filling period, resulting in bigger kernels.
Vyn joins RealAgriculture’s Bernard Tobin for this Corn School episode at the 2018 Southwest Agricultural Conference, to talk about the journey to higher corn yields, the importance of kernel number AND size of each kernel, and why keeping the corn plant green longer can boost the starch content of your corn crop.