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Serving: IN

Use Common Sense With Yield Estimates

Specialist suggests adjusting formula, but is this the year to do it?

Bob Nielsen, a native Nebraskan, is proud of a black-and-white picture that would appear to come for the early 1900s. A horse is pulling one huge ear of corn on a wagon, with one man riding on the ear, and the other whipping the horse to get it to go faster. While it maybe the product of some of his computer graphic skills, it makes the point. Farmers want big ears, and this time of year, they want to know if they've got enough of those big ears to produce the type of yield they're looking for- usually a bumper crop.

Typical yield counting methods, or at least the most common one, calls for counting the number of ears in one-one/thousandth of an acre. To be consistent and no what's out there, do it in various locations within the field. Then pick three years at random by a set procedure, and count number of rows of kernels and number of kernels per row per ear. Use that information to get an average number of rows and average number of kernels per ear to use in the formula.

Then it's simply number of ears times number of rows of kernels times number of kernels per row, divided by a fudge factor. The fudge factor has typically been 90, based upon 90,000 kernels per bushel of corn.

"I think we can make the case that with today's modern hybrids, we ought to drop the fudge factor to 85," Nielsen says. "Counts we've taken typically come out closer to 85,000 kernels per bushel today. It's because of bigger kernel size with most modern hybrids."

Here's how much difference it can make. Suppose you came up with 28 ears, 18 rows, and 35 kernels per row. Using the normal formula and doing the math, that's 196 bushels per acre. A fudge factor of 90 was included in that estimate.

But if you replace 90 with 85 in the formula, here's how it turns out. Your estimate is closer to 208 bushels per acre. That's a large increase compared to the earlier estimate.

However, is this the year to convert the formula and use the higher estimate? With high heat and dry weather across much of Indiana the past several weeks, some are suspecting that kernel fill may not be up to par. With these new, modern hybrids it may be a matter of wait and see.