Going to chop drought-stressed corn for silage?
Get an accurate estimate of yield potential first, advises Bob Fanning, South Dakota State University extension agronomist, Winner.
Fanning spoke at the recent South Dakota State University Extension drought meeting.
"There's some corn out there," he says.
Given the high price of corn, combining even low-yielding corn for grain may be more profitable than chopping it for silage -- even if you or another livestock producer needs the silage.
To estimate corn yields, first determine the length of row needed to equal 1/1,000th of an acre. Divide 43,560 square feet by the row spacing (in feet) and divide that 1,000. For example, a 30-inch row spacing is equivalent to a 2.5-foot row spacing (30/12=2.5).
Next, plug in the numbers into the formula -- (43,560 / 2.5-feet) / 1,000 = 17.42 feet.
Using the above example, you need to measure 17.4 feet at several locations in the field. Count the numbers of ears developing in the row in the designated area. Record this information and average the number of ears after scouting the field.
Pick a couple of ears randomly from the survey area. Count the number of rows per ear and the number of kernels in a selected row. Average the number of both counts and multiply them to determine the average for the number of kernels per ear. The kernels per ear are then multiplied by the average ears per acre giving the kernels per acre.
There around 90,000 kernels per bushel in normal corn. Droughty corn typically runs between 100,000 to 110,000 kernels per bushel, depending on the severity of the stress. To determine the estimated yield, divide the kernels per acre by the estimated kernels per bushel.