While half of Iowa's corn crop was planted by mid-May, much was pushed back several weeks. Some fields were replanted more than once and as a result pollinated into August.
The bottom line for many growers is that corn maturity has been delayed. The problem with harvest may be a wetter than normal crop created by a combination of late planting and then impacted by hot, dry conditions during grain fill.
Iowa farmers are now expected to harvest about 13.5 million acres of corn, that's 200,000 acres less than last year's drought ravaged crop. The latest USDA estimate, based on early September conditions, is that the Iowa crop would average 162 bushels per acre; that's below the 30-year state trend yield by 17 bushels.
Corn yield and grain moisture will vary widely across Iowa during harvest this fall
Iowa State University Extension farm management specialist, Steve Johnson, sums up the current state of the 2013 Iowa corn crop: "The variability of corn yields and moisture levels is going to be large across the state. Much depends on the corn planting date and the water holding capacity of the soils."
Some corn plants that died prematurely may already be harvested, but much of Iowa's crop will be slow to dry down in the field. It will need to be harvested and dried down to near 14% or 15% moisture content to avoid a moisture discount or extend storage time for bushels to be marketed later. Delivery of wet corn that's sold will carry a moisture discount at roughly 2% times the points of moisture above 15% times the cash contract price.~~~PAGE_BREAK_HERE~~~
For corn harvested at 25% moisture and averaging 170 bushels per acre dry, that's about $90 per acre with corn valued at $4.50 per bushel, notes Johnson. This amount roughly equals the cost of commercial drying charges using a 1.4% shrink factor and 4.75 cents per point of moisture. Drying and storage of corn may be a problem as harvest gets underway.
With wetter than normal corn coming out of fields, corn dryers will be running long, hard hours
"The key thing for a grower is to think ahead about corn moisture levels, drying and storage costs--be prepared," Johnson says.
He notes there's an abundant supply of propane out there. The challenge this fall--if harvested grain needs a lot of drying --will be having the propane in the right place at the right time.
Perhaps the most important factor in dealing with corn at higher moisture levels at harvest is getting the combine set right. Some things to remember, according to ISU Extension ag engineers, are:
*A properly adjusted combine can handle corn between 20% and 30% moisture, but expect grain damage to increase unless careful attention is paid to combine settings.
*Be sure to select a ground speed adequate to keep separator and cleaning shoe at full speed. Adjust your hydrostatic transmission to maintain the engine near rated speed under varying crop conditions.
*Operate the corn head as high as possible to reduce getting wet plant material in the combine, which can significantly reduce the machine's ability to thresh and separate the grain.
*Before changing concave clearance, make sure it is level side-to-side in a conventional combine or front-to-back in a rotary combine so that the adjustment is uniform.
"While corn harvest may begin later than normal this fall," notes Johnson, "farmers will want to be prepared."