Ag Weather Forum

Hoping For Half

Bryce Anderson
By  Bryce Anderson , DTN Senior Ag Meteorologist
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Darrel Good and Scott Irwin at the University of Illinois posted an interesting study on the topic of "How Much Of The 2013 Corn Crop Will Be Planted Late?" the week of April 22nd. Here are the key points of their study, and I updated it with conditions and figures from the April 28 USDA crop progress report.

The Good & Irwin research shows that, since 1986, the term "late planting" regarding corn begins on May 20th. Also in that time frame, the long-term average of late plantings is 15 percent. From late April through the 20th of May, a typical season brings about 50 percent of those days suitable for field work. And, on average, just under 5 percent--4.8 percent to be exact--of the U.S. corn crop can be planted in a typical day.

Now to the update---

5 percent of the U.S. corn crop was planted as of April 28. That means that to reach 85 percent planted by May 20, 80 percent of the corn crop will need to be planted in the 21 days from April 29 through May 20. Is that possible? Maybe--but here's the way a typical activity and field work rate looks:

With 50 percent of those 21 days suitable for field work on a typical schedule, this suggests that there will be about 10.5 days suitable for field work April 29 through May 20. With an average planting rate of 4.8 percent per day, the total is 50.4 percent additional planting by May 20th. That 50.4 percent added to the 5 percent already planted results in a sum of 55.4 percent, leaving just under 45 percent of the corn crop to be figured as being planted late.

Again, using the 4.8 percent planted per day, how many of the next 21 days from April 29 need to be suitable for field work? Almost 17--16.7 days.

That's where the weather forecast has thrown a real knuckleball--and why we saw that big spike in corn prices to start out this week.


I'm on Twitter @BAndersonDTN

The full University of Illinois report is available at this link:…



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Paul Beiser
5/1/2013 | 6:48 PM CDT
if it rains every third day... it won't matter if 20 of 30 days are dry cause the planters will still be parked in the sheds.