Posted by: usset001 | July 9, 2014

Minnesota corn conditions and yield potential

MN corn yields 1984 2014Based on a simple linear regression of the last 30 years, Minnesota trend-line yield is 175 bu./acre in the current crop year. However, Minnesota corn conditions (CCI of 367 – see below for an explanation) as of July 6 are average, at best, and modestly below average if we focus on conditions over the past decade. My best guess at this point is an average yield of 165-170 bu./acre in Minnesota.
The crop condition index (CCI) is based on weekly USDA crop ratings. It’s a conversion of the crop conditions into a single index. The CCI is calculated as follows…
(% excellent * 5) + (% good * 4) +(% fair * 3) + (% poor * 2) + (% very poor * 1) = CCI
To calculate the Minnesota corn CCI as of July 6, I did the following math…
(14% excellent * 5) + (50% good *4) +(27% fair *3) + (7% poor * 2) + (2% very poor * 1) = 367
MN Corn ConditionsAn index of 500 reflects a crop in excellent condition, 400 is good, 300 is fair, 200 is poor and 100 is very poor. As of early/mid-July, this index has been as low as 230 and 244 in 1988 and 1993, respectively. A CCI index above 400 is not uncommon for this time of year, occurring most recently in 2009 and 2010. The last two years we had a MN CCI index for corn at 367 or lower were 2013 (363) and 2007 (367), and both years ended with below trend yields. However, as recently as 2004, the MN CCI corn index was at 361 in early/mid-July and we ended the year with a new MN yield record (159 bu./acre vs. 151 trend). Conditions today are important, but matter less than growing conditions as they unfold over the next few weeks.

For the record, the highest CCI ever recorded for the Minnesota corn crop was 438, in the last-half of July, 1994. Minnesota corn yields in 1994 set a state record of 142 bu./acre, 15 bushels better than the previous record.


  1. […] is sporting a crop conditions index (CCI) of 359, somewhat below average for this time of year (see my previous post for an explanation of the CCI). Despite the below average CCI, I’m holding out hope for a trend-line yield for 2014, assuming […]

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