farmpro11
8/20/10
Here is a table of Iowa ear weights and avg temps(day and night) in
August the last 5 years.
2005 .36 ear weight 71.5
2006 .34 ear weight 72
2007 .335 ear weight 74
2008 .335 ear weight 69.8
2009 .35 ear weight 68.1

So in Iowa the last 5 years they have averaged approximately .344 ear
weights(not including cob). Also the avg temp(day and night) as avg
71.1 degrees.

Just for kicks in 2004 avg temp was 66.2 and ear weight was a record
at .368.
In 1995 the avg temp in august was 76 degrees(the warmest in last 20
years) and the ear weight was a very light .285(the lightest).

2010 ?? ear weight// avg temp so far is 75 in Iowa(not official).
Since the USDA takes a 5 yr avg on ear weights on the Aug report I
think no doubt ear weights will be down 5-10% from the 5yr avg
whenever they actually weight it. Also keep in mind that it has been
even warmer in ill,ind,ohio this july/aug which will no doubt lower
the ear weights even more.

I am going with a yield of 150-155 solely on ear weights being .31-.32
this year which is 7-10% less than the 5 yr avg of .344. i doubt we
get ear weights as low as 1995 because of the newer genetics now.

I have no doubt if you just count kernals and populations that you
come up with an avg yield of 162 on this years crop...but with the
lighter ear weights it will be 7-10% less I have a national crop at
146-151. Probably closer to 151 based on the newer genetics. And
since pro farmer came in with a yield of 169 with AVERAGE ear weights
Iowa could really do closer to 160-163. USDA has them at 179 now.
Illinois at 180 is a joke to in my book since they have been even
warmer than Iowa all of july and august. I say it will be sub 170.
Time will tell!!