Some good thoughts Darin.

1. I agree that if you have other issues like your sidewall compaction that one years data becomes a lot more suspect. In our case although it was somewhat of a dry spring we had almost perfect stands and growing conditions early.

2. Funny, but we had about the same thinng here concerning maturity in different varieties. We missed our 4th of July rain this year (90% chance) and this is the one that makes or breaks up. However we did get a decent rane a week or ten days later which we are more likely year to year to not get. The fuller season corn for the most part had just hung on long enough to benefit quite a bit from it where the early stuff not so much - so my guess is like you yields will not be a lot different with the exception of the very worst where the ears dropped on the full season before the rain.

Typical was probably a bad word to use. This really was not typical for us the more I think of it (usually wetter early) but the late season drought stress is very common and the most likely yield limiting factor for us.

I like your idea of comparing where new zones are drawn compared to the old ones. And in reality I probably will not use only one year data except on quite a bit of land that we just took on this spring where we only will have one year. On my other stuff will probably just average the year in like I have been. Might try a few fields though just to see what difference it would make, current year compared to 4 years averaged.

Mostly wanted to get some good discussion and thinking going on and get feedback. I think in certain circumstances, along with the managers knowlege of his farm, one years data can be useful by itself to make management decisions. Probably don't want to bet the whole farm on it or go off the deep end changing inputs but some minor adjustments in the indicated directions should be ok.

John