It looks different than our SRWW.  I believe mine is Feekes 4-5.  Never was very good at determining that because you really need to split plants to find the growing point at stage 6, above ground.

Isn't 90 lb a pretty big load of N at one time?  I have done that myself but don't like to.

I found this neat pictoral I was looking at.

http://www.ncagr.gov/agronomi/tissue/wheat6.htm

Nice job on the pictures.

Ed