I can not see the original message but back when I was a Research Assistant
we did Date of Sowing or Seeding studies for Winter Wheat. Soil temps were
recorded. It was more yield related but would give you something else to
search for.

John!

wrote in message
oups.com...
You might check the following links:

http://www.ScienceOxygen.com/idea.html

It might not help you directly. But you might
start from there to collect some information..