moisture window for baling alfalfa

I've just retired from the job that paid for the farm and I now have the time to try to do hay right.  After reviewing several of the threads here, I think I understand the pros and cons of most of the steps involved in producing good alfalfa hay - leaves retained, no mold.  However, I am confused as to just when to start baling.  Let's say at the end of day 2 the stems are dry.  We rake on the morning of day 3 as the dew comes off.  On the morning of day 4, we have our hygrometer set up near a windrow and our delmhorst moisture tester is in hand. 

 

Now, in a recent thread, two contributors said we should begin baling when the relative humidity reaches 65%.  (We are making round bales.)  But, based upon very limited experience, I expect the tester will show the moisture in the windrow to still be in 20's.    Am I wrong OR do we expect the dry stems to balance out the moisture in the leaves?  Under these circumstances, is our moisture target in the bales 18% or less? 

 

Thanks.  My wife approves of my visiting haytalk - considering the alternatives.

 

 

moisture window for baling alfalfa