Question
"I have a small holly, I think burford, which is dropping new leaves (new growth this year, in middle tn.), new stems look healthy, putting on 6-8 inch new growth with new leaves.  In last week, started dropping all of the new leaves and old leaves turning yellow.  No spots.  The leaves that fall off are black at the base of the leaf stem where they meet the main stem.

Answer
Ralph:
I don't think this may be a disease, but rather some type of temporary "shock".  Have you had a sudden drop in temperature lately? This can do it sometimes, especially if the plants are well established in the landscape. You might also consider reviewing any types of sprays that may have been applied also.

Regards
Steve