North American Fruit Explorers mailing list at ibiblio

["Lucky.Pittman@murraystate.edu" <Lucky.Pittman@murraystate.edu>]

Jim,
If removal of the trees is a desirable thing for you,
and you're not opposed to limited, targeted herbicide
application, cutting down &/or girdling the trees and
concurrent application of an appropriate herbicide
labeled for stump treatment, like Brush-B-Gon,
Pathway(Tordon), Garlon, etc., will quite effectively
kill those trees, and ultimately, their roots.  
I use Pathway on undesirable tree species, like
sweetgum, honeylocust, and black locust when it's in
an undesirable location.  Total kill with no stump or
root sprouting.

http://www.forestry-suppliers.com/iCat/Cat59/full.asp?page=166

Lucky