North American Fruit Explorers mailing list at ibiblio

[Jim Fruth <jfruth@uslink.net>]

    Zinc coated nails are unlikely to do a tree any good because the tree
cannot dissolve elemental zinc.  The preferred method of applying
supplemental zinc is a foliar spray using chelated zinc or (second best)
zinc sulfate.
-- 
Jim Fruth
Brambleberry Farm
Pequot Lakes, MN
www.bberryfarm.com
Jams, Jellies and Syrups
(218)568-8483 [Store]
(218)831-7018 [My cell]

An old orchardist I once knew had a novel way to apply zinc.  He drove
a bunch of galvanized shingle nails into the trunk.  It specifically
had to be shingle nails because they have very wide heads and short
shanks.  As a result, as the tree grew, it pushed the nail out with the
expanding trunk instead of growing over it.  That way, if the tree had
to be cut, the nails could be found to remove them easily.
I never had a need to use the method, but this fellow swore by it.
-Lon Rombough