Maple tree sapling, what would cause this injury/deformity?

Question

Green (sugar?) Maple little over 6' tall.

http://i2.photobucket.com/albums/y13/Taurus01979/Temp/MapleSapling.jpg

(Ignore the kink in shape, it just grew crooked a little it's first summer.)

I've read everything from squirrel damage, winter/freeze crack damage, to fungus. Any ideas what it really is? I think it's parent had similar, and I know a red maple had a patch of bare wood as well. With the thick rounded edge of bark around it. Is there any way I can help it heal or protect the area?

Answer 1

yes this happened to my dad when he trimed ours dont trim the top

Answer 2

It looks like a poor pruning job or being cut by a lawn mower or weed whip.  Once the tree has a wound it allows insects or fungus to do damage to the tree - the tree responds and walls out the fungus or insects with the thick bark.  it should heal on it's own.