Hi, I have a large orange tree in my backyard that was giving fruit 2X's a year until last fall. Leaves turned yellow, brittle, and fell off. we sprayed the tree for fungus / disease but no new leaves. Now its almost black, and the bark is easily peeled off if you touch it. It went from great to dead in a month. Now its Spring and no new leaves. I think its a goner but I'd like to know what caused it. Any ideas? Thanks Aldenski