As you seem to be indicating, sooty mold is, indeed, an aftereffect of the whiteflies. It grows on their honeydew excrement. So whitefly control will prevent further sooty mold. As for removing existing mold, a light horticultural spray oil will loosen it, and it will curl up. Then a blast from a hose will remove it. If this is an outdoor tree that could experience frost, I'd not use oil in winter. Wait until after any danger of frost.

Thank you so much for your response. This is indeed a tree that grows outside in the ground. It produced over 1000 oranges this year and I do not want anything to rob it of it's production value. All of my friends and family have reaped the rewards of this wonderful tree.

Thanks again,

Leubafr

I still have the sooty mold (since I was afraid of frost) and there are so many white flies swarming around I can hardly get close to check the tree. This is an OUTDOOR tree that is about 15'high. What do I do? It is now blooming and setting fruit along with growing new growth. Very heavy new growth.

Do as was suggested earlier,
"As for removing existing mold, a light horticultural spray oil will loosen it, and it will curl up. Then a blast from a hose will remove it."

Thanks again, will do. Didn't want to do anything that would keep my blooms from setting.

we have sooty black stuff on the top of some of the oranges in our tree, but donot see any white flies flying around...

Some scale insects and aphids are other culprits in the production of honeydew. The whole key to getting rid of the sooty mold is to locate and identify the insect(s) that are producing the honeydew.

Should I spray during bloom or wate untill after the fruit sets.