Dirtyshoes, I am not an expert and may be it was not the right way of doing it but last year I had the same problem. At first, I did what you already done : washed all leaves and then used a Liquid Copper applications. The tree is healthy and blooming and I did not see the mold again. My tree is also very young.

I've only used soap and water to wash away sooty mold myself.

You are right in that the mold is not the problem, it's the insects that secret honeydew. White fly is also a problem that covers plants with black gook.
Best bet is to contact your local county extension office and find out what they recommend.A systemic pesticide would take care of the problem but would also end up in your fruit.
You could spray 1 Tbs ivory soap + 1 Tbs oil to a gallon of water, but you would need to do it repeatedly.
Good luck.

Thanks everyone for your input.

Mocro, I'll look into the liquid copper. I'm glad your tree is doing well.

Katkin and coffeemom, if it reappears, I'll continue with the soap and water. I'd rather not get into using pesticides. Also, I'm going to check it today for the white fly you mentioned.

Coffeemom, how often would you spray the soap,oil, water solution?

One or two applications of the soap and water should do the trick. If I were you I would skip the copper, its like putting stuff right on your fruit that you are going to eat,the soap and water will do the job.

Organicide! Fish oil, sesame oil and a hardener! Will suffocate any sort of mold or fungi.....one of the more dense oils that works great! We use it on everything, including the asiatic scale on my Sago! I do mix an equal amount of malathion with it for the scale! Stinks, but works great and a bottle will last for years.

The mold is just a symptom of a larger problem. It is there because you have some kind of insect eating your plant and secreting honeydew, which is what the sooty mold grows on as it leaks and drips out of their butts!

Look close, especially slightly above concentrations of sooty mold, and you will see something. They're likely scales, which are little brownish disk looking creatures that are often hard to see.

I have had good success using paraffin oil for sapsuckers like scales on mangoes. neem oil or fish emulsion will also work. Once the scales are dead (I spray every day IN THE EVENING for 3 or 4 days, then do it again in a week To get any new hatchlings.) Once that's done and the insects are dead, only THEN can you clean off the sooty mold with soap and water.

Really sooty mold is a good thing because it alerts you that a problem exists.

Boy, am I learning alot!

I checked the bottom of the leaves and didn't see any bugs. I did see what appears to be white circles though.

With the oil sprays, for instance, the neem oil....what is the oil to water ratio? Do I spray both top and bottom of leaves?

After cleaning off the leaves, I have not noticed any new mold on them. Should I hold off on spraying?

Walli, what do you mean by hardener?

Thanks everyone, I really appreciate all the responses.

It hardens the oils. Alot more dense an oil than some of the others, but still let's the leaves do their thing. Fish oil leaves a residue which sometime discourages reinfestation. 3 tablespoons to a gallon of water. HD and lowes both carry it.

You may have spiraling whitefly. I haven't yet had to deal with them in any quantity. Good luck!