Question
My young plant has black sticky residue with alittle white powdery looking residue It is on only a few leaves.
What have I got and what do I do?

Answer
Sounds like scale insects.  If you dig into the cottony stuff you will find a small insect that is possible cigar to oval shaped and closely appressed to the leaf and stem surfaces.  The cottony stuff is a protective covering.  The insects feed and leave behind the sticky substance called honeydew which then attracts a black mold that grows on the sugars in the honeydew.  The honeydew and sooty mold do no harm to the plants themselves unless it ecomes real heavy and covers the leaves, preventing sunlight from reaching the leaves.  The problem are the bugs feeding that can dry the leaves and cause defoliation and even plant death.  If the plant has edible fruit you are limited to products that can be used.  Safer's Insecticidal Soap will work but has to be sprayed frequently, say every 3-4 days.  You can also get a Q-tip and dip in heavy mineral oil and coat each of the cottony areas if there are just a few that you have to do this too.  Each of these techniques will kill the scale insects.  If you would like a recommendation for harder chemistry I can make those for you as well.  Please respond back if you need additional information.  Good Luck.