Question
Our Fat Albert seems to be attack by a disease or insect at the very top... The new growth last Spring started to decay and wrinkle.  Progressively over the Summer it gained the lower new branches... it is now 12cm from the inital top.  
Could you tellus what it is and what to do?  Thank you
I can you a slide if necessary.

Answer
Paule:

It could be either an insect or a disease within the top portion of the stem tip. Difficult to tell w/o a lab exam.

If you can reach the top, I'd suggest just snipping out the brown portion. Locate where the green portion meets the brown and go down just into the green to make your cut.  You can contact your local county Agricultural Extension office (usually in the county courthouse building)to arrange for a lab exam of this stem to ID if it is an insect or a disease.

Regards
Steve