Stan, I haven't seen a mango yet that didn't have some of what you show in the pics. Probably a little bit of a fungus as they are prone to. Get a good copper fungicide and spray the plant as directed. I wouldn't be too concerned though.

Hi,
I planted a mango tree bought from a nursery 8 month ago and after a while the tip of the tree started changing the colour from green to black and I 've noticed a whittish thick liquid around the growing tip. Then the leaves started changing the colour to brown and then they become crispy. I sprayed the tree with a sulphate but so far no result. I 'd like to attach some pictures but I don't know how to do it. Could you please help me to save the tree.
Thank you.
Adrian

I agree with Jay.
Adrian, I'm not quite sure which copper spray I used but it sounds like you have the same problems. Spray the tree when it is pushing out new buds/growth. Once the symptons already appear on the leaves, spraying doesn't seem to make much difference. So once you start seeing the next growth flush, spray the tree. I hope this helps, let us know how it goes. To make it easy, you could attach the pictures in the gallery section of the forum and then just link it here.