Problem with musa banana
I noticed that on the leaves of my plant there are black drops and the back of the leaf it looks like having a fine cape of white dust (similar to the surface of certain succulents like sedum morganianum ) so I do not know if it's normal. could you tell me how to solve the problem, especially the black drops
Thank you for your question about your banana plant. The grey coating on the leaves would typically be indicative of a fungus of some type. I'm afraid I can't see the black spots with enough clarity to tell what they are. Here is a link to an article about insect and pathogenic problems known to bananas.
And here is a link to an article explaining causes of browning leaves.
I think that it would be wise for you to take your plant to your county Extension office so they can examine the leaves under a microscope to identify the problem.
Their contact information is here. I hope they can help. Good luck!