Thanks for your help. Very insightful. I would like to show you, if a may, one more picture regarding your observations and perhaps you will be able to tell me if it is relevant. It relates to the way the leaves are drying out at the end - which I interpret that you are right and it has a fungus due to too much water, rather than from the stem which would indicate - I believe - a lack of water. Please let me know if you concur.
Great help. I am going to apply the bone meal as you suggested.
I appreciate your help very much.