Salt in the soil? Too much fert?

Jeff

That would be my guess as well...when was the last time you fertilized...what did you use and how much? They are very susceptible to fertilizer burn especially when very young or newly planted. Also have you sprayed the leaves with anything? If you did...maybe part of that is sun 'burn'...just a thought?

Good luck!

The other leaves appear to have tip burn, a common symptom of overfertilizing.

I haven't fertilized the tree since last fall. Is it still likely fertilizer/salt burn? Assuming yes, is there anything that can be done to reduce the salt i. the soil?

If it helps with diagnosis I also noticed some leaves with black material that I can scrap off of the leaf. Don't know if that is related or something else that is wrong with the tree.

Ian

The black stuff is probably sooty mold, which is more of a visual nuisance than anything else. Summer rains will wash it away.

The leaf abscission combined with the burned tips sounds characteristic of salt burn, which can take a few months to show. You can flush the soil with water, but my guess is that your tree will be fine. Mangoes are very sensitive to salt/ammonia burn. In fact, Dr Campbell once told me that you can kill a mango tree by planting a fish in the same hole (which will eventually rot and generate ammonia).

Jeff