Something's amiss. I have 4 fruit trees in a row approximately 60' long. The Clementine is in the middle. Last year it gave 1 fruit. This year I added compost and mulch in November and January. Had flowers and lots of fruit which is now turning yellow or brown and falling off. The leaves are a bit leathery, yellowing and not looking good. I added Bandini 15-15-15 fertilizer in March which helped some.

The other Valencia Orange, Lemon and Lime are doing fine.

Any thoughts?

Could it be a virus? When my Adenium's leaves look that way, sometimes curved, and lumpy, it's a virus. I'd put a few leaves in a ziplock and take them to a nursery or someplace where they could help identify.

Hope this helps!