What's happening to my grafted lemon?
I'm from center Italy and I have this grafted lemon plant.
It is a lemon seedling as rootstock and it is inside a 40 cm (about 18") pot.
I budded it in July 2016 and put it into my home during winter.
Because of heavy rain and winds I decided not to put outside yet.
About two weeks ago I dispensed about 2 tablespoons of 15.9.15 slow release fertilizer.
About 4 days ago I noticed that smaller leaves started to develop brown spots in tips and edges and felt down.
I also noticed new spots developped in only 8 hours!
Also a bigger leaf developped spots in 8 hours and felt down after 24 hours.
Please, according to you, what is the problem?
Can fertilizer excess make the leaves fall down in a day?