I think it would be smart to assume you have a boron deficiency. The easiest way to overcome this would be to take boron supplements and see what happens. 30 mg twice a day for 10 days should show impressive improvements. You can get this much boron from taking 1/8 tsp of borax dissolved in water per day.
Please note that borax is not the same thing as boric acid and is not an acid at all. It is no more toxic than table salt.