Boron leaches at high (pH & temperature) & precipitates at low pH & low temperature.
Boron is a co-catalyst to (Calcium, Potassium, Magnesium & Sodium), as well as Gibberellins, Auxins, Cytokinins, Abscisic acid, Ethylene.
It is just as easy to accidentally have an Abscisic acid reaction as an...