Non-proven essential elements

Silicon

Silicate anions can be enabled by their high degree of affinity to iron/manganese oxides and hydroxides to mobilise phosphate anions absorbed there.

The absorption takes place mostly passively in the form of the undissociated acid.
Within the plant, silicic acid is relatively difficult to move and is found either in amorphous form or as a galactose ester in the cell walls of the epidermis in monocotyledones, but inside the cells and in the plant hairs in dycotyledones.

Silicon is considered essential for certain cultures (e.g. rice) and beneficial for others.
Specific physiological functions have been sought for some time, but with little success.

Silicone is certainly involved in the stabilisation of cell walls. Silicone deficiency leads to an inhibition of phosphate storage in the ATP and sugar phosphates and also in lignin biosynthesis.

A good silicate content increases the tolerance of manganese by inhibiting the absorption of iron and manganese.

Tin

There are no references to tin in Amberger.
An old Cosmos volume (Herrmann Römpp, Spurenelemente, Kosmos, 1954, Stuttgart, Franckh'sche Verlagshandlung) mentions a so-called “Nutrient Solution A - Z” for a complete supply of trace elements according to R.D. Hoagland (1884 - 1949), which among other substances contains tin (II) chloride in small quantities.

Bibliography

[pro toto] Anton Amberger, Pflanzenernährung, 4th edition, 1996, Eugen Ulmer Verlag, Stuttgart

[1] Funktionen von Bor im Stoffwechsel höherer Pflanzen - Rheinische Friedrich-Wilhelms-Universität Bonn

[2] Press information No. 225/26. June 2001 Rheinischen Friedrich-Wilhelms-Universität Bonn