Silicon improves strawberry plants nutrient uptake and epicuticular wax formation in a rhizosphere cooling system

Bioavailable silicon (silicic acid) is considered to be beneficial for plant growth and development. This study therefore aimed to determine the effects of silicic acid [Si(OH) 4 ] and potassium bicarbonate (KHCO 3 ) application on strawberry ( Fragaria x ananassa Duch) plants’ nutrient uptake and leaf wax formation. The strawberry plants (cvs Festival and Fortuna) were grown in a rhizosphere cooling system (RCS) at a mean rhizosphere temperature of 18°C ±2. Accumulation of plant nutrients in the plant parts was analysed by using inductively coupled plasma – optical emission spectrometry (ICP-OES), whilst the formation of wax on the leaves was observed with scanning electron microscopy (SEM). The results showed that plants given 0.25% (v/v) Si(OH) 4 via the roots had the highest amount of silicon accumulated in the leaves, roots, and crowns of both cultivars. The greatest amount of Ca and Mg was also found in the leaves of cv. Festival plants treated with 0.25% (v/v) Si(OH) 4 through the roots; whereas in cv. Fortuna, Ca, Mg and P had their highest amount accumulated in the leaves of plants sprayed with 0.25% (v/v) Si(OH) 4 mixed with 0.5% (s/v) KHCO 3 . Root application of the KHCO 3 treatments on the other hand, limited Ca, Mg, Mn and Fe uptake into the plant parts. The leaves of the Si(OH) 4 treated plants were covered with a denser mass of wax when observed under SEM. Thus, Si(OH) 4 application was found to enhance strawberry plants’ uptake of essential nutrients and also improved the formation wax on leaves, that may delay plant diseases invasion.