The Role of Foliar-Applied Silicon in Improving the Growth and Productivity of Early Potatoes

Climate change is leading to a decline in global potato production. To ensure food security, it is essential to adapt cultivation practices to the changing climate. The effects of foliar-applied silicon on potato growth and productivity under various hydrothermal conditions were investigated. Potato plants were treated with three Si-based biostimulants: Actisil (6 g of Si and 20 g of Ca per liter; choline-stabilized orthosilicic acid; Chol-sSa + Ca); Krzemix (6 g of Si per liter; choline-stabilized ammonium metasilicate; Chol-sNH 4 -Sil); and Optysil (93 g of Si and 24 g of Fe per liter; sodium metasilicate and iron chelate Fe-EDTA; Na-Sil + Fe-EDTA). Biostimulants were foliar-applied twice, at the leaf development stage (BBCH 13–15) and two weeks after the first treatment, at 0.5 L/ha in each treatment. The plants treated with biostimulants were taller and produced greater above-ground biomass and a higher tuber weight than the control plants (without a biostimulant). As a result, the total tuber yield was higher, on average, by 10% to 13% and the marketable tuber yield by 11% to 15%. The plant-growth-promoting and yield-increasing effects of the Si-based biostimulants depended on the hydrothermal conditions during potato growth. Chol-sSA + Ca (Actisil) applications were the most effective. Na-Sil + Fe-EDTA (Optysil) produced better results during a warm and very dry year, while Chol-sNH 4 -Sil (Krzemix) was effective during colder years with a periodic water deficit. Silicon foliar application can be a new method for increasing early crop potato yields under water shortage conditions.