Potato (<i>Solanum tuberosum</i> L.) Growth in Response to Foliar Silicon Application

Abstract

As silicon induces abiotic stress tolerance in crop plants, it was hypothesized that foliar silicon application could improve potato growth in an early crop culture. The effect of dosage (0.25 dm3·ha−1 or 0.50 dm3·ha−1) and time (the leaf development stage, BBCH 14–16, tuber initiation stage, BBCH 40–41, or both the leaf development stage and tuber initiation stage) of application of the silicon-based biostimulant Optysil (200 g SiO2 and 24 g Fe in 1 dm3) on potato growth was investigated. Optysil caused an increase in plant height and above-ground plant biomass, enlarged leaf area and decreased leaf weight ratio (LWR), and, as a result, increased tuber number and tuber weight per plant. The effect of Optysil depended on a water deficit during potato growth. The average tuber weight per plant in the cultivation treated with Optysil was higher by 23% under periodic water deficits during potato growth, and by 13% under drought conditions, than in the cultivation without the biostimulant. Dosage of Optysil had a significant effect on above-ground plant biomass and leaf area in the warm and arid growing season. Under drought stress, Optysil at 0.50 dm3·ha−1 stimulated potato growth more than at 0.25 dm3·ha−1. Under periodic water deficits during potato growth, the time of Optysil application affected potato growth more than the biostimulant dosage. The plants produced greater above-ground biomass and had a larger leaf area with two Optysil applications; one in the initial plant growth period (BBCH 14–16), and a repeated treatment in the tuber initiation stage (BBCH 40–41). The tuber weight per plant was positively correlated with the plant height, above-ground plant biomass, leaf area, and LWR.

Keywords

• sodium silicate
• biostimulant
• plant height
• above-ground biomass
• leaf area
• tuber weight