Soil Silicon Application Alleviates Drought Stress in Sugar Beet ( Beta vulgaris L.)

Abstract

Background : The increasing frequency and intensity of drought events have led to yield and quality losses in sugar beet production in temperate regions in Central Europe. Under arid conditions, silicon (Si) application reduced beet yield losses under drought. Similar data for temperate climates are missing. Moreover, most studies have focused either on foliar application or drip irrigation with Si. Aims : The aim of this study was to determine the effect of soil Si application on the yield and quality parameters of Beta vulgaris in a temperate environment. Methods : Field trials were conducted at three different sites in Germany and Austria. Different Si fertilisation rates were tested (Site 1: 0, 37, 78 kg ha −1 ; Sites 2 and 3: 0, 50 kg ha −1 ). At Site 1, an irrigated control and a non‐irrigated drought treatment were established. At Sites 2 and 3, irrigation was not possible. Yield and quality parameters were determined after harvest. Results : At Site 1, drought stress reduced beet yield by 30% without Si application. Under drought conditions, Si led to a significant reduction in beet yield and net sugar yield losses of 17% and 18%, respectively. Quality parameters were only affected by irrigation, not by Si. No natural drought stress occurred at Sites 2 and 3. Conclusions : The results indicate that Si fertilisation could become a relevant tool for sugar beet cultivation in a changing climate. The mechanisms behind this yield effect are yet to be determined. More data are needed to propose clear Si fertiliser recommendations for sugar beet cultivation.