Efficacy of Two Potassium Silicate Formulations and Two Trichoderma Strains on Fusarium Head Blight of Wheat

Abstract

Three rates (1.5, 3 and 4.5 g) of a granulated formulation and three concentrations (200, 300 and 600 mg L−1) of a liquid formulation of potassium silicate (KSi) were tested against Fusarium head blight (FHB) of wheat under greenhouse conditions. Granulated KSi gave slightly better control of FHB than the liquid KSi on wheat under greenhouse conditions in the two KSi trials. Granulated KSi (3 g) reduced FHB severity by 49% as compared to the pathogen-inoculated control treatment when disease severity was assessed 12 days after treatment application during the first KSi trial (p = 0.04). In the repeated trial, granulated KSi (4.5 g) reduced FHB severity by 54% as compared to the pathogen-inoculated control treatment when disease severity was assessed 12 days after treatment application. Control of FHB severity did not improve afterwards as a result of either the granulated or liquid treatments during the two KSi trials. Treatment with granulated KSi at the rate of 3 and 4.5 g had lower disease severities than the 1.5 g granular KSi treatment 12 days after plants were treated with Fusariumgraminearum F.32 during the two KSi trials. However, the liquid formulation of KSi at 200 and 300 mg L−1, KSi gave better protection than the application at 600 mg L−1. There was no significant difference in FHB severity on wheat heads, or the number of infected grains, after treatments with KSi alone, or KSi combined with the two Trichoderma formulations, T. harzianum strain kd and/or T. harzianum strain 77.