Abstract
Strawberries are a high-value crop in the United States due to their increasing demand and nutritional benefits. Strawberry production faces significant losses due to gray mold fruit rot caused by Botrytis cinerea. While fungicides provide major control, concerns about residues and the evolution of fungicide resistance demand alternative approaches to disease management. In this context, our study evaluated the potential use of potassium silicate (K(2)SiO(3)) to enhance agronomic traits in plants, elucidate its role in combating gray mold in strawberries, and identify the responsible genes. Two strawberry cultivars (Flavorfest and Rutgers Scarlet TM) grown under high-tunnel field conditions were foliar-sprayed with different doses of potassium silicate (K(2)SiO(3)) (0, 2, 3, and 4 mL per gallon of water). Silicon accumulation and agronomic traits were measured, and antifungal effects were assessed through in vitro assay and post-harvest fruit treatments using Chandler and Ruby June cultivars and molecular analysis using the silicon transporter genes. The 2 mL per gallon treatment showed the highest silicon concentration in leaves and phytolith formation, with limited translocation to roots, and significantly increased plant width and marketable yield. The effective concentration (2 mL/gallon) also reduced B. cinerea growth under in vitro conditions and lowered infection on postharvest-treated fruits, coinciding with enhanced expression of silicon transporter genes. Our study reports that moderate application of K(2)SiO(3) as a foliar spray improved plant growth and production, suppressed gray mold under in vitro conditions, and in postharvest treatments. Increased expression of transporter genes indicates the plant's response to its application.