The effect of foliar-applied Ca and Si on the severity of powdery mildew in two strawberry cultivars.

Abstract

Powdery mildew causes significant economic loss in strawberry crops in South Australia. The cultivar commonly grown (Selva) is susceptible to disease and the chemical fungicides available to growers do not provide satisfactory control. The objective of this study was to investigate the effect of foliar-applied Ca and Si as a control for powdery mildew. Calcium chloride (Stopit®, Phosyn Plc) and potassium silicate (Kasil 2040®, PQ Corporation) were applied as foliar sprays to the cultivars ‘Aromas’ and ‘Selva’ during the 2003/2004 growing season. Powdery mildew symptoms were reduced only when both fungicide and potassium silicate were applied while potassium silicate alone or calcium chloride had no significant effect.