Control efficacy of milk concentration against powdery mildew of strawberry

Abstract

The aim of this study was to determine the effect of milk as one of the environmental friendly materials that substitute chemical fungicides for control powdery mildew (Sphaerotheca aphanis) of strawberries (Fragaria × ananassa Duch.). 'Maehyang' and 'Akihime' varieties planted in greenhouses were evaluated for the control of powdery mildew. Applications of 5%, 10% and 20% milk had much better effects on controlling powdery mildew. In particular, 10% milk showed a higher efficacy than other concentrations applied onto strawberry in greenhouse experiments. Foliar spray application of 10% milk was effective for powdery mildew, whereas drench application was not. Also, foliar spray of 10% milk was able to accelerate more firmness and calcium contents of strawberry fruits than the nontreated. The 10% milk applied with fertilizer salts (Ca(H2PO4)2 H2O and KH2PO4) showed there was a similar efficacy to 10% milk alone in greenhouse experiments. White crystals and cracks on strawberry fruits appeared by 20% milk. This result indicated that 10% milk was a useful substitute for fungicides to control powdery mildew of strawberry. © The Korean Society of Plant Pathology.