Microbial Control in Greenhouses by Spraying Slightly Acidic Electrolyzed Water

Slightly acidic electrolyzed water (SAEW) has strong bactericidal activity and is relatively safe compared to other disinfectants. In vitro exposure of Escherichia coli and Bacillus subtilis to SAEW at a chlorine concentration of more than 25 mg/L for 3 min completely killed bacterial cells. When SAEW was sprayed in a greenhouse at a chlorine concentration of around 30 mg/L, the viability of airborne microorganisms was significantly reduced. On the other hand, SAEW spray did not affect the growth of eggplant and cucumber plants in the greenhouse. SAEW spray did not influence microorganisms in the soil or the plant leaf surface. SAEW could be used as a substitute for tap water to increase the relative humidity during the daytime, which is expected to increase photosynthesis. SAEW spraying reduces airborne microorganisms and improves the environmental conditions in the greenhouse.