Modify moisture

Humidity reduction methods

Spring and fall are times when humidity-related diseases usually peak in the greenhouse. Sunny days increase the transpiration of moisture from leaf surfaces and evaporation from soil surfaces. The warm air holds the moisture in vapor form. At night, as the air cools to the dewpoint, condensation occurs and water droplets are formed on cooler surfaces such as the glazing and leaves. This moisture promotes the germination of fungal pathogen spores such as botrytis or powdery mildew. There are several ways to reduce the humidity level.