Regulation of temperature, humidity and leaf wetness duration can prevent disease development. An integrated approach is desirable for the successful management of Botrytis blight. Control weeds, and remove plant debris between crop cycles and during production. Space plants to allow for good air circulation and reduction of humidity within the canopy. Reduction of humidity by heating and ventilating is relatively inexpensive compared to the loss of revenue that can result from Botrytis blight and other plant diseases.
Warm air holds considerably more moisture than cool air.
To prevent excessive humidity and dew formation, turn on the heat and open the vents. The warm humid air is ventilated to the outside as the cooler outside air is drawn into the greenhouse. This air exchange should only take 5 or 10 minutes. The energy necessary to run fans and to provide heat is not significant. Under some conditions, this cycle may have to be repeated several times during the evening.