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This is a DryGair article contributed to the Cannabis 2020 magazine.

Bud rot, powdery mildew and Alternaria are some of the most dreaded words in cannabis cultivation. Destructive diseases caused by even brief periods of high relative humidity, which in a greenhouse environment, could be every night. The best way to avoid these problems, is with consistent climate control.

Drygair humidity and temperature levels graph

Growing high quality cannabis requires tight control over conditions, from strict lighting regiments to humidity control, all in order to grow a consistent, mold free, high grade product. But controlling conditions in a greenhouse is extremely difficult. Unlike indoor operations, greenhouses are susceptible to the weather outdoors. If it’s cold outside, temperatures inside will start to drop and vice versa. The same is true for any climate parameter.

Humidity buildup becomes a real peril when the sun sets. Screens are set up to block any light from infiltrating the greenhouse, the air outside is cold and moist, and the plants inside are transpiring. This is the reason humidity spikes, prompting water to condense on equipment, infrastructure, and plants. The most dangerous periods being dusk and dawn, when conditions change rapidly. During these periods it is very difficult, albeit crucial, to create the optimal conditions for cannabis inside the greenhouse.

Consistent Climate Control to Improve Yield and Quality

The solution to greenhouse humidity management comes from DryGair, a system developed at the Israeli agricultural research organization – Volcani. The concept is simple and accommodating to cannabis’ strict requirements. In a closed greenhouse, during the night, DryGair reduces humidity by creating dew point conditions and condensation inside the unit, instead of on the plants. The unit disperses the dry air evenly throughout the space, in 360°, with the use of its patent-protected hood design.

The graph below displays the relative humidity in a cannabis greenhouse, during a 6-day period. It is noticeable that during nights in which DryGair was operating, relative humidity levels were not only restricted through the night, but also reliably consistent throughout the entire period.

Creating consistent, homogenous, optimal conditions is the key to growing quality, disease free cannabis. With DryGair as a growing tool, this is now, more than ever, possible to achieve, in all growing facilities.