Cannabis Cultivation Success with UV Air & Surface Disinfection

Germicidal UV Applications / Farming & Aquaculture / Cannabis Cultivation

Cannabis cultivation lab, growing room, and leaf with $100 bill

An Industry Cultivating Interest

Since many U.S. states have legalized marijuana, the use of cannabis and its derivatives such as CBD oil and hemp fiber have skyrocketed. The cannabis cultivation market in the U.S. alone is worth tens of billionsopen_in_new of dollars and is growing every year. This increased need has resulted in an explosion of dispensaries across the country.

With the increase of retail outlets for hemp products comes a greater need for cannabis cultivation facilities. But growers face numerous challenges. In 2016, one laboratoryopen_in_new found that 80 percent of cannabis product entered in a California competition came back tainted with mold, pesticides, and harmful solvents. To supply quality cannabis, cultivation facilities must go beyond traditional methods and include ultraviolet disinfection to treat their air, surfaces, and water.

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Factors for Cultivating Quality Cannabis

Modern cannabis cultivation requires persistence and creativity, especially since medicinal uses require precise methods. For consistency and productive buds, growers must combine numerous species under very particular growing conditions — whether in a controlled indoor environment or a greenhouse. Here are some of the factors they must consider:

Nutrition: Plants will need a balance of nitrogen, phosphorus, potassium, calcium, magnesium, and iron (and different amounts depending on the development stage).
Water: It must have the right pH and amount of nutrients. It should also be filtered and disinfected with a UV purification system.
Lighting: The right amount of light depends on whether your cannabis is in the vegetative or flowering stage. Too much light can damage plants.
Temperature: Ideal temperature ranges vary depending on the growth stage, and day vs. night. Higher temperatures require precise humidity regulation.
Humidity: The vegetative stage requires more humidity, while lower humidity is ideal during the flowering stage. As seen below, too much humidity can lead to mold growth.

Cannabis Cultivation Faces a Constant Battle Against Mold

While a moist habitat is necessary for growing plants of any kind, high humidity is lethal to successful cannabis cultivation. An overly moist environment promotes the outbreak of any number of plant-killing diseases. Two of the more prevalent culprits are the microorganisms Botrytis cinerea and Podosphaera macularis. You may know them by their more common names, Gray Mold and Powdery Mildew. The very mention of these molds causes cannabis growers to shudder, because they relentlessly attack their crop, cutting into their profits. Cannabis companies suffer substantial financial lossesopen_in_new due to these destructive fungi. One bad test sample may require entire batches to be discarded.

The beginnings of mold on a cannabis plant

Botrytis cinerea

Botrytis cinerea or gray mold manifests itself at first as a white growth but over time darkens to smoky gray, softening the plant as cells are destroyed. While it may develop anywhere in the natural world, it is frequently introduced into the sterile environment of a growing room as the spores latch onto the clothes of workers, who then unknowingly bring it into the facility. As overly humid air creates an environment perfectly suited for this mold to thrive, unsuspecting plants fall victim to the hungry microbe. Overly humid air creates an environment perfectly suited for this mold to thrive. Proper disinfection methods upon entering the cannabis cultivation facility would help counteract this frequent scenario. In addition, a 2012 studyopen_in_new demonstrated the susceptibility of Botrytis cinerea to UV-C disinfection.

Podosphaera macularis

Botrytis’ evil twin, Podosphaera macularis, thrives in places of overcrowded, over-watered plants and high humidity, adversely affecting the healthy growth of cannabis crops in indoor facilities and greenhouses. Young leaves of cannabis plants showing a white or grey powdery-fuzzy substance, small blisters on the top of leaves and a rotting smell are all clear indications that white powdery mold is on the attack. Once it has infected a plant’s leaves, it spreads easily to other areas of the plant. Infected buds become unusable. This relentless microorganism may attack at three different stages of cannabis cultivation: the vegetative stage, the flowering stage, and the drying/curing stage.

Aspergillus, Rhizopus, and Penicillium

During the drying phase, another group of molds (Aspergillus, Rhizopus, and Penicillium) take aim specifically at dead plants. While oven-dried plants suffer less mold than when air dried, the latter is preferred by consumers and boasts no negative effects.

Although [air filtration and chemical treatment] can be effective in combating microbial threats to cannabis production, the cleanest, most direct way of inactivating them is to use ultraviolet germicidal irradiation (UVGI).
—Engineered Systems Magazineopen_in_new

Drying phase molds (shown clockwise from top): Aspergillus Niger, Rhizopus stolonifer, and Penicillium

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Common treatments to help prevent mold at cannabis cultivation facilities

Within cultivation rooms and greenhouses, the best initial practice to thwart Gray mold and Powdery mildew is clean air circulationopen_in_new, which is a product of these essential practices:

Leaving adequate space between plants
Defoliating (removing dead leaves)
Regulating humidity to keep the air from becoming too saturated
Using circulation methods to increase airflow and air exchange

Fungicides are often used in an attempt to prevent these microbial intruders from infecting cannabis crops. However, these stubborn molds have developed immunityopen_in_new to various chemical treatments. Besides, this form of treatment can leave hazardous residues in its wake and incur repeated costs.

While the essential practices mentioned above are a good start in the war against gray mold and powdery mildew, there is another strategy that every cannabis cultivation facility could benefit from. Germicidal ultraviolet air and surface disinfection provides chemical-free inactivation of these molds.

Air & Surface Disinfection Systems to Improve Cannabis Cultivation

As long ago as 1890, UV-C treatment to render microorganisms inactive was discovered, tested, and ultimately accepted in the scientific community as viable. Throughout the 20^th century, the process has been perfected. UV disinfection is used to control bacteria, viruses, spores, fungi, and mold in air, on surfaces, and in water. Germicidal UV light, emitted at 254 nanometers over a certain amount of time, will attack and damage links in a microbe’s DNA chain, rendering it unable to replicate and suspending its proliferation. Read below how our UV disinfection models can be used to combat microbes in cannabis cultivation and drying rooms. Our Whitepaper PDFopen_in_new has additional product considerations, data, and UV-C doses needed.

Air Ducts

Air ducts, a known haven for mold, should be treated with UV disinfection. Our AeroLogic^® models easily install near the cooling coils (where spores are most likely to develop), treating them with UV light and rendering them inoperative before they spread throughout the building. Various models are available for your size duct or air handling unit. Our specialists can even customize a system for your setting.

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Circulation & Ventilation

Increased airflow and air exchange should be combined with UV treatment to help protect cannabis from disease-causing mold. Our Sanitaire^® UV-C Room Air Sanitizers are designed to fill those needs. Wall mounted, ceiling mounted, and mobile models are available.

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Directly on Surfaces

Work benches, seedling trays, surfaces, and tools should be directly disinfected with UV rays in labs and in between drying batches. Our Sanidyne^®, SaniLight^®, SaniRay^®, and SaniUV-Cube™ models will inactivate spores that may be transported and recirculated around the room by drying fans. Since these products have UV-C lamps exposed, rooms cannot be occupied during these treatments and plants should not be present.

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Direct UV air and surface sanitizers for cannabis cultivation

Water Disinfection

We know success in the cannabis industry involves the careful processes of growing and drying. But don’t forget to create the optimal conditions for your plants to thrive. Cultivate your cannabis with UV purified water to decrease the likelihood of diseased plants. Sanitron^® and MightyPure^® will provide your farm with the water flow requirements you need.

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