Marijuana Business Magazine July 2019

Marijuana Business Magazine | July 2019 134 Cannabis growers who want to prevent microbials, including mold and powdery mildew, have several strategies they can employ, such as: • Ensuring visitors to the facility don’t bring along any unwanted visitors by requiring a change of clothes, protective garments—or even in- stalling a room with special blowers to remove pests. • Managing the temperature, humidity and air circulation to keep your grow room environment from becoming a breeding ground for undesirable microorganisms. • Employing growing practices that strengthen your plants’ immune systems, so they can fend for themselves. • Quick response in the event of an outbreak to safeguard against losing the entire crop. within the plant and around the buds themselves, that’s where you run the risk (of microbial growth.)” To Lambert, the danger zone in a grow room is 65% relative humidity or above. “All it takes is a certain level of moisture at the right ambient tem- perature for something to kick off,” he said. At AlpinStash, Murr-Sloat likes to keep his plants at roughly 82-83 degrees Fahrenheit during the day and tries to avoid large drops in temperature at night. “That makes your plants espe- cially susceptible to mold,” he said. “Mold tends to germinate in cooler temperatures.” While Murr-Sloat only drops the temperature to around 78 degrees at night, other grows might cool their rooms by up to 20 degrees. As plants age through the life cycle, he gradually steps down the relative humidity until it’s around 35% at harvest time. In Toronto, Krytiuk keeps his relative humidity levels between 50% and 65%. But the most important factor to him is having an adequate HVAC system and proper supplemental fans. “I’m a firm believer in airflow,” he said. “I like a lot of oscillating fans inside the room.” Plant Health and Spacing Growers should be cognizant of giving their plants enough space to lessen the opportunity for microbial growth. Pathogens can fester where leaves and branches overlap. “We definitely avoid overcrowding,” Murr-Sloat said. “Every cola (flower cluster) and every branch needs breathing room.” Murr-Sloat said cultivators shouldn’t be afraid to cull strains that easily succumb to microbial outbreak under the conditions of their grow. “If we had any cultivar that’s sus- ceptible, we’d get rid of it,” he added. Keeping your plants as healthy as possible is one of the best defenses against pathogens. Murr-Sloat likes to create his own living soil with beneficial fungus, bacteria and insect frass to create strong, robust cannabis. He also watches for nitrogen toxicity, a common problem in marijuana, where the leaves take on a dark-green color. Once cannabis plants have developed the toxicity, they’ll be more prone to a microbial outbreak. Correctly pruning plants can also have a big impact on airflow and, therefore, on keeping out microbials. Krytiuk adheres to the practice of “lollypopping” his plants, where up until the second week of flowering all the plant material aside from the stalk is removed. “Clipping that out and opening up the plant allows better airflow,” he said. Lance Lambert leads Bovedaʼs herbal division. Courtesy Photo Best Practices In Cultivation | Bart Schaneman Properly arranging your plants to promote air flow is one step in preventing mold and microbials from taking hold in your grow room. Courtesy Photo