Professional Marijuana Grower March-April 2018 Issue

Feature Article by Eric Hopper Pathogen Control for Indoor and Outdoor Cannabis Plants T here isn’t much that is more disheartening than a pathogen attack on a flourishing marijuana garden. All cannabis cultivators will eventually encounter a pathogen in his or her garden. Fungi, bacteria, and viruses are all pathogens that can utterly damage a marijuana garden if left unchecked. Although fungi are the most common pathogens to cause headaches for cannabis growers, horticulturists need to be aware of all the potential threats to their gardens, how to properly prevent them from taking hold, and how to combat them when necessary. In most cases, the introduction of pathogens into the garden is preventable. Armed with a little knowledge, most grow- ers can prevent or rectify a problem before it becomes catastrophic. 26 • Professional Marijuana Grower Fungi The most common pathogens to affect cannabis crops are fungi. There are many different fungi that can affect cannabis, but the most common fungal pathogens found in a marijuana garden are pythium, powdery mildew, and botrytis. Pythium Pythium, the major contributor to root rot, is the most common root disease to plague the cannabis horticul- turist. This damaging, parasitic root fungus is capable of quickly spreading and destroying otherwise healthy crops. Pythium thrives in anaerobic conditions and dies off in well oxygenated conditions. Planting containers that stay saturated eventually become stagnant. This March/April 2018

Professional Marijuana Grower March-April 2018 Issue | Page 26