"High humidity (over 50%) and grow environment contamination should be eliminated. Grow mediums should be sterilized and then treated with beneficial fungi (such as Trichoderma and Gliocladium) and beneficial bacteria.
Light intensity should be adequate for penetration deep into plant canopy, both vertical and horizontal. Plants should be directly in line of fans and other aeration. In-line charcoal filters and other traps should be in place on all air intakes. Strict sanitation controls should be in place for anyone who enters a grow environment.
"Bourdeaux mixture" can be useful for controlling gray mold. A spray containing copper, Bourdeaux mixture, and a beneficial organism called Bacillus subtilis is effective against downy mildew. Spraying with bicarbonate of soda, organic horticultural oils, and sulfur can kill powdery mildew. Some growers use sulfur burners to create airborne sulfur treatment against powdery mildew. Bacteria can be controlled using Bourdeaux mixture.
Viruses are impossible to kill once they have infected a plant. A preventive measure to protect against viruses, other than the generic tactic of preventing them from entering grow environments, is to keep plants' immune systems healthy with proper watering, temperature, root zones, and nutrients.
If molds, fungi, viruses or bacteria take hold in a grow environment, it may be necessary to remove affected plants completely. Near-harvest buds affected by most insects, pathogens and diseases can be partially salvaged by using them to make water hash. Otherwise, all plants or plant parts affected must be immediately removed and destroyed, and any tools, clothing, or other materials that came in contact with the affected plants must be removed, sterilized or destroyed.
Please note that smoking or handling whole marijuana infected by molds, mildews, and fungi can cause serious human health problems."
