Ampelomyces Quisqualis
These are naturally occurring hyperparasites of powdery mildew. They form colonies on the infection, reducing growth and may eventually kill powdery mildew on cannabis leaves. Rain perpetuates the life cycle of this beneficial fungus. A formulated powder is available under the brand name AQ-10.
Bacillus Pumilus
Bacillus Pumilus is a spore-bearing bacterium found in soil. It is resistant to environmental stresses, include UV light. The growth of Bacillus Pumilus on plant roots prevents Fusarium spores from germinating. A commercial product is available by the name of Sonata. Application boosts the cannabis plants’ immune system, inhibiting fungal germination and growth.
Potassium Bicarbonate
Potassium bicarbonate is a water soluble compound often used to neutralize acidic soil in crops. It is now under consideration as an organic fungicide. Potassium bicarbonate is a synthetic compound resultant of a combination of potassium carbonate, carbon dioxide and water and is found naturally in virtually all life forms. It is most seen in crystal form or as a soft, powdery substance.
Potassium bicarbonate is an effective defense against powdery mildew, Septoria leaf spot, blight and many other fungal diseases. To apply, mix three tablespoons potassium bicarbonate, three tablespoons oil and one half teaspoon castile soap with one gallon water. Pour mixture into a spray bottle and mist the cannabis leaves. (This also works on most edible plants).
Potassium bicarbonate can be purchased from garden centers, hardware stores and pharmacies, or can be obtained online under various brand names.
Silica and Silicate Salts
When silica is added to the soil, it provides a strengthening agent for plant cells; it facilitates thicker cell walls, which results in stronger stems. The availability of silica to a plant’s roots provides a protective barrier, dissuading fungal reach into the inner workings of the plant’s ability to uptake nutrients. The plant becomes more capable of surviving stress once clad with the armor silica provides. In addition, enhancing the soil with silica containing materials help to keep it aerated, allowing free flow of oxygen. This is good news for Mary Jane and her counterparts!
Hydroponic environments can also benefit from the addition of soluble silicon added to the water solution. The roots become stronger and healthier, resulting in increased yields. The addition of silica in either growing situation has proven to reduce the occurrence of powdery mildew.
Several forms of silica are available for soil or water growing media:
• Syna-Gro Po-Tekt, a potassium silicate solution, can be used in the soil, hydroponic systems and as a foliar spray.
• Pyrophyllite clay, and aluminum silicate in powder form, can be applied as a dust or foliar spray.
• Silica stone is used in hydroponic systems and can be re-used after a thorough cleaning.
• Greensand can be added to the soil to enhance the benefits of silica.
• Vermiculite and perlite is available at garden centers. Mix it into the soil. Many potting soils come with the amendments already added.
• Diatomaceous earth contains the shells of marine microorganisms. This amendment also serves as a control for soft organisms such as slugs, as the tiny shells pierce their skin causing dehydration through the loss of body fluids.
Sulfur
Fungi cannot make their own food therefore they depend on your beloved Mary Jane (and other foliage) for food. Consider them the vampires of the plant world. When they appear there should be one goal in mind: attack and retreat!
Sulfur can lower the pH level of highly alkaline soils and is also used as a treatment for powdery mildew, gray mold and Septoria. If using as a foliar spray, test it on a few branches and wait a couple of days before applying, as sulfur can cause leaf damage if not applied properly. Sprinkle sulfur dust on the infected plants, but follow directions carefully. Sulfur can be applied as a dust or foliar spray. Sulfur in both liquid and powder form is available at most garden centers.
