Most of Colorado’s Failed Cannabis Tests Stem from Microbials

Excerpts from an annual report from the Marijuana Enforcement Division revealed that nearly 15% of cannabis flower and trim failed microbial testing last year.

“A growing percentage of cannabis is failing microbial testing in Colorado, and the problem could be stemming from easily overlooked issues in growers’ cultivation facilities, according to Carly Bader, a microbiology analyst for AgriScience Labs, one of the first state-licensed testing facilities.

An annual report from Colorado’s Marijuana Enforcement Division recently revealed that 86.35% of adult-use cannabis flower and trim, as well as 87.30% of medical cannabis flower and trim, passed microbial testing in 2019, meaning that nearly 15% failed for concentrations of yeast and mold that are over the legal limit.

Pamela Reach, CEO of Rare Dankness, a vertically integrated cannabis operator in Colorado, says microbial issues are not unusual for cannabis crops in the spring, when the transition from cold, dry, wintery conditions into warmer weather creates optimal conditions for powdery mildew.

Link to the article by Cannabis Business Times.

Can CO2 be used to stop the spread of powdery mildew?

No and....Yes. If you are supplementing your plants with CO2 by atmospheric enrichment, i.e. CO2 gassing, then NO, CO2 will not slow the spread of powdery mildew. While you will achieve faster and bigger growth, you may lose a significant portion of your crops through powdery mildew.

However, if you supplement your plants with CO2 using an aqueous CO2 mist, then YES, you will significantly slow the spread of powdery mildew and save your crops.

CO2 Delivery Solutions™ provides CO2 to your plants by misting an aqueous CO2 solution directly on to your plant. The system completely dissolves and saturates CO2 in water creating the aqueous CO2 solution. The CO2 solution is misted on to the plants from an overhead misting system. The mist forms a thin film of aqueous CO2 on the leaf surface, isolating the leaf from the atmosphere. This creates a diffusion gradient which favors the transfer of CO2 into the leaf – through the entire leaf surface, not just the stomata as in the case of CO2 in the air – where the CO2 is used for photosynthesis. Studies on various plants have shown growth enhancement equal to that of CO2 gassing, using a fraction of the CO2 gas versus CO2 gassing resulting in significant CO2 cost savings. But there is one other key difference.

Perimeter Protection™

The aqueous CO2 solution is acidic, with a pH of 4.5 - 5. Therefore, when the solution is misted on the plant, the pH on the plant surface drops. Once the CO2 transfers into the leaf (within a couple of minutes), the pH bounces back towards neutral. We recommend misting for 5 to 15 seconds every 15 to 20 minutes during the light cycle for photosynthesis, and all day & night if you are concerned about powdery mildew spread. This fluctuation in pH occurring three to four times an hour creates an unfavorable environment for epiphytic microbial pathogens such as powdery mildew and E. coli to multiply and spread. We call this phenomenon Perimeter Protection™.

While it is counter-intuitive for most growers, especially Cannabis growers, to mist their plants, the key difference is the pH of the solution. Misting regular water may indeed be a bad idea and may contribute to promoting the spread of powdery mildew. However, aqueous CO2 is a safe, reliable and easy to apply solution to slow the spread of mold and powdery mildew, while providing more CO2 for enhanced photosynthesis and growth.

Robert Allen, owner of two greenhouses at Sacred Seeds Hemp Farms in Missouri growing hemp for hemp seeds, explains why he is using CO2 Delivery Solutions™, "I am using CO2 Delivery Solutions™ primarily to help prevent the growth of mold and powdery mildew, but let's face it, faster growth and larger plants were huge selling points as well. As of April I have been using the system in two large greenhouses for about a month and I am already seeing improved growth with no signs of stress, mold or mildew."

For more information on the science behind Perimeter Protection™, please read this previous article featuring Dr. Matt Julius entitled “Understanding Cannabis Pathogens with Dr. Matt Julius” and watch this video.

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