CEA Tech Tips

Punch Out Powdery Mildew On Cannabis

Powdery mildew (PM) is made up of many fungal pathogen species that attack and thrive off healthy, living plant tissue. Golovinomyces sp. (aka Erysiphe sp.) is the most common PM species that growers find on cannabis today. We recognize PM as producing a distinctive white sporulation on the foliage that looks like powdered sugar. Without proper management through chemical and cultural practices, this pathogen can quickly spread throughout your operation and decrease crop quality.

Powdery mildew forms white spores on the surface of the foliage.
Conditions ideal for PM proliferation include moderate temperatures, dry leaf surfaces, and high humidity. Unfortunately, the optimal temperatures for PM go hand-in-hand with the ideal temperatures for cannabis production and keeping a dry leaf surface is needed to prevent other diseases such as Botrytis from developing. Thus, growers should prioritize the management of their relative humidity levels to prevent PM. A constant humidity level of 55-60% in the canopy (65-75% if using predatory mites) is preferable to excessively high humidity (>85%). Growers can maintain adequate humidity within the plant canopy with appropriate HVAC equipment in conjunction with horizontal airflow fans (HAF) or vertical airflow fans (VAF).

Powdery mildew should not be mistaken for trichome production
As for all diseases, sanitation is key to prevention, and it is important to sanitize your production
areas between crops. Following physical removal of debris, the first step is to clean all hard surfaces using a cleaning product such as Strip-It (for greenhouses) or Horti-Klor (for warehouses)*. Once surfaces have been cleaned, use a sanitizing agent such as KleenGrow (rinse direct crop contact surfaces with potable water), ZeroTol 2.0 or SaniDate 5.0 for disinfection purposes*. It is critical to ensure that all cuttings and clones coming into a new production area are free of disease. Immediately remove any infected foliage and dispose of it properly. Replace gloves and other protective equipment after handling infected material. Work in infected areas late in the day and avoid staff moving back into clean areas from infected areas.

EPA registered and 25(b) products need to be approved for use on cannabis by the regulatory agency in the state in which the product would be used. When using biofungicides, best practices call for application of ZeroTol 2.0 before Cease or Triathlon BA to destroy surface spores of the pathogen on contact while the biofungicide protects uninfected tissue. Contact your Griffin sales person or GGSPro for product rates and application intervals.

Product NameItem Number
25(b) Products
Procidic 2
EPA Registered Products
Regalia CG
SaniDate 5.0
Strip-It Pro
Triathlon BA
ZeroTol 2.0

*Check state approval status for these products.
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Getting More From Your Cleaners and Sanitizers With Foam

All food and medicinal crop growers take great care to keep their production spaces clean. Often, this process involves a full sanitation protocol for the production space at the end of a crop cycle to reduce the risk of carryover pests and pathogens. The complete process involves four steps: Physical cleaning (remove the debris), chemical cleaning, rinsing with clear water and sanitizing.

It’s important to include the physical and chemical cleaning steps in the process prior to sanitizing. Favorite sanitizers, including ZeroTol 2.0, SaniDate 5.0 and Kleengrow, treat the surfaces they contact. If the surface is dirty, the sanitizers will treat the debris, but not penetrate to the surface below. If the sanitizer can’t contact the surface, the surface can’t get clean!

We can all increase the efficacy of our cleaners and sanitizers by utilizing the power of foam. Foaming makes the application more effective by increasing coverage and contact time. Foams also make it a lot easier to see where treatments have been applied.

Griffin offers two great foamers from Dramm to get this job done. With both small and large volume options, growers can have the right tools for all needs, from large greenhouses spaces to smaller warehouse production rooms. The Foam8L is a 5 liter compression foamer that is highly portable and great for small spaces. Expect to treat 400-500 sq ft from one full tank. For larger spaces, turn to the FM20-30 foamer. This cart unit has a 20 gallon tank, a 30 foot hose and runs on compressed air*. Both products are compatible with popular cleaners and sanitizers.

 Ask your Griffin sales person for a bulletin outlining GGSPro’s recommendations for hard surface sanitation for food and medicinal crops. Your sales person can help you choose the right cleaner and sanitizer for your situation and will let you know if you need to add a foaming agent to the tank

Dramm Compression Foamer 8L Tank - $157.59

Dramm Compression Foamer 8L Tank - $157.59
No 74-2688

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Dramm Foamer FM 20-30 Aire Powered 20gal Tank - $1,485.26

Dramm Foamer FM 20-30 Aire Powered 20gal Tank - $1,485.26
No 74-2689

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*Compressed air source required for the FM20-30 Foamer
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Boosting Root Development in Cannabis Crops

Cannabis growers are a diverse group. Some grow hemp, others grow marijuana. Some produce organic crops, others use conventional products. But, all cannabis growers have one thing in common: They need healthy roots as quickly as possible.

Proper moisture management is the key to good root growth. Early in propagation, maintain high humidity around seeds and cuttings without adding moisture to the media, which should be wet but not saturated. As roots develop, careful irrigation maintains even media in the wet to moist state. Once roots reach the bottom of the cells, allow the media to dry to the lower end of moist, widening the moisture cycle as the roots continue to develop. Media should never be allowed to reach a dry stage during propagation.

Essential Plus 1-0-1
To boost root development, Griffin’s GGSPro technical team encourages cannabis growers to utilize Essential 1-0-1. Essential 1-0-1 is a liquid, nutritional supplement containing humic acid, yucca (natural wetting agent) and amino acids in a solution with a very low nutritional charge. This OMRI-listed, organic product has no pesticidal activity or claims, which means it is universally acceptable for use on cannabis. Essential 1-0-1 has a proven track record of speeding and increasing root growth in a wide variety of crops, and we are seeing the same thing in cannabis. Cultivators report stronger root growth and positive impacts on secondary compounds. Apply once as roots start to develop in propagation and again at transplant at 32 oz/100 gal. Many growers realized benefits when repeating application every four weeks throughout the crop. Essential 1-0-1 is compatible with most water-soluble fertilizers, which means you can blend it in your concentrated stock tanks and inject right along with your fertilizer. Or, mix it at final rate in your batch reservoirs.

Add Essential 1-0-1 to your SOP, watch your moisture levels and build roots more quickly for ongoing crop health.


Featured products

Essential Plus 1-0-1 2.5 gal

Essential Plus 1-0-1 2.5 gal
No 160004GR

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Essential Plus 1-0-2 30 gal

Essential Plus 1-0-2 30 gal
No 166001GR

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Essential Plus 1-0-3 1 gal

Essential Plus 1-0-3 1 gal
No 166002GR

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Essential Plus 1-0-4 1 qt

Essential Plus 1-0-4 1 qt
No 166003GR

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Planning to purchase a larger number of containers of Essential 1-0-1? Ask about volume discounts.
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Hemp Russet Mites: Scouting and Control Tips

Hemp Russet Mite (HRM) is an eriophyid mite that can severely damage flowers and decrease THC and CBD in cannabis production. Eriophyid mites are small, cigar-shaped pests; they’re capable of reproducing profusely. They infest many horticultural crops.

The eriophyid mite that occurs in cannabis is called Aculops cannabicola. It’s known to occur on cannabis, as well as hops and hackberry.

HRM can infest indoor production facilities throughout the year. These mites are carried on incoming plant material, on staff and tools. They can also move readily on wind currents.

Hemp Russet Mites on cannabis

HRM scouting tips

HRM detection should be part of the weekly scouting protocol that goes with yellow sticky card and whole-plant inspections. HRM should be addressed as quickly as possible.

When scouting, growers should look for leaf curling and carefully inspect leaves with a 20X hand lens or greater magnification. Scout crop edges and, since HRM are known to spread on wind currents, look near fans, too.

Inward leaf curling is another sign of infestation. If leaf curling is observed, sample the leaves and look in the nooks and crannies of the leaves for HRM.

HRM control options

Control options in cannabis are limited. Beneficial insects are a great option for early HRM infestations, but they’re not known to completely eradicate HRM populations. Release BCAs preventively for best control of HRM.

Horticultural oil sprays are effective at reducing populations. Applicators must read and follow the label instructions, and also follow all state and local regulations regarding chemical application to cannabis crops. All products listed below may not be approved for use in all states. Products other than those listed may be safe, effective and legal.


Featured products

Product Name
Item Number
Ecotec Plus 17%
2.5 gal, OMRI-listed
SuffOil-X Spray Oil 80%
2.5 gal, OMRI-listed
Amblyseius andersoni
62,500 BI 250 mini sachets w/hook
Amblyseius andersoni
Mini sachets on sticks, 1000/CS
Anderline aa
A. andersoni, 125K 5 liter bag SB
Anderline aa
A. andersoni 200 mini sachets SB
Amblyline cal
A californicus 200 mini sachets w/hooks SB
Amblyseius californicus, 2000/bottle SB

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