Tag Archives: powdery mildew

Keeping Your Environment Clean: Preventative Measures Against Contamination

By Jeff Scheir
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For years we have heard about and sometimes experienced, white powdery mildew when growing cannabis. It is a problem we can see, and we have numerous ways to combat it. But now more and more states are introducing regulatory testing on our harvests and they are looking for harmful substances like Escherichia coli., Aspergillis Fumigatus, Aspergillis terreus, …  just to name a few. Mycotoxins, mold and bacteria can render a harvest unusable and even unsellable- and you can’t see these problems with the naked eye. How much would it cost you to have to throw away an entire crop?

You bring in equipment to control the humidity. You treat the soil and create just the right amount of light to grow a superior product. You secure and protect the growing, harvesting, drying and production areas of your facility. You do everything you can to secure a superior yield… but do you?

Many of the organisms that can hurt our harvest are being multiplied, concentrated and introduced to the plants by the very equipment we use to control the growing environment. This happens inherently in HVAC equipment.

Your air conditioning equipment cools the air circulating around your harvest in a process that pulls moisture from the air and creates a perfect breeding ground in the wet cooling coil for growth of many of the organisms that can destroy your yield. As these organisms multiply and concentrate in the HVAC system, they then spew out into the very environment you are trying to protect at concentrated levels far greater than outside air. In effect, you are inoculating the very plants you need to keep safe from these toxins if you want to sell your product.

The cannabis industry is starting to take a page from the healthcare and food safety industries who have discovered the best way to mitigate these dangers is the installation of a proper UVC solution inside their air conditioning equipment.

Why? How does UVC help? What is UVC?

What is Ultraviolet?

Ultraviolet (UV) light is one form of electromagnetic energy produced naturally by the sun. UV is a spectrum of light just below the visible light and it is split into four distinct spectral areas – Vacuum UV or UVV (100 to 200 nm), UVC (200 to 280 nm), UVB (280 to 315 nm) and UVA (315 to 400 nm). UVA & UVB have been used in the industry to help promote growth of cannabis.

What is UVC (Ultraviolet C)?

The entire UV spectrum can kill or inactivate many microorganism species, preventing them from replicating. UVC energy at 253.7 nanometers provides the most germicidal effect. The application of UVC energy to inactivate microorganisms is also known as Germicidal Irradiation or UVGI.

UVC exposure inactivates microbial organisms such as mold, bacteria and viruses by altering the structure and the molecular bonds of their DNA (deoxyribonucleic acid). DNA is a “blue print” these organisms use to develop, function and reproduce. By destroying the organism’s ability to reproduce, it becomes harmless since it cannot colonize. After UVC exposure, the organism dies off leaving no offspring, and the population of the microorganism diminishes rapidly.

Ultraviolet germicidal lamps provide a much more powerful and concentrated effect of ultraviolet energy than can be found naturally. Germicidal UV provides a highly effective method of destroying microorganisms.

To better understand how Steril-Aire UVC works, it is important to understand the recommended design. Directed at a cooling coil and drain pan, UVC energy destroys surface biofilm, a gluey matrix of microorganisms that grows in the presence of moisture. Biofilm is prevalent in HVAC systems and leads to a host of indoor air quality (IAQ) and HVAC operational problems. UVC also destroys airborne viruses and bacteria that circulate through an HVAC system and feed out onto the crop. HVAC cooling coils are the largest reservoir and amplification device for microorganisms in any facility.

For the most effective microbial control, UV germicidal Emitters are installed on the supply side of the system, downstream from the cooling coil and above the drain pan. This location provides more effective biofilm and microbial control than in-duct UVC installations. By irradiating the contaminants at the source – the cooling coils and drain pans – UVC delivers simultaneous cleaning of surface microorganisms as well as destruction of airborne microorganisms and mycotoxins. Steril-Aire patented this installation configuration in 1998.

The recirculating air in HVAC systems create redundancy in exposing microorganisms and mycotoxins to UVC, ensuring multiple passes so the light energy is effective against large quantities of airborne mycotoxins and cleaning the air your plants live by.

Where are these mycotoxins coming from?

Aspergillus favors environments with ample oxygen and moisture. Most pre-harvest strategies to prevent these mycotoxins involve chemical treatment and are therefore not ideal for the cannabis industry.

Despite the lack of cannabis protocols and guidelines for reducing mycotoxin contamination, there are some basic practices that can be utilized from other agricultural groups that will help avoid the production of aflatoxins and ochratoxins.

When guidelines are applied correctly to the cannabis industry, the threat of aflatoxin and ochratoxin contamination can be significantly reduced. The place to start is a clean air environment.

Design to win

The design of indoor grow rooms for cannabis is critical to the control of airborne fungal spores and although most existing greenhouses allow for the ingress of fungal spores, experience has shown that they can be retrofitted with air filters, fans, and UVC systems to make them relatively free of these spores. Proper designs have shown clearly that:

  1. Prevention via air and surface disinfection using germicidal UVC is much better than chemical spot treatment on the surface of plants
  2. High levels of air changes per hour enhance UVC system performance in reducing airborne spores
  3. Cooling coil inner surfaces are a hidden reservoir of spores, a fertile breeding ground and constitute an ecosystem for a wide variety of molds. Continuous UVC surface decontamination of all coils should be the first system to be installed in greenhouses to reduce mildew outbreaks.

UVC can virtually eliminate airborne contaminants

Steril-Aire graphic 4

Steril-Aire was the first and is the market leader in using UVC light to eliminate mold and spores to ensure your product will not be ruined or test positive.

  1. Mold and spores grow in your air handler and are present in air entering your HVAC system.
  2. Steril-Aire UVC system installs quickly and easily in your existing system.
  3. The Steril-Aire UVC system destroys up to 99.999% of mold/spores.
  4. Plants are less likely to be affected by mold…with a low cost and no down time solution.

It’s time to protect your harvest before it gets sick. It’s time to be confident your yield will not test positive for the contaminants that will render it unusable. It’s time to win the testing battle. It’s time for a proper UVC solution to be incorporated throughout your facilities.

Soleil control panel

IoT & Environmental Controls: urban-gro Launches Soleil Technologies Portfolio

By Aaron G. Biros
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Soleil control panel

Back in November of 2017, urban-gro announced the development of their Soleil Technologies platform, the first technology line for cannabis growers utilizing Internet-of-Things (IoT). Today, urban-gro is announcing that line is now officially available.

Soleil control panel
Screenshot of the data you’d see on the Soleil control panel

The technology portfolio, aimed at larger, commercial-scale growers, is essentially a network of monitors, sensors and controls that give cultivators real-time data on things like temperature, humidity, light, barometric pressure and other key factors. The idea of using IoT and hypersensitive monitoring is not new to horticulture, food or agriculture, but this is certainly a very new development for the cannabis growing space.

sensor
Substrate sensors, used for monitoring Ph, soil moisture & electrical conductivity.

According to Brad Nattrass, chief executive officer and co-founder of urban-gro, it’s technology like this that’ll help growers control microclimates, helping them make the minor adjustments needed to ultimately improve yield and quality. “As ROI and optimized yields become increasingly important for commercial cultivators, the need for technologies that deliver rich granular data and real-time insights becomes critical,” says Nattrass. “With the ability to comprehensively sense, monitor, and control the microclimates throughout your facility in real-time, cultivators will be able to make proactive decisions to maximize yields.”

heat map
The heat map allows you to find problem microclimates throughout the grow space.

One of the more exciting aspects of this platform is the integration of sensors, and controls with automation. With the system monitoring and controlling fertigation, lighting and climate, it can detect when conditions are not ideal, which gives a cultivator valuable insights for directing pest management or HVAC decisions, according to Dan Droller, vice president of corporate development with urban-gro. “As we add more data, for example, adding alerts for when temperatures falls or humidity spikes can tell a grower to be on the lookout for powdery mildew,” says Droller. “We saw a corner of a bench get hot in the system’s monitoring, based on predefined alerts, which told us a bench fan was broken.” Hooking up a lot of these nodes and sensors with IoT and their platform allows the grower to get real-time monitoring on the entire operation, from anywhere with an Internet connection.

soleil visuals
Figures in the system, showing temperature/time, humidity/time and light voltage

Droller says using more and more sensors creates super high-density data, which translates to being able to see a problem quickly and regroup on the fly. “Cannabis growers need to maintain ideal conditions, usually they do that with a handful of sensors right now,” says Droller. “They get peace of mind based on two or three sensors sending data points back. Our technology scales to the plant and bench level, connecting all of the aggregate data in one automated system.”

In the future, urban-gro is anticipating this will lay the groundwork for using artificial intelligence to learn when controls need to be adjusted based on the monitoring. Droller hopes to see the data from environmental conditions mapped with yield and by strain type, which could allow for ultra-precise breeding based on environmental conditions. “As we add more and more data and develop the platform further, we can deliver some elements of AI in the future, with increased controls and more scientific data,” says Droller.

Applications for Tissue Culture in Cannabis Growing: Part 2

By Aaron G. Biros
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In the first part of this series, we introduced Dr. Hope Jones, who took her experience in tissue culture from NASA and brought it to the cannabis industry and C4 Laboratories. We discussed some of the essential concepts behind tissue culture and defined a few basic terms like micropropagation, totipotency, explants and cloning. Now let’s get into some of the issues with cloning from mother plants and the advantages that come with using tissue culture for propagating and cultivating cannabis.

Time & Resources

Dr. Hope Jones, chief scientific officer at C4 Labs

Taking cuttings from mother plants is arguably the most popular method of propagating cannabis plants. It is a process that requires significant real estate, resources and labor. “Moms can take up a great deal of space that is not contributing directly to production,” says Dr. Jones. “I know from experience that scaling up production and/or adding new strains to the production line requires significant time and resources to raise and maintain new healthy and productive mother plants.” Each mother plant produces a limited number of clones per harvest period and over the course of her life cycle.

By using tissue culture, a cultivator can generate an almost infinite number of clones from one plant cutting. With so many growers calculating their costs-per-square-foot, micropropagation is an effective tool to save space, labor and time, thus increasing profit margins. “Just to put it in perspective: Holly Scoggins’ book Plants From Test Tubes, cites a Day Lily cultivator who uses micropropagation to produce 1,000 plants in 30 square feet of shelf space each week,” says Dr. Jones. “Using conventional methods, one would need a half-acre to produce the same amount of plants.” Cultivators can produce a much greater number of plants-per-square-foot by using micropropagation effectively.

Damage from whiteflies, thrips and powdery mildew is all visible on this sick plant.

Early Health & Vigor

Most tissue culture methods use sterilized vessels that contain sugar-rich media to support growth of plantlets before they can photosynthesize on their own. “The media is prepped, poured into vessels, and placed in an autoclave (or pressure cooker) where it is subjected to high temps and pressure to achieve proper sterility.”

The sterile environment and rich growth media supplies plantlets with an abundance of everything they need. “When plantlets emerge from culture, they are pathogen-free, with a stockpile of food and nutrient reserves that support rapid growth and vigor, superior to conventional cuttings,” says Dr. Jones.

Stress & Disease

As any grower knows, mother plants can sometimes experience stress and disease. This might come in the form under or over-watering, heat stress, spider mites, whiteflies, mold and viruses. “Any stress or infection that a mother plant is subjected too can impact progeny health and productivity in a couple of ways,” says Dr. Jones.

Powdery mildew starts with white/grey spots seen on the upper leaves surface
Tobacco Mosaic Virus symptoms can include tip curling, blotching of leaf mosaic patterning, and stunting.

For example, diseases like powdery mildew and tobacco mosaic virus are often systemic, meaning that pathogens have spread to almost every tissue in the plant. Once infected, it is impossible to completely eliminate pathogens from tissues. Therefore any cuttings made from a diseased mother plant, even if they look perfectly healthy, will also be infected and can eventually present disease symptoms like reduced productivity and/or plant death, according to Dr. Jones.

How does tissue culture get around this problem? Remember that explants (small tissue samples used as starting material) can be extracted from any part of the plant. Meristematic cells in shoot tips and leaves are the source of new plant growth. Dr. Jones explains that these cells, and the first set of primordial leaves are not connected directly to the vascular tissue, the plant’s transport system by which pathogens spread. Therefore, meristematic cells tend to be disease-free, whatever the condition of the mother. It takes a sharp blade, a dissecting microscope, and a lot of experience to learn, but as Dr. Jones explains, “harvesting explants from meristems is a routine micropropagation technique used by ‘Big Horticulture.’ One example is the strawberry. Viruses and pathogens are so prevalent that the strawberry industry must use meristematic culture to ensure pathogen free progeny.”

Epigenetics

Now let’s talk about epigenetics. We know that plants don’t have the option of physically moving away from stress or predation. Instead, they have evolved sophisticated ways of changing their own biology to adapt to and/or protect themselves. “Consider what happens to a mom exposed to a pathogen. The infected plant will start expressing (turning on) genes and making proteins that contribute to pathogen resistance,” says Dr. Jones. “These changes to gene expression are partly regulated by epigenetic modifications, chemical changes to DNA that increase or decrease the likelihood a cell will express a particular gene, but that do not actually modify the gene itself. Like annotations to a piece of music, epigenetic modifications don’t change the notes but rather how loud or soft, quickly or slowly the notes are played.”

There are more than 1,000 different viruses and mixed infections are very common

This is where it gets interesting. “Epigenetic modifications can be systemic and long lived. Plants infected by a pathogen or stressed by drought will present widespread epigenetic modifications to their DNA,” says Dr. Jones. “For an annual plant like cannabis, those modifications are relatively permanent. Thus a cutting from a mom having drought or pathogen adapted epigenetic programming will inherit that modified DNA and behave as if it were experiencing that stress, whether present or not.”

In the wild, this adaptability is critical for plant survival and reproduction, but to a grower, this is a less-than-ideal scenario. “The epigenetic modifications allowed the mother to tolerate the stress, which is great from the perspective of survival and fitness, but it comes at a cost. Some of the finite energy and resources that usually support plant growth and reproduction are instead channeled to stress response,” says Dr. Jones. This trade off results in reduction in overall plant yield and quality. “Those epigenetic changes result in a new phenotype for that mother,” says Dr. Jones. “All cuttings from her will reflect the new phenotype. This is one major mechanism underlying what many in the cannabis industry (incorrectly) call ‘genetic drift,’ or the loss of vigor over successive clonal generations.”

This is again where tissue culture can be such a game changer. The process of dedifferentiation, as explained in part 1 of this series, can rejuvenate a “tired” mother plant by inducing a kind of reboot– clearing accumulated epigenetic modifications that negatively impact progeny vigor and productivity. In the third part of this series, we will discuss the five stages of micropropagation, detailing the process of how you can grow plantlets in tissue culture. Stay tuned for more!

durnagofacility

Solutions for Cannabis Cultivation: Integrated Pest Management

By Aaron G. Biros
3 Comments
durnagofacility

Pest problems in cultivating cannabis such as spider mites and powdery mildew are major concerns facing growers on a daily basis. Colorado’s ongoing recalls for cannabis products containing pesticides serve as a reminder that pest problems continue to plague growers. Utilizing integrated pest management (IPM) can help reduce the need to use any pesticides, as well as mitigate the risk of unwanted pests wreaking havoc on a cannabis harvest. urban-gro, a solutions provider for commercial cannabis cultivation, builds IPM plans for large-scale cannabis growers tailored to meet specific needs in regulatory compliance for different states.

durnagofacility
urban-gro helped design this facility in Durango, Colorado.

Biological controls are essential to any proper IPM solution for growers. Beneficial living organisms such as insects, mites, nematodes or entomopathogenic fungi can all be applied as a method for controlling pests. Biological controls like those can reduce the need to use pesticides on cannabis. John Chandler, vice president of cultivation technologies at urban-gro, believes IPM requires a broad, systematic approach to eliminate the need for pesticides. “IPM is a combination of cultural, chemical and biological control,” says Chandler. “We start by evaluating the air flow of the facility, how plants are transported, any exclusion barriers and air filtration.” A robust IPM plan begins in the design phase of a new facility. “We can make key adjustments in floor plans, layouts and mechanical systems to optimize that first line of defense that is critical to mitigating the risk of pest issues.” Incorporating good agricultural practices can also help mitigate those risks.

durangopot
A close-up of a plant entering flowering at the Durango facility

“We help develop standard operating procedures with good agricultural practices in mind, including preventing cross contamination, which is the biggest pest issue facing cannabis growers,” says Chandler. “I encourage clients to set up harvest and vegetative rooms so that the plants are moving in one specific direction between rooms rather than back and forth.” Using positive air pressure with proper ventilation can further prevent cross contamination. Chandler also recommends scrubbing air coming into the building with gaseous hydrogen peroxide to keep filtering air in ventilation.

urban-gro
IPM plans require thinking in terms of systems to find the right balance of biological controls.

According to Mark Doherty, director of sales at urban-gro, their IPM plans are customized to meet different states’ rules and regulations, including each list of approved pesticides. “We work to design a system that meets each individual grower’s needs, while helping them navigate regulations in any given state,” says Doherty. “It is important to make cannabis safe for patients and IPM is critical in building a healthy ecosystem for plants to be grown in a safe, yet cost-effective manner.” Proper use of IPM can reduce the need to use pesticides, which could impact a cultivator’s bottom line, but ultimately protect patients’ wellbeing by providing safe and pesticide-free cannabis.

prosodic
Procidic works on contact and with residual action.

When all else fails and pests still find their way onto cannabis, there is a solution to address major losses. urban-gro distributes a product called Procidic2®, a broad-spectrum bactericide and fungicide compound, manufactured by Greenspire Global. The advanced commercial formula is designed to eliminate pathogenic bacteria and fungi. Procidic2® can be applied as a preventive and a curative. WSDA Organic Program has approved Procidic2® for use in organic agriculture production and handling. According to Steve Knauss, president of Greenspire Global, “Procidic2® works in sync with the plant through two modes of action: First it controls powdery mildew and gray mold on contact, and secondly it is absorbed systemically into the plant to control disease infection such as root rot,” says Knauss.

Implementing a comprehensive IPM system requires making key changes in cultural, biological and chemical controls. In doing so, growers can successfully mitigate the risk of pest problems, thus reducing the need for potentially harmful pesticides.