Tag Archives: IPM

Building An Integrated Pest Management Plan – Part 5

By Phil Gibson
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This is the fifth in a series of articles designed to introduce an integrated pest management framework for cannabis cultivation facilities. To see Part One, an overview of the plan and pest identification, click here. For Part Two, on pest monitoring and record keeping, click here. For Part Three, on preventative measures, click here. For Part Four, control methods, click here. Our final chapter, Part Six, discussing emergency response, comes out next week to wrap it all up.

This is Part 5: Pest Control – Taking Action

Previous chapters have covered the many preparations you can take to protect your facilities from pest attacks and outbreaks before they get started. This chapter will summarize the concepts of pest control thresholds and the actions you can take for the painful event when you surpass those limits (and various examples). The Integrated Pest Management (IPM) recommendations provide you with a framework for these plans.

Figure 1: Cleaning regimen, the heart of successful operations – no biofilm buildups

Preventative actions are part of your regular site operations; in other words, they are how you avoid problems before they happen. Just to hit this action one more time: cleaning must be fundamental to your facility. Water sanitation and changing filters must be done on schedule and frequently to avoid biofilm build up and nasty self-multiplying eco-systems.

For each of the rooms in your facility, identify the acceptable tolerance level for each type of pest that you may encounter. Define the intervention levels per room: preventative, direct action and escalated direct action. Follow your predefined procedures and defend your facility. Let’s cover high, medium and low tolerance example responses.

High Threshold for Tolerance

For example, the impact on your plants, your profits and your yields from the discovery of a white fly fluttering inside of one of your flower rooms may be very small. If this presence is late in your harvest cycle, your tolerance of this discovery may be very high. Your team could take preventative actions to clean the room more aggressively or to check your traps more frequently, but you are probably not going to want to invest in aggressive actions at that time in the harvest cycle.

Move from passive observation to the shake test. With sticky traps in place, shake or brush your plants. Do you see the bug counts increase on your test sheets?

Figure 2: Thrip Evidence c/o UC ANR Publication 7429

As that infestation grows, you may set a threshold for direct action (i.e. 5-10 flies per trap per week). If you reach that level, implement a treatment action with a non-chemical microbial biofungicide to stop growth in the roots or neem oil as a direct chemical action.

When you reach your escalated threshold of 10-20 flies per trap or direct plant damage is apparent, an infestation is more serious. In that event, you may choose to take steps to directly reduce the pest population with knock down sprays of approved direct chemical pesticides like citric acid or insecticidal soaps. Be sure to use your Personal Protective Equipment (PPE) for breathing and contact safety if you get into this situation.

Medium Threshold for Tolerance

Depending on the timing in your harvest cycle, the discovery of fungus gnats in your grow room may trigger a medium level alarm for you. Is the location, a small example with a minimal frequency? Is this addressable with additional attention to cleaning the area and longer dry periods in the irrigation or is this the beginnings of an infestation? Fungus gnats feed off of fungus or organic matter in soil triggered from an overly moist root environment. You may choose to react with immediate cleaning at the first existence in a room. Or you could set your “Medium” level alert status to be additional sticky trap distribution at the first visible gnat. If those counts reach 10-20 gnats per sticky trap per week, begin your foliar spray regimen with Zerotol or the equivalent.

Figure 3: Fungus Gnats

If these counts do not respond to your treatment, meaning that the next sticky trap count reaches beyond 20+ gnats per trap or visible direct plant damage, then institute your root drench protocol with a solution of BActive 1-2 times per week until the problem is under control and the counts are reduced. If the growth continues, look to approved pesticides in your area (as an example, AzaGuard Asadirectin).

Low Threshold for Tolerance

Alternatively, you may have a unified air circulation system due to facility limitations. Your air circulation may be shared across all of your mother plants, clones, veg and flowering plant areas. In that case, any presence of an airborne fungal infection like powdery mildew would have a very low tolerance of acceptance. Selective de-leafing of the infection and increased airflow are your first defense. Any visible presence beyond that would trigger a low threshold alert and immediately start a preventative action, such as carefully removing the infected plant material much wider than a few leaves and treating the area with foliar sprays like Zerotol (hydrogen peroxide plus).

If the penetration continues or expands, treatment would escalate to minimal risk pesticide follow up and observation. Chemical oils or citric acid might be in your mix in this case.

Figure 4: Powdery mildew in cannabis – Ryan Douglas Cultivation LLC

Finally, if repetitive treatments once a week are not turning the tide, increasing to once per day or even once per ON/OFF lighting cycle until the infection is controlled. At this point, you may decide to strip the room down and start over. Clearly the choice to “throw in the towel” is a total loss of the crop, but it may be the best option relative to minimal yields and failed flowers that will not sell.

Pest Control Actions

Our Integrated Pest Management recommendations paper gives you examples of what to consider for plans with white flies, fungus gnats, root aphids, powdery mildew and biofilm on plumbing or surfaces. These follow the preventative action, direct action, escalated direct action and pesticide approaches for each example. These are options to plan for water sources, root treatment, tunneling, crawling and flying phases.

In summary this week

As covered, preventative measures are your best defense. Hire expert consultants and plan these well. Escalate your response based on your scouting activity and your plan. Add your sticky traps, de-leafing, root drench, foliar sprays or knock down sprays as defined by your pest population control actions document.

For more detail on each of these treatments, you can see examples for your integrated pest management procedures in our complete white paper for Integrated Pest Management Recommendations, download the document here.

In our final chapter, Emergency Response, we will review control thresholds and example plans for a range of problems from biofilm build up to white flies and more.

Our final chapter after will describe emergency response framework and reviewing your complete plans. See you next week.

Building An Integrated Pest Management Plan – Part 4

By Phil Gibson
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This is the fourth in a series of articles designed to introduce an integrated pest management framework for cannabis cultivation facilities. To see Part One, an overview of the plan and pest identification, click here. For Part Two, on pest monitoring and record keeping, click here. For Part Three, on preventative measures, click here. Part Five comes out next week on how to build a framework for control actions and how to monitor them. More to come!

This is Part 4: Direct Control Options

Even when the best methods are implemented and precautions are taken to protect your infrastructure, determined pests can penetrate your perimeter. Before you see crawling, hopping or flying insects, or sickly-looking plants, be sure to implement your physical protection (positive pressure airflow sealed facilities) and personal hygiene methods (shoe baths, sticky mats, & air shower entrances) to protect your crops. Equip your employees with personal protection equipment (PPE) proper gloves, masks and clothing as discussed in our last chapter, preventative measures.

Figure 1: Fungus Gnats Unleashed In A Grow Room

When things do break-out beyond your acceptable thresholds, Direct Control Options include non-chemical microbial biofungicides, microbial bioinsecticides and direct chemical control options. Lots of big scary words there, all of which are toxic even under safe application methods and when used at recommended concentrations levels. This means training in their use and protective clothing is required. Careful application of these control options is necessary so you exterminate your pests and not your people! This seems obvious, but do not just “wing it.”

These chemical elements can be applied in diluted concentration levels, manual wipe-down application, concentrated flush frequencies, or root drench applications, foliar spray mist applications, HVAC aerial diffusions and aerial knock-down sprays. You may even choose to remove badly infected plants and destroy them completely.

Use experts when you are planning for these tools. All of these methods require handling and safety precautions. Proper breathing filters, eye & skin protection, as well as disposable gowns/hazmat suits should be used when applications are performed and until the applications have dissipated to safe levels. Be careful not to co-mingle removed plant materials. Gloves become transport and infection spreaders after use.

Please also be sure to review your harvest testing requirements and what treatments are safe for your consumers and within legal limits. No one wants to have their harvest rejected due to pesticide contamination.

Figure 2: Municipal Water Treatment, RAIR Cannabis, Michigan

Clean-up after application may be required depending on the bioinsecticide or chemical that is used. Again, always ensure the safety of your employees and take precautions.

Start the application of your control options with your site map, room assignments and scout monitoring teams. Where does air flow into and within the facility? When your scouting team count logs go beyond your acceptable thresholds, here are some options for you.

Let’s begin with cleaning your irrigation and nutrient water sources. For a walk-through tutorial for incoming water treatment, humidity recovery and nutrient water recycling, please review the video tour of Water Treatment at RAIR Cannabis to see how an expert has done it.

From the IPM Planning Guide standpoint, peroxide and acid sterilizers can be used to clear irrigation water, for surface wipe-downs or as direct plant applications. We will cover those first. Caustic sterilizers require PPE for cleaning. Forgive my image here, we were just using water.

Concentrated Cleaners for Surfaces & Irrigation Sources (Hydrogen Peroxide & Sanitizers)

Plant interacting interfaces, i.e. surfaces, benches, walls, floors, trays, utensils, clippers, etc. should be sterilized with every use. Methods can include direct wipe-down or scrub, concentrated or diluted sprays or room vaporizers. A good example of hydrogen peroxide (H2O2) liquid would be a food grade sanitizer with 3-35% H2O2 content. Use acceptable diluted versions of these cleaners as appropriate.

Figure 3: Cleaning & Scrubbing, Where’s the PPE?

A commercial example would be Zerotol 2.0 with 27% H2O2 & their proprietary acid mix. Alternatively, you can use direct hydrogen peroxide generators from commercial sources to generate your H2O2 at various concentrations. More detailed examples are included in the complete Integrated Pest Management Guide (link at the end of this article). Establish your procedures for sterilizing your rooms and tools before you introduce plants, and describe what is to be done after every harvest and room turn. Track the cleaning materials used for your operational records. You will find this useful to track operational cost over time.

Sanitizing Acids for Surfaces & Irrigation Sources

Similar to hydrogen peroxide, hypochlorous acid (HOCl) comes in many commercial forms and can also be generated onsite using purchased generators. Commercial mix examples are UC Roots, Watermax and Athena Cleanse. They come in 0.028% to 15% concentrations. Self-generators range in output from highly precise 0.01% to 1% concentrations with more examples in the guide.

Treatment Tools

OK, so enough on cleaning preparation. Here are some tools that can be used to fight back against a pest intrusion:

Non-Chemical Microbial Biofungicide for Pathogens in Soil or Fertigation Water

Microbial fungicides are available to clear nutrient irrigation systems by minimizing pathogens and improving plant resistance to infections. Some fungicide versions target root pathogens by attacking the diseases directly. Others control or suppress common water carried challenges like pythium, rhizoctonia, phytophthora, fusarium and others. Brand names include Botanicare, Bonide, BioWorks, Actinovate, Mycostop and many more. Details covered in the guide.

Non-Chemical Microbial Bioinsecticides for Larval Stages

These biological tools attack the organisms or insects at a physical or mechanical way by breaking down the pest’s nervous system, biochemistry, or structural integrity (exoskeletons, etc.). These are engineered or living organisms (bugs to attack bugs) that are developed as targeted attacks for specific pests. Brand names are BioCeres, Botanigard, Venerate, Bio Solutions and others.

Minimal Risk Chemical Pesticides for Airborne Critters

Figure 3: Example Fungus Gnat Infestation – Royal Queen Seeds blog

Regularly approved for used in most locales, essential oils, natural acids (like citric acid) and insecticidal soap are commonly available in every hydroponic store. These work very well as safe spray “knock-down” insecticides for crawling or flying pests. Commercial examples use a proprietary mix of various oils, citric acids or isopropyl alcohol to do their task (examples in guide). Insecticidal soaps and fungicides for surface cleaning perform a similar purpose and typically use potassium salts or fatty acid mixtures.

Biochemical Pesticides

These tools are used to inhibit insect or fungal growth to acceptable levels. The multifaceted and commonly used neem oil comes in many commercial versions and is a naturally occurring pesticide extracted from the leaves and seeds of the neem tree. Example brand names are Bonide, Monterey, Triact and others. They range in concentrations from 0.9% to 70% concentrations. These oils suffocate living organisms or eliminate moisture to kill insects, spores or fungus at their initiation and throughout their lifespan.

Another option here are Azadirachtins. These act as insect growth regulators and disrupt the bugs natural evolution. Brand names are AzaGuard, AzaMax and others in the guide.

In summary, this week

We summarized some of the many pest control options available for water treatment, soil borne, intermediate or flying pests. We also covered various concentrations for these pesticide and sterilizer options. If you are not familiar with dilution ratios, %, PPM terms and how to apply the correct level of pesticide, you may find our plant science test kitchen blog on this topic of use here.

Chemical access and use should be restricted to employees familiar with their authorized application. PPE is very important to protect any employee that will come in contact with materials, liquids or vapors for chemical resources (gloves, boots, respirators, Tyvek (or equivalent protective wear) suits and eye protection or goggles.

For more detail on each of these treatments, you can see examples for your integrated pest management procedures in our complete white paper for Integrated Pest Management Recommendations, download the document here.

In our next chapter, Pest Population Control Actions, we will review control thresholds and example plans for a range of problems from biofilm build up to white flies and more. Our final chapter after that will suggest an emergency response framework and how to address pest outbreaks. See you next week.

Building An Integrated Pest Management Plan – Part 3

By Phil Gibson
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This is the third in a series of articles designed to introduce an integrated pest management framework for cannabis cultivation facilities. To see Part One, click here. For Part Two, click here. Part Four comes out next week and covers direct control options for pest reduction. More to come!

This is Part 3: Preventive Measures

Preventive measures are a great investment in the profitability of your operations. Our objective is to ensure successful repeat harvests forever. Build your procedures with this in mind. This means maintenance and regular review. We all realize that this work can be monotonous drudgery (we know!), but these procedures will ensure your success.

Figure 1: New Air Shower Access Installation

As a summary to begin, pest access must be limited wherever possible. Employees are the first place to start, but we must also return to our site map and review our facility design and workflows. Every operation has to move plants from nursery through harvest and post-harvest. Where should cleaning happen? Of course, you have to clean up post-harvest but when should this occur during the grow cycle? What is the best way to monitor and clean environmental management systems (i.e. air, water) and what are the weaknesses in the physical barriers between operations? Let’s walk through these issues one-by-one.

Employee Access and Sterile Equipment

Follow procedures to screen and protect your employees both to eliminate pests and to avoid exposing your employees to harmful chemicals or storage areas. Look for ways to isolate your workflow from pest access. Be certain that your facility is airtight and sealed with filtration of molds, spores and live organisms in your air intake areas. Air showers at your access points are important to screen your employees on their way into your gowning areas and grow facility. Clothing should be standardized and shoe coverings or crocs should be provided for all employees that access your interior. Look for ways to stop all pests (embedded, crawling, hopping or flying) in all of your room assignments (mothers, clone, veg, flower, trim and drying). This can be improved with shoe baths, sticky mats, frequent hygiene (hand washing and cleaning stations) and procedures for entry.

Always consider requiring hair & beard nets, shoe covers and disposable gloves in plant sensitive areas.

Chemical Access & Protective Equipment

Figure 2: Example Facility Map – Understand Workflow & Barriers to Pest Access

Personal protection equipment (PPE) is very important to protect any employee that will come in contact with materials, liquids or vapors for chemical resources. Establish procedures for chemical use and train employees in the safe handling of these materials. Typical equipment includes high density chemical protective gloves, boots, respirators, Tyvek (or equivalent protective wear) suits and eye protection or goggles.

Chemical access areas and their use should be restricted to employees familiar with their authorized application. Always remember that cannabis is an accumulator plant, and it will absorb and hold onto chemical treatments. Appropriate isolation and safety procedures must be followed for chemical use. Not following these restrictions can expose your employees to dangerous chemicals or get your entire harvests rejected at testing.

Facility Map & Workflow

Because insects would like to be everywhere and they come in many types (root zone, crawling, flying, microscopic, bacterial or biofilm), the facility workflow must understand where they are and how they might migrate if they penetrate your defenses. Note airflows in your rooms and fan locations so migrations can be predicted once an infestation is located. Where are your opportunities for full clean-up and disaster recovery in your building? Where should you stage maintenance filters, test kits, water and cleaning materials. How best to clean up and dispose of sealed garbage containers or cleaning materials?

Operational Cleaning & Post-Harvest Reset

When compiling your preventative measure documents, it is critical to create a repeatable operating procedure for cleaning and sanitizing your rooms, systems, and growing spaces after each harvest. Plant material handling, cleaning surfaces and wipe methods should all be documented in your Standard Operating Procedures (SOPs). Define what “clean” is. Removing plants and plant debris is pretty clear but define how to drain reservoirs, clean pipes, change filters and clean and sterilize your rooms. Operators must be trained in these SOPs and reminded of their content on a regular schedule. This is how you avoid outbreaks that can crush your profits.

Physical Barriers & Maintenance

Figure 3: HVAC Air Filtration, Dehumidification, & Air Movement, Onyx Agronomics

Document your sealed spaces and define your normal room and access door barrier interfaces. Review the status of any known cracks or gaps in your perimeter. Are there any known leaks or piping that has been seen as a risk or a problem in the past? Are there any discoloring or resident mold locations (Never happens, right?). Baseline how much time and people resource a harvest operation and cleaning effort should take. Will you do this after every harvest or compromise your risk by delaying to every third or fourth harvest? Create your barrier SOP.

Environmental Control & HVAC

Managing the air quality provided to your plants is critical to your yields. Controlling CO2, air movement rates (the leaf happy dance), humidity, air filtration and sterilization methods must be maintained and cleaned on a regular basis. Do you need to change the HEPA or other particulate filters? Is there any UV light sterilization maintenance? We have all seen the home HVAC air conduit cleaning commercials. Your commercial facility is no different. How will you clean your air and water plumbing systems? How often will you perform this full reset? When will you calibrate and data log your sensors for temperature, humidity, CO2 and water resources? Put everything about your environmental set points into your maintenance document and decide when to validate these. Molds, mildews and biofilm hazards are all waiting for unmonitored systems to open the door for access.

In Conclusion, This Week

If you’re an IPM nerd and this dynamic topic did not put you to sleep, you can read more detail and examples for your integrated pest management procedures in ourcomplete white paper for Integrated Pest Management Recommendations, download the document here.

In our next chapter, Direct Control Options, we will review what you can use to protect or recover control of your facility including both chemical and non-chemical tools and methods. In our final two chapters, we will discuss extermination of the determined pests that breach your defenses. And with great expectations, our final chapter will discuss emergency response and time to go to war!

Part Four comes out next week. See you again soon!

Building An Integrated Pest Management Plan – Part 2

By Phil Gibson
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This is the second part of a series of articles designed to introduce an integrated pest management framework for cannabis cultivation facilities. To see Part One, click here. Part Three comes out next week and covers prioritization and preventative measures. Stay tuned for more!

This is Part 2: Pest Monitoring, Record Keeping, & Communications

Begin your pest identification process with a pest scouting document. You have already mapped out your facility with locations and potential access locations. For each of these pest types and room type assignments (mothers, clone, veg, flower), identify your employee scouts, their scouting methods, scouting frequency and the type of likely pest they are to search for and count.

Insect Types and Tracking Methods

Figure 1: Example Sticky Trap Scouting Map

Insect pest types include, but are not limited to, airborne flying or crawling insects, their various egg, lymph, larvae, pupal shells or immature forms. Look for trace remnants, plant damage or feces that let you know they are present in some form. If they are at the mature jumping or flying stage, this can be harder to count, but sticky traps distributed on an even basis around your rooms can make the counting process more consistent from survey to survey.

Note airflows in your rooms and fan locations so migrations can be predicted once an infestation is located.

Insects Can Be Everywhere – Crawlers & Fliers

Insects would like to be everywhere so they come in many types from the obvious flying and crawling types to root-zone microscopic, aquatic, fungal, bacterial or biofilm based. For those of you using soil or media, root-zone insects can be beneficial by digesting and breaking down organic matter into something useful for your plant’s roots (earthworms) or harmful by feeding directly on your plant roots and sucking the life out of your plants from out-of-sight below (nematodes, maggots).

Common pests in a cannabis environment include:

  • White flies – Oval shaped eggs on the underside of leaves, nymphs- oval crawlers that suck on the undersides of leaves, larger stage nymphs with pupae shells as they form wings and mature white flies.
  • Fungus gnats – Clear eggs deposited in overly wet soil or dead plant matter. Clear or white colored larvae in the soil or media, these worm-like critters go through multiple stages of molting as they grow, eventually pupating into brown cocoons and finally small black or dark flies with clear wings that flutter around your plants and suck on your leaves.
  • The dreaded spider mite – Clear, hard to see eggs on the underside of your leaves. These six-legged tiny moving bubbles begin the feeding as larva, add 2 legs in the intermediate and mature nymph stages and finally the oval shaped spider mites that every grower despises, adding their webs around the tops of your plants as their nurseries suck the life out of your flowers.

Insect Transfers of Bacterial Infections

Figure 2: The Dreaded Spider Mite

Many crawlers or fliers you may discover in your grow operation do not generate fungus or bacteria on their own. However, they do routinely pick these up along the feeding way and bring them into your shop. Sap-feeding insects like leafhoppers and aphids use their needle mouths to pierce your leaves to suck on the sap that is nourishing your greenery. These insects consume the fluids and transfer bacteria as they feed. Whiteflies fit into this category of leaf sucking bacteria carrying pests. These pests can make your healthy grow rooms look blotchy with color drained out of your canopy.

Obvious symptoms of these flying/hopping pests are sticky leaves, black fungus mold, or yellowing leaves that show up at the bottom of your plants and work their way upward as the infestation progresses. Leaf curling or plant wilting will be visible in the more advanced stages of these pests.

As if crawlers were not bad enough, invisible fungus and bacteria that get into your water supplies can be the worst challenges of any grow.

Water Sourced Bacteria

Baseline testing of your feed water is critical for any facility. This is true whether you are using surface water, well water or municipal water. Please see the water tutorials on the AEssenseGrows website for details on how to test your water sources and what to look for in the mineral content.

Regardless of your water source, bacteria can be present directly in your water supply, or it can be introduced from infected plant materials from one of your suppliers. Pythium, fusarium and the latest plague, hop latent viroid, are some of the most common threats that attack your plants from your water or soil sources. These can come from your wells, feed lines or plant materials.

Reverse osmosis (RO) is a typical method to clear water of most pathogens and bacteria using water that is pressed through filters with very small membrane apertures. These small openings usually stop impurities, salts and microorganisms. Of course, these systems come in many different types and they have to be maintained to keep their performance quality. Don’t take shortcuts on your RO system.

Once your water source is clean, strict hygiene procedures for tools, equipment and plumbing are the best way to minimize these threats to your plants downstream from your water source. These cleaning efforts are not a guarantee. Pests can still get into even the best facilities. Symptoms of these maladies vary, but root rot, stunted growth, wilting, discolored roots or leaves, and in some cases, the quick death of your plants is possible depending on the critter.

Use your scouting regimen and your data mapping to locate infestations before they expand and damage your facility. Isolate outbreaks and take appropriate measures to address the pests. We will give you suggestions on prioritization and preventative measures to take in the next chapter.

Figure 3: Example Pythium Brown Roots

Pythium is one of the most commonly harbored soil or water carried pests. When it is present and gets into your plants through cuts, natural openings, root surfaces or leaves on weakened plants, it can be devastating. In hydroponic systems, dirty looking brown roots evolve into full root rot if not addressed. Pythium is often the cause. In soil operations, pythium often shows up as wilting or yellowing patches on leaves.

Your lab testing partners are your friends when it comes to bacterial or fungal infections. Many diseases can resemble one another. It is not hard to misdiagnose environmental stress such as overheating or overwatering for a bacterial problem. Test results are necessary to accurately diagnose a problem.

Truly Airborne Molds & Mildews

Pythium and fusarium are not just present in water. They can also be airborne. Grey mold (botrytis) and powdery mildew are also common airborne pests. Proper humidity, air movement, air filtration and sterilization using HEPA (High-Efficiency Particulate Air) filters, activated carbon filters (also filter smells) and UV light sterilization can minimize these problems in your grow. Powdery mildew is the primary evil spore in this category. Airflow and regular cleaning to discourage fungal growth is the best way to limit these pests.

In conclusion, this week

Now that we have talked about identification (and clearly, this is not an exhaustive list), we will move into how to build in the cultural methods to prevent these problems from taking hold and ruining your business. In later chapters, we will dive into prioritization, treatment and control options for infestations, finally moving into control actions and emergency response.

Your integrated management response is how you pull all of this together and use your IPM procedures to increase your profitability. For the complete white paper on Integrated Pest Management Recommendations, download the document here.

Part three comes out next week and will delve into the world of Preventative Measures. Stay tuned for more!

Building An Integrated Pest Management Plan – Part 1

By Phil Gibson
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This is the first part of a series of articles designed to introduce an integrated pest management framework for cannabis cultivation facilities. Part one details an overview of the plan as well as pest identification. Part two comes out next week and will delve into the world of pest monitoring and record keeping. Stay tuned for more!

Figure 1: Integrated Pest Management Cycle

Background

Integrated Pest Management (IPM) is a philosophy of pest prevention and control that integrates cultural, mechanical, physical and chemical practices to control pest populations within an acceptable degree of economic tolerance.

IPM encourages growers to take a step-wise approach to determine the most appropriate means necessary for avoiding pest-related economic injury through careful consideration of all available pest control practices.

When practicing IPM, less invasive non-chemical practices are given priority, until escalation necessitates otherwise.

This is Part 1: Pest Identification & Monitoring/Communications

Personal experience in a facility is a great place to start. Review your history and identify a list of pests that you have experienced in this or previous grows. Point out which pests currently exist where they were or are currently and possible sources of the contamination/infestation.

Figure 2: Healthy Aeroponic Mother Stock

Map out your facility with clear entry/exits, plumbing & drainage and air flow access to visually see and understand potential access points for crawling, flying or airborne pests.

From your nursery mother room to cloning and vegetation areas, what are the transfer methods as you move from one area to another. Are pests present in these areas? Where could they have come from? Oftentimes, a cultivator may not have the space for their own mother and cuttings/cloning space. In these cases, where did the outsourced clones come from? What are the IPM controls in place for these genetic sources? Are they carriers of the challenges transferred to your own facility? It is important to identify the possible source of pest potentials

Does your flower room have white flies or fungus gnats? Locating these and identifying the likely source is a good place to start if you have an ongoing infestation.

Figure 3: Example Aeroponic Facility Layout For IPM Planning

Powdery mildew is a routine challenge if air into your facility is not filtered and sterilized to eliminate these spores.

What is the Source of Your Irrigation/Fertigation Water?

Water is a crucial element for high-value indoor farms such as those that grow cannabis. However, water can also be a source of disease-causing microorganisms that can negatively impact the growth and yield of crops. Monitoring, filtering and sterilizing the biological contents of water is therefore crucial in ensuring the health and quality of high-value crops.

Unfiltered water can contain a range of pathogens such as bacteria, viruses, fungi and parasites that can cause root, stem and bud rot. These diseases can cause significant losses in crop yield and quality, which can be devastating for indoor farmers growing high-value crops.

Figure 4: Precision Aeroponics at FarmaGrowers GMP Facility, South Africa

Monitoring the quality of water that is brought into the indoor farm is the first step in ensuring that the water is free from harmful pathogens. This involves regular testing of the incoming water for parameters such as pH, dissolved oxygen, TDS, nutrient content and microbial load. This allows cultivators to identify aspects of the incoming water they need to address before the water is provided to their crops to prevent potential problems.

Is your plumbing building biofilm that is feeding into your irrigation lines? Obviously, there are many potential sources when you go through an inventory of the risks for your facility. From that initial step, you will build your management team and label who should be contacted when a pest is found. Do you have an IPM specialist or is this a resource that needs to be contracted to address an infection?

Building this communications tree is your first step to fewer pest issues and higher yields and potency.

For the complete white paper on Integrated Pest Management Recommendations, download the document here. Part two comes out next week and will delve into the world of pest monitoring and record keeping. Stay tuned for more!

A greenhouse grow facility

The Science of Cultivating Cannabis: Tips for a Thriving Grow Operation

By Nathan Johnson, Ph.D.
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A greenhouse grow facility

Creating a healthy cannabis growing environment based on the science behind growing top-notch, medical-grade cannabis is essential for producing consistent results, assuming you start with quality genetics. Before speaking about the environment, it is necessary to highlight that quality and consistency has to first start with quality plant material. In this article, we will explore six key factors that make for a healthy cannabis growing environment and how regular testing allows growers to achieve consistency and quality. Keep in mind, optimizing these factors to the cannabis strains and environment they are grown in is a must.

Lighting

Lighting is the most important factor in creating a good cannabis growing environment. Cannabis plants require specific types, wavelength and exposure times to grow and produce high-quality flower. The two main types of light that are essential for cannabis growth are blue and red spectrum light where blue is primarily dedicated to vegetative growing and red for flowering. The exposure time is necessary for non-autoflower cannabis to maintain a vegetative or a flowering plant.

lightwavesincTo ensure that the plants are receiving the right type and amount of light, growers can use specialized grow lights that provide both blue and red spectrum light. They can also monitor the intensity and duration of light using light meters and timers. Regular testing of the light spectrum and intensity can help growers fine-tune their lighting setup for optimal plant growth and flower development.

Temperature

Temperature always needs to be considered when creating a strong, healthy cannabis growing environment. Cannabis plants prefer a warm, humid environment, but temperatures that are too high or too low can negatively affect plant growth and flower development. The ideal temperature range for cannabis growth is between 70-85°F (21-29°C) during the day and between 58-70°F (14-21°C) at night.

To maintain a consistent temperature in the growing environment, growers can use temperature-controlled grow rooms or HVAC systems. They can also monitor the temperature using digital thermometers and adjust the temperature as needed. Regular testing of the temperature can help growers identify and address any temperature fluctuations that may affect plant growth and flower development.

Humidity

Like other factors that require precision, humidity needs to be carefully dialed in when creating an optimal cannabis growing environment. Cannabis plants prefer a humid environment, but too much humidity can promote the growth of mold and mildew. On the other hand, low humidity can cause the plants to dry out and become stressed.

A humidity sensor mounted in a weatherproof enclosure
A humidity sensor mounted in a weatherproof enclosure

To maintain a consistent humidity level, growers can use humidifiers and dehumidifiers in the growing environment. They can also monitor the humidity level using a hygrometer and adjust the humidity as needed. Regular testing of the humidity level can help growers identify and address any issues that may affect plant growth and flower development.

Airflow and Ventilation

Proper ventilation helps regulate temperature and humidity and prevents the buildup of carbon dioxide, which can be harmful to the plants. It also helps prevent the growth of mold and mildew. To ensure proper airflow and ventilation, growers can use fans and air ducts in the growing environment. They can also use carbon filters to remove odors and other contaminants from the air. Regular testing of the air quality can help growers identify and address any issues that may affect plant growth and flower development.

Nutrients

Nutrients are a non-negotiable for cannabis growth and flower development. Cannabis plants require a balanced supply of macronutrients such as nitrogen, phosphorus and potassium, as well as micronutrients such as calcium, magnesium and iron.

To ensure that the plants receive the right amount of nutrients, growers can use nutrient-rich soils or hydroponic systems. They can also supplement with fertilizers and other nutrients. Regular testing of the nutrient levels in the soil or growing medium can help growers adjust their nutrient regimen for optimal plant growth and flower development.

Pest and Disease Management

Cannabis plants are susceptible to over 90+ pests and diseases, including insects, mold, mildew, viruses and viroids commonly infected through the environment by touch, air, water and nutrients. The most common are spider mites, aphids, powdery mildew, botrytis, fusarium and hop latent viroid. It is estimated by the United Nations that 20% to 40% of total global crop loss is due to improper pest and disease management. The cannabis growing environment is no different.

Damage from whiteflies, thrips and powdery mildew could be prevented with an appropriate IPM

While lighting, humidity, air flow and nutrients are key aspects for a cannabis growth environment, the most common overlooked aspect of growing is proper pest and disease management. Cannabis plants are susceptible to a variety of pests and diseases, which can have a significant impact on plant health and crop yields. To take optimizing a cannabis growing environment one step further, here are five essentials for developing an effective pest and disease management setup.

  1. Prevention

Prevention is the first and most important step in pest and disease management. Growers should always take steps to prevent pests and diseases from entering or infesting the growing environment in the first place. This can be done by quarantining new plants or clones, using clean equipment, sterilizing the growing area, and monitoring plants for signs of pests and diseases through both visual inspection as well as testing.

Some diseases such as those caused by viruses and viroids, require molecular based testing to identify. Growers should quarantine and test any new plants or clones before introducing them to the growing area. This can help prevent the spread of pests and diseases from infected plants to healthy ones. Growers can also use biological controls, such as beneficial insects, to help prevent pests from infesting the plants. These insects can help control pest populations by preying on them or interfering with their reproduction.

  1. Early Detection

Early detection is key to preventing an entire crop from being infected and scrapped. Growers need to regularly inspect their plants for signs of pests and diseases, including yellowing leaves, discoloration, spots and unusual growth patterns. Early detection can help prevent the spread of pests and diseases and limit the damage they cause, not to mention saving a business’s bottom line!

  1. Integrated Pest Management

Integrated Pest Management (IPM) is an approach to pest and disease management that involves a combination of preventative measures, biological controls and chemical treatments. IPM aims to reduce the use of chemical pesticides, which can be harmful to the environment and human health.

IPM involves regular monitoring of plants for signs of pests and diseases, using biological controls to prevent and control infestations, and only using chemical treatments as a last resort. Chemical treatments should be used sparingly and only when necessary, and growers should follow all safety precautions when using them.

  1. Sanitation

Taking the necessary precautions to ensure all equipment used throughout a cultivation is properly sterilized will save growers from countless headaches. Growers should keep the growing area clean and free of debris, which can provide a breeding ground for pests and diseases. They should also regularly sterilize equipment and growing containers to prevent the spread of pathogens.

  1. Record Keeping

Record keeping is essential for effective pest and disease management in the growing environment. Keep detailed records of all pest and disease issues, including the type of pest or disease, the severity of the infestation, and the treatments used. Cultivators, you will thank yourselves later! This will help identify recurring issues and develop effective pest and disease management strategies.

While there are key aspects of creating a healthy cannabis growing environment, the most common overlooked aspect of growing is on proper pest and disease management, which involves prevention, early detection, integrated pest management, sanitation, quarantine, and record keeping. By taking these steps, growers can help ensure the health and vitality of their plants, produce high-quality cannabis that consumers want and preserve their business’s bottom lines.

The 3-Legged Stool of Successful Grow Operations: Climate, Cultivation & Genetics – Part 4

By Phil Gibson
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This is Part 4 in The 3-Legged Stool of Successful Grow Operations series. Click here to see Part 1, here to see Part 2, and here to see Part 3. Stay tuned for Part 5, coming next week.

Integrated Pest Management (IPM)

Aeroponic & hydroponic systems can operate with little to no soil or media. This eliminates the pest vectors that coco-coir, peat moss/perlite and organic media can harbor as part of their healthy biome approach. Liquid nutrient systems come at the nutrient approach from a different direction. Pure nutrient salts (nitrogen, potassium, magnesium and trace metals) are provided to the plant roots in a liquid carrier form. This sounds ideal for integrated pest management programs, but cultivators have to be aware of water and airborne pathogens that can disrupt operations. I will summarize some aspects to consider in today’s summary.

The elimination of soil media intrinsically helps a pest management program as it reduces the labor required to maintain a grow and the number of times the grow room doors are opened. Join that with effective automation with sensors and software, and you have immediate improvements in pest access. Sounds perfect, but we still have staff to maintain a facility and people become the number one source of contamination in a grow operation.

Figure 1: Example of Pythium Infected & Healthy Roots

Insects do damage directly to plants as they grow and procreate in a grow room. They also carry other pathogens that infect your plants. For example, root aphids, a very common problem, are a known carrier of the root pathogen, Pythium.

Procedures

One of the most common ways for pests to access your sealed, sterile, perfectly managed facilities are in the root stock of outsourced clones. If you must start your grow cycles with externally sourced clones, it is strongly recommended that you quarantine those clones to make sure that they do not import pest production facilities into your operation. Your operation management procedures must be complete. If you take cuttings from an internal nursery of mother plants, any pathogens present in your mother room will migrate through cuttings into your clones, supply lines, and subsequently, flower rooms.

Figure 2: Healthy Mothers & Clones, Onyx Agronomics

Start your gating process with questioning your employees and visitors. Do they grow at home or have they been to another grow operation in the last week? In the last day? You may be surprised by how many people that gain access to your grow will answer these questions in the affirmative.

Developing standard operating procedures (SOPs) that are followed by every employee and every visitor will significantly reduce your pest access and infection rates, and hence, increase your healthy harvests and increase your profitability. Procedures should include clothing, quarantining new genetics and cleaning procedures, such as baking or irradiating rooms to guarantee you begin with a sterile facility. This is covered more in the complete white paper.

Engineering Controls

Figure 3: Access Control: Air Shower, FarmaGrowers

Technology is a wonderful thing but no replacement for regimented procedures. Considered a best practice, professional air showers, that bar access to internal facilities, provide an aggressive barrier for physical pests. These high velocity fan systems and exhaust methods blow off insects, pollen and debris before they proceed into your facility. From that access port into your grow space, positive air flow pressure should increase from the grow rooms, to the hallways, to the outside of your grow spaces. This positive airflow will always be pushing insects and airborne material out of your grow space and away from your plants.

Maintaining Oxidation Reduction Potential (ORP)

ORP is a relative measurement of water health. Perfect water is clear of all material, both inert and with life. Reverse osmosis (RO) is a standard way to clear water but it is not sufficient in removing microscopic biological organisms. UV and chemical methods are needed in addition to RO to clear water completely.

ORP is an electronic measurement in millivolts (mV) that represents the ability of a chemical substance to oxidize another substance. ORP meters are a developing area and when using a meter, it is important to track the change in ORP values rather than the absolute number. This is due to various methods that the different meters use to calculate the ORP values. More on this in the white paper.

Oxidizers

Figure 4: AEssenseGrows Aeroponic Nozzles

There are two significant ways to adjust the ORP of a fertilizer/irrigation (fertigation) solution. The first is by adding oxidizers. Examples are chemical oxidizers like hydrogen peroxide (H2O2), hypochlorous acid (HOCl), ozone (O3) and chlorine dioxide (ClO2). Adding these to a fertigation solution increases the ORP of the fertigation solution by oxidizing materials and organic matter. The key is to kill off the bad things and not affect the growth of plants. Again here, the absolute ORP metric is not the deciding factor in the health of a solution and the methods by which each chemical reaction occurs for each of these chemicals are different. This is compounded by the fact that different ORP meters will show different readings for the same solution.

Another wonderful thing about automation and aeroponic and hydroponic dosing systems is that they can automatically maintain oxidizing rates and our white papers explain the methods executed by today’s automation systems.

Water Chilling

Another way to adjust ORP is to reduce the water temperature of the reservoirs. Maintaining water temperature below the overall temperature of your grow rooms is imperative for minimal biological deposition and nutrient system health. Water chillers use a heat exchanger process to export heat from liquid nutrient dosing reservoirs and maintain desired temperatures.

The benefit of managing ORP in aeroponic and hydroponic grow systems is highly accelerated growth. This is enhanced in aeroponics due to the effectively infinite oxygen exchanging gases at the surface of the plant roots. Nutrient droplets are sprayed or vaporized in parallel and provided to these root surfaces. Maximizing the timing and the best mineral nutrients to the root combustion is the art of grow recipe development. Great recipes drive superior yields and when combined with superior genetics and solid environmental controls, these plants will deliver spectacular profits to a grow operation.

Another Hero Award

Before closing this chapter, we have many cultivators that are producing stellar results with their operational and IPM procedures, so it is hard to choose just one leader. That said, our hats are off to RAIR Systems again and their director of cultivation, Ashley Hubbard. She and her team are determined to be successful and drive pests out of their operations with positive “little critters” and the best water treatment and management that we have seen. You are welcome to view the 7-episode walkthrough of the RAIR facility and their procedures here.

To download the complete guide and get to the beef quickly, please request the complete white paper Top Quality Cultivation Facilities here.

Stay tuned for Part 5 coming next week where we’ll discuss Genetics.

Mark Your Calendars: The Cannabis Cultivation Virtual Conference Returns

By Cannabis Industry Journal Staff
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On March 23, 2021, Cannabis Industry Journal is hosting our annual Cannabis Cultivation Virtual Conference. From Noon to 5 pm EST, you’ll get access to nine veterans of the cultivation market discussing a variety of topics related to the ins and outs of growing cannabis and hemp.

Hear from subject matter experts who will share their perspectives on growing organically, facility design and planning, hemp farming and integrated pest management.

Back in December during the Cannabis Quality Virtual Conference, the Cultivation Technology episode featured a session titled A Panel Discussion: Integrated Lifecycle of Designing a Cultivation Operation. Due to a large amount of interest and attendee questions that the panel did not have time to address, we are reprising this panel discussion and bringing it back on March 23.

Speakers for that panel discussion include: Gretchen Schimelpfenig, PE, Technical Director of Resource Innovation; Brandy Keen, Co-Founder & Sr. Technical Advisor at Surna, Inc; Adam Chalasinski, Applications Engineer at Rough Brothers/Nexus Greenhouse Systems/Tetra; David Vaillencourt, Founder & CEO of The GMP Collective, and Kyle Lisabeth, Vice President of Horticulture at Silver Bullet Water.

Other talks from the Cannabis Cultivation Virtual Conference on March 23 include:

  • Why CBD Companies Should Go Organic
    • Brad Kelley, COO of Socati
  • The Beginner’s Guide to Integrated Pest Management
    • David Perkins, Founder of Floresco Consulting
  • Starting from Scratch: Launching a Hemp Farm in Georgia
    • Reginald “Reggie” Reese, Founder & CEO of The Green Toad Hemp Farm
    • Dwayne Hirsch, President & Chief of Business Development at The Green Toad Hemp Farm

You can check out the agenda in its entirety and register here. Attendees will have the opportunity to ask speakers questions during the live Q&A session that follows each session. Registration is complimentary. For sponsorship opportunities, contact RJ Palermo at Rj@innovativepublishing.net

The Beginner’s Guide to Integrated Pest Management

By David Perkins
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Formulating a Plan

In this article you will learn how to control pests and improve the health of your cannabis plants using integrated pest management, commonly referred to as IPM. This involves a multi-point strategy – there is no quick fix, nor is there one solution that will wipe out all your pest problems. Proper pest management requires patience, consistency and determination.

It is important to understand that not all pesticides are bad. While many are incredibly harmful not only to pests, but also humans, in this article I will educate you about some of the safer alternatives to traditional pesticides. It is possible to safely control unwanted pests in your cannabis garden without harming yourself, your employees or the natural habitat around you.

Every cultivation facility should have a well-thought-out plan for their pest management program. This program should account for the prevention, and if necessary, eradication of: spider mites, russet mites, fungus gnats, root aphids, thrips and caterpillars. These are just a few of the more common pests you’ll find in a cannabis garden. There could also be many other less commonly known bugs, so you have to be vigilant in looking closely at your plants, and the soil, at all times. Complete eradication of a targeted pest can be difficult. Once a pest has established itself, decimating or decreasing the population will require an aggressive regimen that includes spraying daily to control populations and prevent other pests from getting established.

Spraying or applying pesticides to the foliage of plants isn’t the only way to control or eradicate pest populations. There are many other ways that you can minimize the spread of pests without the use of pesticides. In greenhouse and outdoor grows, growing specific types of plants around the cultivation area will attract both beneficial and predator bugs that will naturally control pest populations. Some plants that attract these bugs are: mint, peppers, and marigold. Beneficial and predator bugs, such as ladybugs, predator wasps and predator mites, can control unwanted pest populations in the area before they even have a chance to become a problem in your garden. Plants and flowers that attract bees, birds and insects will also create helpful bio- diversity, making it more difficult for the unwanted pests to thrive.

For indoor cultivation, it is imperative that you have your cultivation facility set up for a proper workflow. If you already have pests, you need to make sure you are not contaminating the rest of your facility when going from one area to the next. Make sure that you only go to contaminated areas at the very end of your day, and when you’re done working in that area, you must immediately exit the building. Do not ever walk back through the uncontaminated parts of your facility or the pests will spread quickly.

An aphid on a plant in a greenhouse

When most people think of pests in their cannabis garden they think of the more common varieties: spider mites, russet mites, aphids and thrips. However, there are also soil-dwelling pests that can exist, without your knowledge. These will decrease the health and vigor of your plants, without you even knowing they’re there, if you’re not careful to check for them. Some of the soil dwelling pests that plague cannabis plants are: root aphids, fungus gnat larvae and grubs. It is just as important to control the pests below the soil, feeding on your roots, as it is to control the pests that feed above soil on your plants.

Maintaining healthy plants is essential to controlling pest populations, both on the foliage and below the soil. Healthy plants will have an easier time fighting off pests than unhealthy plants. Plants have immune systems just like humans, and the stronger the plant’s immune system, the more likely it will be able to ward off pests and diseases. Allowing a plant to reach its full potential, by minimizing pests, means your plants will also have a better quality, smell and flavor, not to mention a bigger yield.

Worker Safety, Regulation and REI times

The application of pesticides requires certification from the state agricultural department. In certain situations, depending on the type of pesticide and method of application, a license may even be required. The application of pesticides without proper certification is against the law. Applying pesticides in a manner that is not in accordance with the label and instructions is also a violation of law.

The proper personal protective equipment (PPE) is required for anybody handling, mixing or applying pesticides. Employees can be a liability to your company if they are applying pesticides improperly. Make sure you and your entire staff are well educated about pesticide use requirements and limitations, prior to usage, and that only a properly certified person is handling the mixing and application at your facility.

The author, David Perkins, In his greenhouse after using insect killing soap.

After a pesticide is applied, you must abide by the re-entry interval (REI). This is the required time period limiting all workers from re-entry into areas where pesticides have been applied. This time period will vary depending on the type of pesticide used and the method of application. In some instances, pesticides applied in the last 30 days may require employee training before work can be done in those areas.

The misuse of or improper handling of pesticides is not only unlawful and dangerous to human health, but can also cause environmental damage to waterways and wildlife. The direct effects of pesticides on wildlife include acute poisoning, immunotoxicity, endocrine disruption, reproductive failure, altered morphology and growth rates and changes in behavior. Pesticides can indirectly impact wildlife through reduction of food resources and refuses, starvation due to decreased prey availability, hypothermia and secondary poisoning. Section 1602 of the California Fish and Game Code governs requirements for permitting of any project where pesticides will be used, and strictly regulates the disposal of all waste and run-off. It is imperative to know the regulations and to abide by them, or heavy fines will ensue!

Using Pesticides in a Regulated Market

Knowing which pesticides you can’t use, to avoid failing mandatory state testing, is just as important as knowing which ones you can use safely to pass required testing. Most states with regulated markets have strict limitations on the pesticides that can be used in cannabis cultivation. Pesticide use in the cultivation of cannabis is the most strictly regulated in the agriculture industry; the pesticides allowed for use in cannabis cultivation are far more limited than any other crop.

Photo: Michelle Tribe, Flickr

Just because a product is certified organic does not mean that it can be used, or that it is safe to be consumed or ingested. Oftentimes when cannabis flower alone is tested it will not fail or show a detectable amount of pesticides or heavy metals. However, when that flower is turned into concentrates, banned substances are then detected in testing, leading to test failures.

Cannabis cultivation facilities that are located on land that was previously used for conventional agriculture, or located near vineyards or other agricultural crops that are heavily sprayed with harmful pesticides, run a very high-risk failing testing. This is because of either spray drift from nearby agriculture, or residual pesticides and heavy metals left in the soil from previous crops that were using pesticides banned for cannabis cultivation. Accordingly, if you’re going to be growing outdoors or in a greenhouse, it is imperative that you get a soil and water test prior to cultivation, so you can determine if there is any potential for test failures due to pesticides or heavy metals in the soil or water in that area. 

Proper Application – Using the Right Tools in the Right Way at the Right Time

One of the most important factors in pest management is proper identification of pests and proper application and coverage of pesticides. It does not require an entomology degree to identify insects, these days there is a lot of information online that can help you identify cannabis pests. Proper identification of insects can make the difference between success and failure. With a good eye and a microscope, if you do your research, you can control most insects in your garden.

In order to control pests in your garden you must get proper coverage of the foliage of the plant when you are applying pesticides. There are different types of equipment that are commonly used to apply pesticides in cannabis cultivation: backpack sprayers, foggers, and airless paint sprayers are the most common. An alternative method involves using an automated dosing system such as a dosatron, which injects fertilizer or pesticides at a specific ratio into your water lines, allowing you to use only the exact amount of pesticide you need. That way you avoid wasting money on unused pesticides. It is also safer for employees because it minimizes employee exposure, since there is no mixing required, and it allows for a large volume to be sprayed, without refilling a tank or a backpack sprayer.

No matter what you are using you must ensure you get the proper coverage on your plants in order to control pests. The temperature and humidity of your cultivation area, as well as the PH and temperature of the pesticide solution, all factor into the success of your IPM. For example, PFR 97 needs to be applied at a higher humidity range, around 70% to be most effective. In some areas this is not possible so repeated applications may be required to ensure the application is effective. A high PH or alkaline PH can cause alkaline hydrolysis which will make your pesticide solution less effective and will dictate how long your pesticides remain effective after they are mixed. It is therefore important to use your pesticide solution as soon as you make it; don’t let it sit around for long periods of time before use or it will be less effective.

In cannabis cultivation there are two different primary growth cycles: vegetative and flower. These cycles require different IPM strategies. In general, during the flowering cycle, pesticides should not be applied after the second week, with some limited exceptions i.e. for outdoor cultivation there is a longer window to spray since the flower set takes longer than a plant being grown inside, or in a light deprivation greenhouse, where there is a 12/12 flowering cycle.

Starting with an immaculate vegetation room is crucial to maintaining pest and mold free plants in the flowering cycle.

For the vegetative (non-flowering) cycle, a strict rotation of foliage spray applications targeting not only pests, but also molds and pathogens, will be necessary to avoid a quick onset of infestation. Starting with an immaculate vegetation room is crucial to maintaining pest and mold free plants in the flowering cycle. Preventative sprays that are safe for use include: safer soap (contact kill) for soft bodied chewing insects; Regalia (biological control) for powdery mildew; and PFR 97 (biological control) for soft bodied chewing insects. It is also helpful to spray kelp, which strengthens the cell walls of plants, making the plant healthier, and thus enabling the plant to better defend itself from pests and diseases. Also, Bacillus thuringiensis (Bt) is useful to prevent or kill caterpillars.

The best way to control a pest infestation in the flowering cycle is at the very beginning on day one. You must start aggressively, with a three-way control consisting of a contact kill and preventative during days 1-14; preventative and biological control during days 10-18; and then release predator bugs on day 25, for optimal results. Knocking back the population with an effective contact kill pesticide early on is essential to ultimately lowering populations throughout the grow cycle, so that you can spray a biological control to preclude them from returning, before you release the predatory bugs at the end of the cycle.

Biological controls can take anywhere from 3 to 10 days before they are effective. Biological pesticides are selected strains of bacteria or fungus. When the plant tissue is eaten by a targeted pest, the bacteria kills the pest from the inside providing control without having to spray pesticides repeatedly. Predator bugs are the last line of defense, used in late flowering. They can be used indoors, outdoors and in greenhouses. An example of a common predator bug is Amblyseius californicus used to control low populations of spider mites, but there are many different varieties and they are specific depending on the type of pest population you seek to control.

A common concern with the use of predatory bugs, is whether they will be present when the flowers are harvested. However, if there is no food for the bugs (i.e. pests) the predator bugs will leave in search of food elsewhere. Further, indoor predator bugs are usually very small in size and difficult to see to an untrained eye. It is very unlikely to see any signs of predator bugs near the end of the flowering cycle, or in the finished flower product. Even when using bigger predator bugs, the bugs will leave the plants when harvested and dried.

Having pests can be very stressful. It is not uncommon to have bugs, pests, rodents, animals and birds cause damage in cannabis gardens. Making an informed decision based on science and not on unproven assumptions can determine how successful you are at pest management. There are many factors that go into pest management and no one situation is the same. You must be dedicated and consistent; pest management never stops. You will always have something ready to invade your garden. Prepare, plan, prevent and repeat!

Soapbox

Clean Grow Still Failing? Check for Endophytic Mold

By Bernie Lorenz, PhD
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The journal Frontiers in Plant Science recently shared an important article from researchers at Simon Fraser University in British Columbia, highlighting the “Pathogens and Molds Affecting Production and Quality of Cannabis Sativa.”

As a chemist focused on the science of preventing and mitigating mold in greenhouse and indoor cannabis grow facilities, this piece was fascinating to me. Like many others, it details and explains prevalent mold like Penicillium, Cladosporium and Aspergillus – things I see in grows every day.

But wait, there’s more fungi

The research and resulting article also brought up another type of fungi – endophytic mold. Endophytic mold usually lives symbiotically with plants, or is at least beneficial for both plant and fungi.

But not always.

In the past, the industry has believed that damaging mold spores were found on the outside of the flower. When moved, that flower would release the spores and send them flying – often creating massive cross-contamination issues for indoor grows.

Hope Jones, PhD, CEO of Adivina & ECS

“While cannabis is an incredibly powerful plant in terms of its medicinal properties, it is unfortunately highly susceptible to many pest and pathogens,” says Hope Jones, PhD, CEO, Adivina & ECS. “And it is this susceptibility that is so challenging to many inexperienced or undisciplined grow operations.”

Now, however, we know that there’s another culprit to add to the list: the inner parts of the plant can also be a source of endophytic cross contamination and mold.

Since it grows inside of the plant, this fungus creates high spore counts that can cross contaminate from outside, into the flower.

Treating mold in a facility

Here’s the good news:

This seemingly bad news – that there’s a new fungus to worry about, and it is inside the flower – may actually help cannabis grows struggling with mold, and those who are following the proper protocols already.

A petri dish of mold growth from tested cannabis Photo credit: Steep Hill

Effective mitigation protocols can include things like treating HVAC systems, controlling humidity, using products like chlorine dioxide to treat irrigation lines, enforcing protective clothing and shoe covers for employees, reducing the amount of in-and-out for employees around grow rooms.

These are important upstream and environmentally-focused integrated pest management (IPM) programs that will usually keep facilities clean and relatively mold-free.

But if these programs are in place, and there’s still an issue, Endophytic fungi may be to blame.

If you are having ongoing mold issues but have ruled out cross-contamination and a facility without proper protocol, look to the mother plant.

“Small mistakes in agricultural practices are amplified with cannabis,” Dr. Jones continues. “And today’s propagation practices of traditional cloning add to this vulnerability. Cannabis is an annual plant and by keeping mothers in a perpetual state of vegetative growth for years, and taking repetitive cuttings produces clones in a highly stressed state. This stressed state diminishes genetic potential and weakens a plant’s ability to fight disease and pests.”

Testing for and addressing endophytic fungi

If these concerns are ringing a bell, remember, there is also a way to test for Endophytic mold.

Checking cuttings from suspected mother plants over a period of time is the best way to see if the Endophytic mold is present.

A section of the mother plant cutting is placed into a solution (for example, as outlined by the article, a very concentrated hypochlorite followed by 70% Ethanol) that will kill all of the microorganisms that are present on the surface of the plant tissues.

A large tissue culture facility run in the Sacramento area that produces millions of nut and fruit trees clones a year.

From there, an unadulterated dissection of the internal tissues can be extracted and cultured for quantification and identification of endophytic fungi.

“Tissue culture offers a form of genetic rebooting returning the plant to its natural genetic potential and thereby strengthening its natural ability to defend against environment assault,” says Dr. Jones. “It also allows the breeder to conduct pathogenic disease testing which provides the entire industry with a higher level of scientific certainty and analysis.”

If you find this mold inside of the mother plant, your facility’s mold problem could be a systemic issue, not an environmental one.

If you do find that Endophytic mold is causing issues, of course, you may have to destroy the mother plant.

This should not mean the end of a strain. Tissue culture on a cutting is an option that can eliminate the unwanted fungi and save the genetics. Using those genetics to regrow a mother will start fresh and avoid the intrinsic mold that was plaguing the strain prior.

Growing knowledge

The practice of checking mother plants for Endophytic mold is not yet commonplace in cannabis, but the hemp business is leading the way.

They’re testing to create very clean plants, so you don’t have issues during cultivation.

Major growers in the U.S. could save millions in lost harvests with mold mitigation. If your current IPM program isn’t doing the trick, you may want to follow in hemp’s footsteps and look inside the plant.