Tag Archives: osmosis

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!

The 3-Legged Stool of Successful Grow Operations: Climate, Cultivation & Genetics – Part 2

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

Aeroponic and hydroponic systems use zero-soil, so water is effectively our media and our transport mechanism for nutrition. Ideally, you start with clean, fresh water with “nothing” in it. Nothing in this case means no heavy metals, pesticides, bacteria or pathogens. There are some scary words in there so let’s talk through the best ways to get to “nothing.”

The first place to start is by testing your source water, whether it is surface, well or municipal water. This will give you an initial idea of how “empty” your water is. Water supplies shift over time, so it is also a very important input to monitor over time with annual or bi-annual testing. Clean water is the essence of success for aeroponics and a great way to lower your cost of production. With proper design and management, you can recycle and reuse 95%+ of the water you draw into your facility.

Reverse Osmosis (RO)

Mothers to clones: Happy clones, it’s all about the water

RO is the most common way to clear your incoming water. The process uses pressure filtration by forcing your water through a series of filters or meshes that block or extract large particles, organics and metals. Normally this is 98%-99% efficient. These systems do require attention and maintenance as they do have filters that are required to be changed regularly depending on the clarity of your original water source and the type of material filtered. This accomplishes a lot of your water clearing process to empty the balloon, but it does not clear the pesky biologicals or pathogens. RO is covered in detail in our “You are what you drink” webinar so look that over for a deeper explanation. There are a wide range of relatively low-cost suppliers based on capacity and filtration efficiency. From an operations standpoint, the key is to understand the filter replacement cycle and cost of replacement.

Ultraviolet Light (UV)

UV light can be used to clear organics and pathogens from water. The primary use is to clear origin water but it is also especially important for recovered water that you save from the humidity in your grow rooms. More on this below. One has to be cautious about the use of UV light. It will cause sunburn and eye damage with exposure so handle this resource with care. After RO & UV treatment, input water should be an empty balloon ready for the addition of your perfect nutrient salt recipe. There are a wide range of low-cost UV lighting solution suppliers from which to choose and they are easy to find.

Dehumidification & Recovery (DEHU)

Early root follicles: Reaching for first nutrients

The number one way to conserve water in an accelerated growth aeroponic grow room is to recapture the humidity that is transpired into the air as the plants grow. While DEHU water is effectively distilled water (or clear of particulates), it can be full of healthy little bacteria or pathogens than may be transported through air or residing in the equipment filters. Clearing these with UV light normally makes this water directly reusable in your fertigation systems. Not all dehumidifiers are perfect. Some metals used in their construction can leach into the recovered water, so this is worth a deeper look as you create your complete water system. Air treatment suppliers are covered in Part 1 of this series.

Used Fertigation Water, or “Flush”

At the start of the flower cycle, take your clean water (the empty balloon) and add your perfect nutrient salt flower recipe and deliver it to your plants. Over the grow cycle from flower to harvest, your plants will use portions of your nutrients and your balloon contents will drift from your target recipe you’re your desired cycle, clear or flush your reservoirs and reset your recipe by refilling your balloon to your exact targets. The exiting nutrient-rich “flush” water can also be recycled into your source water feed since the salts and metals present can be cleared from the mixture through the same RO process that your source water goes through. The end result is perfectly good recycled water savings.

Oxygen Reduction Potential (ORP)

Healthy roots reach for water: Early veg when plants get rolling

ORP is a measurement of an oxidizing agent. Oxidizing solutions are a common and inexpensive method of disinfecting water before and during use in hydroponic systems. Oxidizers can be used to monitor and deal with the “cleanliness” of a nutrient water solution while it is in use. Several oxidizing agents exist with the most common being: hydrogen peroxide, chlorine, ozone and chlorine dioxide. The characteristics of each of these agents and how they interact with the organic matter in solutions is different. The ideal concentrations to use in each situation to kill or control pathogens is unique and one of the topics covered by our “Letters from the AEssenseGrows plant science team” on our website. That deep dive is the subject of another paper.

When you take all of these subjects together and they are done right, you should be able to recycle 95% of your source water with a professional water treatment & recycling system.

Here, I would like highlight the ultimate water hero: Ashley Hubbard, director of cultivation at RAIR Cannabis. For a quick tour of her water treatment and recovery room, see here. No one that I know manages water better than RAIR Cannabis and Ashley leads the team there.

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 3 coming next week where we’ll discuss The Right Build Out.