The United States Department of Agriculture (USDA) issued its final rule on hemp production, sampling, and testing in January. The requirements on what part of the plant to sample and how to obtain samples from the field are rife with problems. Here, we discuss these problems and propose a better way.

The United States Department of Agriculture (USDA) recently released their final rule entitled “Establishment of a Domestic Hemp Production Program”(1). This was preceded by an Interim Final Rule (IFR) (2), all in support of the 2018 Farm Bill establishing the legality of hemp production in the United States (3). In regards to hemp testing, in conjunction with the final rule the USDA issued a “Laboratory Testing Guidelines U.S. Domestic Hemp Production Program” (4). Additionally, the USDA released a document entitled “Sampling Guidelines for Hemp
Growing Facilities” (5).

In three previous columns I criticized the USDA for their lack of scientific rigor in their proposed rules in a series of articles called “Hemp Testing Insanity” (6–8). Myself and thousands of others took advantage of the public comment period after issuance of the IFR to advise the USDA on best sampling and analysis practices. Unfortunately, now that the final rules are in place it appears the public comments were ignored as few of the suggestions the scientific and hemp farming communities asked for were incorporated. Thus, the sad need for a fourth installment in the “Hemp Testing Insanity” series. Here, I criticize the USDA’s proposed methods of sampling hemp grows and propose solutions.

In the 1930s, infamous bank robber Willie Sutton’s illegal activities landed him on the Federal Bureau of Investigation's (FBI) 10 Most Wanted list. When asked why he robbed banks he simply said, “Because that’s where the money is!” The USDA’s sampling guidelines specify that inflorescence (flower) samples be cut from “…the top one-third {1/3} of the plant.” The USDA defended this approach by saying that flowers from the top 1/3 of the plant only should be sampled because that’s where the tetrahydrocannabinol (THC) is (1). This flies in the face of several well known facts.

The point of testing any marketed product is to analyze what is actually sold. The article of commerce in the hemp industry is typically—whether the crop is to be used for food, fiber, or cannabidiol (CBD) extraction—the whole plant ground up. This means the required sampling plan is not representative of what is being bought and sold by the industry.

We also know in cannabis plants that the cannabinoids concentrate in the flowers, and that the flowers from the top of the plant contain more cannabinoids than flowers from the middle or the bottom. Flowers from the top 1/3 of the plant then contain more cannabinoids than any other part of the plant. This is again not representative of the plant as a whole, and guarantees that the number of failed grows will be maximized by analyzing the part of the plant with the most THC. This is grossly unfair to hemp farmers, and is a threat to the existence of the industry.

One of the purposes of any food or drug testing protocol is to insure that a product’s label accurately describes what a consumer is purchasing. By forcing the industry to test a part of the plant that differs in potency from the part of the plant that is actually sold, the testing is not doing its job because it will mischaracterize what the public is getting. Imagine if we took the same approach with milk testing. If left to stand the cream in raw milk will literally rise to the top. The cream is made up mostly of fat. We will thus have an inhomogeneous sample with more fat at the top than the bottom. The milk we buy at the grocery store is often “homogenized,” which means the fat globules are busted up and mixed in with the rest of the milk to give a product where the fat distribution is homogeneous. And of course the milk carton carries a label stating the percent fat. If we were to follow the USDA’s “because that’s where the THC is” mantra, or in this case “because that’s where the fat is,” we would test the cream at the top for fat and put that number on the homogenized milk carton label rather than the percent fat in the actual homogenized milk—always overstating what is in the carton and resulting in a mislabeled product.

I like to say that hemp is like America—no two people are the same and no two hemp plants are the same. This means that to sample a hemp grow properly a robust representative sampling plan needs to be in place, such as the one I have proposed previously (10). As in the IFR, the USDA’s final regulations use a formula for determining the number of plant samples to take per lot based on acreage, and for small plots to collect one sample per acre. I roundly criticized this approach in a previous column (7). I pointed out that the number of hemp plants per acre, the density, varies widely across the country. A sample taken from an acre with 10,000 plants is not as representative as a sample taken from an acre with 1000 plants in it. To minimize sampling error, the sample size needs to be determined by the population size from which you are drawing the sample, which is in this case the number of hemp plants not the acreage they occupy (7). As I pointed out (7), this approach is like using geographical area rather than population to determine who to talk to when taking an opinion poll. Using the USDA’s methodology we would talk to more people in Alaska than New York City because Alaska is bigger in area than New York City, even though Alaska has 10 times fewer people, to create our poll. Of course the resulting poll would not be representative of the opinion of Americans as a whole. A wise person once said that the definition of insanity is doing the same thing over and over again expecting different results. By reiterating this nonrepresentative sampling rule over and over again, the USDA most certainly is promoting hemp testing insanity. I believe my approach of basing the sample size on density is more scientifically sound (10).

The formula the USDA uses to choose the number of samples to collect from a lot uses a parameter based on “…past experience in the same or similar growing areas” (1). There are a number of problems with this. The first is that farming is not reproducible. Even if you plant the same strain of the same crop in the same field from year to year, variations in the weather, soil conditions, insect infestations, and so forth will cause the chemical composition of the plants from year to year to vary. Second, since hemp has only been legal to grow nationwide for a few years, the needed historical data to use this formula does not exist! There are hundreds of hemp strains, and an incredible variety of environments across the country where hemp is grown. Unless, for example, we have multiple years of the chemical composition of the hemp strain Cherry grown in eastern Oregon, the formula proposed by the USDA is useless.

The Hemp Industry Is Left Holding the Bag

The USDA sampling rules call for collecting a number of hemp samples across a lot, as many as 100 for lots of 150 acres or more. This make sense, the bigger the population the bigger the sample size needs to be. And then they go and ruin it all by putting all those cuttings into one bag and saying that it must be composited. First of all, you are going to need something the size of a garbage bag to collect a hundred hemp samples if you have a big grow. But the biggest problem is that there are no instructions on how to composite such a sample. Imagine what you will see when you look into that big bag of cuttings-buds, stems, leaves, and seeds. That is, a sample that is inherently inhomogeneous. When that bag is delivered to a laboratory they will most likely not composite the whole bag full of cuttings, but will grab a handful, grind it up, and analyze that. This, of course, is not representative. Where are the instructions on how to composite such a large sample? Another practical problem is that laboratories are not used to handling and compositing samples greater than a few grams in size. I doubt most laboratories have a grinder big enough, for example, to uniformly grind samples that weight 100 g or more. And lastly, assuming we did manage to composite that large of a sample, the regulations only require one aliquot of that composite be tested. This is also by definition not representative. We have no idea if this composited sample is uniform or not, and the only way to get around this is to test multiple aliquots and average the results. The USDA gets around this problem by stating that there are no analytical methods available that are accurate, fast, and inexpensive enough to handle this sample load (2). As I have been pointing out throughout numerous columns (6–8, 11), and through my own peer-reviewed work (12,13), infrared spectroscopy is up to this challenge.

The hemp sampling rules issued by the USDA suffer from problems. Requiring that buds from the top 1/3 of the plant be tested means samples will have enriched amounts of cannabinoid in them compared to the plant as a whole. The formula for determining the number of samples to collect in a lot uses the acreage of the lot rather than the number of plants, ignoring the fact that the population size being sampled is determined by the number of plants not how much space they take up. This same formula uses a parameter based on previous growing experience, the problems with which include the irreproducibility of grows from year to year, and the lack of the needed historical data. Lastly, all the samples collected from a lot are composited together. No guidance is given on how to go about homogenizing such an inhomogeneous sample. In addition, only testing one aliquot of the composited sample assumes the sample is homogeneous, which is not necessarily the case.

https://www.federalregister.gov/documents/2019/10/31/2019-23749/establishment-of-a-domestic-hemp-production-program

115th United States Congress, Senate Bill S.2667,” Hemp Farming Act of 2018”.

Hemp Testing Guidelines Issued January 15, 2021 (usda.gov)

Hemp Sampling Guidelines Issued January 15, 2021 (usda.gov)

, is Founder, CEO, and Chief Technical Officer of Big Sur Scientific. He is the inventor of the BSS series of patented mid-infrared based cannabis analyzers. Dr. Smith has done pioneering research and published numerous peer-reviewed papers on the application of mid-infrared spectroscopy to cannabis analysis, and sits on the editorial board of 

. He has worked as a laboratory director for a cannabis extractor, as an analytical chemist for Waters Associates and PerkinElmer, and as an analytical instrument salesperson. He has more than 30 years of experience in chemical analysis and has written three books on the subject. Dr. Smith earned his PhD on physical chemistry from Dartmouth College. Direct correspondence to: 

Articles

Cannabis Analysis 

Why the USDA’s requirements on what part of the plant to sample and how to obtain samples from the field are rife with problems and how to solve them.

Hemp Testing Insanity IV:  Problems with the USDA’s Hemp Sampling Rules

Learn the major choices of substrate and their benefits and disadvantages, the ways watering volume and frequency are affected by substrate choice, the importance of watering rate and leach percentage and how to calculate them, and implications for water quality, recapture, and reuse.

Growing media impacts the effectiveness of watering for plants, a critical process influencing transpiration and uptake of nutrients. Since the dawn of commercially licensed cannabis cultivation, growers have begun to transition from larger substrate volumes and less efficient watering methods to smaller container sizes and greater integration of more precise irrigation techniques. With high-frequency/low volume irrigation approaches, water efficiency and productivity can be optimized. No matter how water is applied, grower methods can be optimized, and opportunities to increase efficiency of water use across the industry are considerable.

Substrate is the base on which plants grow. In commercial food production, soil is the most common substrate. For cannabis, growers often use other media, including rock wool, coconut coir, peat mixed with amendments, or water culture. When selecting a substrate, consider properties such as water retention, recommended irrigation approach, watering rate, leachate percentage, commonly used amendments, and implications for water recapture and reuse to find the right growing media and fertigation methodology.

The most common substrates used for indoor and greenhouse cultivation are described in order of prevalence of use in the legal cannabis market below. A more detailed overview is provided in 

O: Water Use and Sustainability in Cultivation

, Resource Innovation Institute’s (RII) latest collaborative report with New Frontier Data and the Berkeley Cannabis Research Center (1).

Rock wool is fibrous material made from molten rock spun into fibers and formed into plugs, blocks, and slabs of various form factors. The sterile nature of production under extreme temperatures keeps the substrate clean and free of pests and pathogens. It is inert; it does not bind any applied water and nutrition. For this reason, it must be frequently irrigated with nutrient solution. Rock wool can deliver very high plant performance, but can require closer monitoring to ensure balanced production. If rock wool irrigation systems malfunction, plants can more quickly and easily experience drought stress or even permanent wilting damage or death.

 Rock wool has a high water-holding capacity relative to its volume when compared with other substrates, due to its high volume of air.

 There is a learning curve to using rock wool, especially in the cannabis industry where growers are used to irrigating relatively infrequently. It can be irrigated with varying volumes and frequencies of water in relation to the volume of the substrate, and based on the differing needs of the plants during the cropping cycle.

 With uniform fibers and structure, water and nutrient contents can be controlled with minimal leachate. However, because ions are not bound or exchanged on substrate particle surfaces, rock wool can require higher leachate percentage to keep pore water solution elementally balanced and avoid cumulative nutrient imbalances in the plant tissue. Lower leach may be achieved with water culture approaches that recirculate irrigated water.

: Rock wool is always used on its own without any amendments, unless for the exception of instances where a rock wool cube is placed atop a coconut coir slab as is common in tomato, cucumber, or pepper greenhouses.

Coconut coir is compostable and can be sustainably produced. However, during the manufacturing process coir requires significant volumes of water to buffer the substrate (remove unwanted ions that adsorb to the cation exchange sites). If sodium and other chemicals are not washed from the coir they can negatively impact growth performance. The chemical properties of properly composted, washed, and buffered coir provide an optimal pH range for cannabis cultivation, while having low electrical conductivity, sodium, and potassium content.

 Coir can provide excellent water retention, aeration, and drainage under both frequent and less frequent irrigation practices across a variety of container sizes.

 Coir is a very popular growing substrate in the cannabis industry because the physical and chemical properties of coir make it ideal for a range of different irrigation practices, container sizes, environmental conditions, and nutritional strategies.

 Minimal leach percentage ranging from 10–25%.

 Coir is often used on its own, or mixed with perlite, commonly using a 70% coir–30% perlite ratio.

Peat mixes are a very wide-ranging category. Peat-based mixes were historically very common in both unregulated and commercial cannabis production. Coir and rock wool have become more popular as they offer growers greater precision when managing substrate.

 Peat can hold as high a volume of water as coir, but the portion of nonavailable water is greater, because sphagnum moss fibers are softer than coir, and cannot support as much weight.

 Depending on the inclusion and ratios of amendments, peat may need to be watered less often but at higher volumes. Peat mixes are almost always used with a high percentage of perlite in order to increase aeration, but that also decreases water retention.

 No or minimal leachate (10–15% range).

 Peat may be amended with various minerals and organic matter, making the mix much denser (200 to 400 g/L) with higher water retention and lower aeration. Inclusion of expanded mineral (like perlite), wood fiber, or aged bark help to maintain proper aeration.

The impact of substrate on the frequency and volume of irrigation events is affected by the ratio of substrate volume to plant biomass. A grower might use a large volume of peat that only demands low-frequency irrigation but requires larger volumes of water per event to reach uniform saturation. A different grower may use small volumes of a different substrate that necessitate higher-frequency irrigation events at lower volumes due to the overall lower water-holding capacity.

Rock wool: Higher-frequency, lower volume.

 Up to 20 irrigation events a day; frequency and volume depending on the needs of the crop and the volume of the substrate, according to Grodan (the leading producer of rock wool for horticultural use).

Coir: Moderate frequency, moderate volume

. One to 12 water application events a day; frequency and volume depending on the size of the container.

 One to several water applications a day; volume depending on the aeration of the mix affected by ratio of soil amendments.

Deep Water Culture: Constant irrigation, low volume.

 Roots are continually submerged in solution; growers typically top off the solution once or twice a week before a complete solution replacement.

Aeroponics: Higher frequency, lower volume.

 Roots are misted extremely frequently (that is, 5 to 15 or more times hourly) with small pulses of nutrient solution.

Water Quality and Recirculation for Sustainability

Growers considering sustainable cultivation approaches should acknowledge the downstream implications of substrate selection on water quality and employ best practices for water management to monitor watering rates, measure leachate percentage, analyze runoff, and support effective treatment and reuse.

Substrate choice is an important factor influencing the treatment and rebalancing activities of reclamation activities. Naturally derived organic substrates such as peat or coir contain carbon and tend to produce an organic-laden leachate that contains a complex mixture of humic acids, tannins, and other polymeric organic compounds. “From a reuse and treatment perspective, these compounds contribute to an increased load on microbial control processes such as oxidant demand and UV disinfection, as well as carbon and sediment filtration processes,” notes RII member Taylor Robinson, Research & Development Manager and Chief Chemist at Silver Bullet Water Treatment. “Organic compounds from naturally derived substrates can also provide a carbon food source for microbial organisms (beneficial, benign, or pathogenic). While certainly not insurmountable, there may be increased cost and infrastructure requirements to ensure proper water quality when managing organic leachate.”

Organic leachate from rock wool substrates is not usually a concern, but because rock wool is a naturally mined product, it may contain naturally occurring metalloids and introduce chemicals into leachate. Commonly, flushing is employed by manufacturers during quality control to remove soluble metals, but soluble arsenic has been observed by Silver Bullet leaching from unused rock wool substrates. Since cannabis is a bio-accumulator, these compounds have a high potential to be stored in plant tissue throughout the cultivation cycle. Testing “hot” for heavy metals is not a nice surprise for a grower, and in some regulated regions, may deem a crop unfit for consumption or sale.

When using deep water culture (DWC) approaches, “well managed hydroponic systems can be purpose-built to reclaim and reuse water, but also run the risk of microbial or pathogen outbreaks,” noted Robinson. Many DWC and aeroponic installations have large groupings of plants with root zones directly connected via piping and the nutrient stream. If the solution is not tested and actively managed, extensive disease outbreaks may be impossible to correct before substantial crop loss occurs.

Substrate selection is just one of the activities involved in a comprehensive water management plan that addresses fertigation approach, estimation and monitoring of watering rate and leachate percentage, recapture, water quality testing, and rebalancing for recirculation and reuse. Keep an eye out for additional tips for water management in Resource Innovation Institute’s next peer-reviewed 

on Automation & Controls for Cannabis Producers

 coming this summer. As a non-profit organization, RII brings together producers, utilities, designers, builders, and technology providers to help cultivators successfully adopt efficient techniques and ensure resilient harvests into the future.

https://info.newfrontierdata.com/cannabis-h2o

https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/soil-amendments

, is the Technical & Operations Director of RII and facilitates the organization’s Technical Advisory Council, manages the PowerScore resource benchmarking platform, and delivers educational curriculum to the market. She authored the RII Best Practices Guides on 

HVAC and LED Lighting for Cannabis Cultivation and Controlled Environment Agriculture

. Gretchen has a B.S. in Architectural Engineering from the University of Wyoming, an M.S. in Civil Engineering from Stanford University and is a licensed Civil Professional Engineer in California and Vermont. She has experience commissioning HVAC, lighting, and controls systems designs and installations in commercial and industrial buildings, including greenhouses and indoor growing environments used for academic research on a diverse range of cultivars. She also has implemented energy efficiency programs for commercial customers and launched equipment incentive offerings for growers in Vermont.

 is the Director of R&D/Analytics for Silver Bullet Water Treatment and Founder of Rimrock Analytical with expertise in molecular and cell biology, general water chemistry, microbiology, and water treatment and reuse processes. Silver Bullet Water Treatment is a member of RII and active in their Technical Advisory Council’s Water Working Group. For the past 6 years, Taylor has led, conceptualized, organized, and completed numerous Silver Bullet research and development projects related to the cannabis, leafy greens, livestock, commercial cooling, aquaculture, and data center industries.

The Cultivation Classroom

Learn about the major choices of substrate, their benefits and disadvantages, the ways watering volume and frequency are affected by substrate choice, and more.

Rooting for Recapture and Reuse Impact of Substrate Choices on Irrigation Approach, Watering Rates, and Recirculation Activities

Ultrasonic processing, triple fractionation, and cannabinoids created without cannabis are just a few of the tech developments being explored.

Anyone following trends in the maturing cannabis industry can instantly see how products based on extractions—oils, edibles, vapes, infusions, and more—are becoming the biggest and most popular sellers.

In this “Tech Innovations” column, we explore what is driving more focus on extraction technology for cannabis, and the work being done to find solutions to certain issues that need to be addressed in extraction work, including bioavailability.

According to an industry data and research organization (1), annual legal sales of cannabis are projected to reach more than $41 billion by 2025, and feature strong demand for value-added products (that is, vapes, concentrates, edibles, and topicals) which have held their premium pricing better than flower.

Mining down into demographics, another industry report (2) found that Gen Z consumers consistently spend more on vapor pens than Baby Boomers. Gen Z consumers also increased their wallet share to vapor pens in 2020, whereas Baby Boomers drastically decreased theirs.

Edibles go the opposite way. Edible shares increased among Baby Boomers between 2019 and 2020, while it decreased among Gen Z consumers.

Cannabis consumers are becoming more interested in cannabis infused beverages as well, with purchases slowly ticking up through 2020 and into 2021 (3), in part because of a better tetrahydrocannabinol (THC) infusion process that, again, is related to new extraction technology about bioavailability.

“There is a trend towards extract dominance,” said Nick Tennant, founder and chief technology officer of Precision Extraction Solutions. “As we become more educated about multiple forms of ingesting cannabinoids, we see the trends shifting away from the consumption of flower. Flower is always going to have a place. The overall experience of that bud, the different colors and different aromas from that bud—it’s a very primal experience connecting us with something that the Earth made. But there is also a disruptive trend in that an extract has a more diverse ability to be consumed in multiple different ways.”

The evolution of extraction technology has been focused on better bioavailability of cannabinoids, and the elimination of less desirable and more harmful delivery methods such as smoking or vaping.

Other methods of delivery that help with the bioavailability of cannabinoids by circumventing metabolism (including sublingual, or below the tongue; transdermal patches; and topical sprays or creams) continue to be developed and are increasingly in demand by consumers.

The process for extracting oils from botanicals have a long history within the context of plant-derived medicine and supplement development (4). Using butane and propane became a preferred method of extraction for the cannabis industry early on.

One of the earliest closed-loop hydrocarbon extraction units for cannabis came from Extraction Tek Solutions in 2011. The company’s extraction system, the 1300, was able to do “about a kilo an hour,” according to Matthew Ellis, founder and CEO of Extraction Tek Solutions. “We got it peer-reviewed with an engineering service that allowed us to put it in use. It was one of the first licensable hydrocarbon units to do both butane and propane,” Ellis said.

Over the ensuing years, the company created both a mid-sized unit and a larger processing unit, addressing the challenges of hydrocarbon extraction. “The challenge is to be able to get the gas into the material and out of the material fast enough,” he said. “So being able to get 50 pounds or 100 pounds of gas in and out of the material is hard. That is one of the challenges we are facing. But we got some newer equipment we are working with and some newer pumps that allow us to do what we need to do.”

Newer systems are working on a wider array of products today. Orally ingested capsules containing THC derived through extraction also have their place on the menu of cannabis offerings. But that particular method of THC consumption creates lower bioavailability since it also requires processing in the gut, and requires a higher dose for the proper therapeutic effect, according to a research paper coauthored by Alexey Peshkovsky (4), cofounder, president, and chief scientific officer of Industrial Sonomechanics, a research and development, equipment design, and manufacturing company. The company specializes in scalable high intensity ultrasonic technology for liquid treatment, focusing on making nanoemulsions, nanocrystals, and liposomes for the pharmaceutical, cosmetic, medical cannabis, and food and beverage industries.

One better method of bioavailability is through this nanoemulsion process. According to Peshkovsky’s research, nanoemulsions are kinetically stable liquid-liquid dispersions of spherical droplets in which the dispersed phase droplet diameter is typically near or below 200 nm (a nanometer is 1 billionth of meter—a human hair is about 60,000 nanometers [5]).

Such small droplets have very high surface area-to-volume ratios, which promotes high surface tension at the water-oil interface. This increased surface tension, which is a property of liquid that allows it to resist an external force because of the cohesive nature of its molecules (6), coupled with small droplet diameter, steeply increases the pressure difference between the inside and the outside of the droplet surface, and represents an energy barrier that must be overcome to form nanoemulsions.

The research at Industrial Sonomechanics is focused mainly on making it possible to “mix things that don’t like to mix,” such as oil and water, according to Peshkovsky. “Everyone knows that oil doesn’t dissolve in water,” Peshkovsky said. “If you try to mix them no matter how vigorously, they will separate back out. And this is unfortunate because it’s difficult to infuse beverages with bioactive oils, which many substances happen to be. They’re oil compatible rather than water compatible, such as cannabis extracts. So this is what our technology is focused on.”

To make it possible to disperse oils in water in the form of nanometer-sized droplets—or nanoemulsions—a nanostabilizer process is used. The nanostabilizer process used at Industrial Sonomechanics is a proprietary all-in-one blend of ingredients needed to ultrasonically nano-emulsify hydrophobic bioactive extracts (including full- and broad-spectrum oils, distillates, isolates, vitamins, essential oils, terpenes, nutraceuticals, and pharmaceuticals).

It is comprised of food-grade carrier oils, emulsifiers, and preservatives, all tasteless and derived from natural sources. The process allows the operator to produce a cannabis extract nanoemulsion in water soluble powder form, that reconstitutes back into a liquid nanoemulsion upon contact with water.

Ultrasound in the machine passing through the liquid creates acoustic cavitation effects (7), which is the formation of vacuum bubbles in the liquid that first grow and then collapse. Those events happen at about 20,000 times per second. “When the vacuum bubble collapses onto itself, or implodes, it doesn’t do so symmetrically, and creates microjets or tiny micron sized jets that are very powerful,” Peshkovsky said. “They can hit droplets and break them into smaller particles. It’s a very typical technique for reducing the size of the particles.”

Using this ultrasound process, companies can produce such water-soluble powders from active ingredients such as cannabidiol (CBD) and Delta

-THC, which expands creative product offerings for the cannabis consumer. “Our technology is directly scalable so that you can scale it up to production, and we enable our clients to make their own nanoemulsions of CBD or THC in liquid or powder form in their own production environment,” said Peshkovsky. “This way you can expect to increase the bioavailability, make them act quicker, and make it possible to infuse beverages easily with them because they become compatible with water.”

Peshkovsky explained that the company has worked in the past with the pharmaceutical services industry on methods of drug delivery. But those drug developers didn’t need help in creating formulations. When the cannabis industry began asking him to help with creating formulas with their oils, at first they just offered advice.

“We just decided to develop an all-in-one solution that people could use and not have to develop their own formulations at all,” he said. “It’s a broad spectrum solution. If you have oil from your cannabis extract, you just mix it with the nanostabilizer, add some water, and run it through the machine. And you have the nanoemulsions. You don’t have to develop anything. You just follow standard operating procedures.”

He said that the operator doesn’t need to be a chemist to figure out how to understand the process and do the operation. “People want to do what they want to do. They want to create ideas, they want to create interesting original products, they want to brand them,” he said. “So we took all the guesswork out of it. We like to call it ‘science in a jar.’ So you follow the procedure. Mix cannabis oil with this nanostabilizer, add water through the machine that gets you a liquid nanoemulsion. If it’s done properly, it will be translucent so light can travel through it because the droplets are so small. Once you dose it into a water, let’s say, it goes completely transparent, it goes clear, you don’t see it, but you should be able to measure it with equipment.”

Another process gaining traction in extraction work is triple fractionation, which is the ability to drop certain compounds out into certain collectors according to their molecular weight, as explained by Jesse Turner, director of research and development for Green Mill, a CO

supercritical extraction system developer.

Triple fractionation is a process for extracting three oils at the same time, and collecting them into separate vessels using different extraction settings. “The way I will typically use it is separating, say, main cannabinoid fractions from terpene and hydrosol fractions (hydrosols are the process where plant constituents are evaporated into steam and then condensed into liquid form [8]),” said Turner. “Say you are running an extraction that is higher density because you want to get higher throughput, but you don’t want some of those heavier molecular weight compounds diluting down your cannabinoid extracts. You can set up the backend separation system to drop some of those heavy molecular weight compounds out while keeping your extraction as efficient as possible. It’s another tool in the toolbox that you have when you have a properly built CO

 system that allows you to kind of dice things up and do some unique things with it.”

The big project Turner and Green Mill are working on now is what Turner calls real-time winterization, he explained. Winterization is the process of removing compounds—such as fats, lipids, waxes, and chlorophyll—from the crude oil before the distillation process (9). Green Mill has developed a process where they can run their extractions, and during that process use a methodology that allows them to drop the waxes out during the process and collect wax-free extracts straight out of the system at the back end. Post-processing of the extract is either limited or completely unneeded.

Turner is also working on vapor pressure methods to massively increase solubility of THC and tetrahydrocannabinolic acid (THCA) in supercritical CO

 extractions by manipulating the vapor pressure rather than the solvent density.

Vapor pressure is achieved with the addition of heat to a closed extraction system to increase the volatility of compounds like cannabinoids. As these compounds get excited and volatilize, that increases the vapor pressure in the system. The increase in vapor pressure can be used to increase cannabinoid solubility (10). “We have had a lot of good results from that,” Turner said. “We have had initial extraction times cut down by a factor of four.”

 process is a little slower than a hydrocarbon extraction process, and takes more time with multiple passes as it’s processing. “Their run times are more like six hours,” he said. “And it’s a higher pressure so the cylinders used to contain that pressure are more expensive. Plus, with a hydrocarbon extraction process, you can come out with a smokable product. CO

 takes extra processing to refine it into vape pens and other products like that.”

Fritz Chess, the founder of Eden Labs, an extraction systems developer and one of the early pioneers in CO

 extraction technology for cannabis, said that there is a sort of second wave of psychoactive botanicals coming into play for extraction work, such as psilocybin. Psilocybin can be extracted from mushrooms using water, ethanol, or 200 proof ethyl alcohol as solvents, or through ultrasonic-assisted extraction (11).

“What is curious is that nobody is fighting psilocybin legalization,” said Chess. “When I was a kid, they told you that psychedelics would give you brain damage. Now they are saying by microdosing psilocybin, your brain is growing more neuronal connections and it actually makes you smarter.”

Chess explained that Eden Labs has designed a $30,000 cannabis extractor that can be used for mushrooms called the Coldfinger X (Eden Labs’ first extraction system, in 1993, was the Coldfinger system for ethanol extractions and distillation), which is known as the “goldilocks” unit because it is big enough to do small batch commercial operations and small enough for one person to operate (12).

Turner and Green Mill are thinking about psychedelics as well. Another ongoing project for Turner is to look into the extraction of difficult botanicals, such as compounds with higher molecular weight and higher polarity. “How can we take those and get faster and more efficient extractions out of it?” he said. “Whether it’s psychedelics in the future or any other of these other compounds of interest, it behooves the industry to start to try to think about and quantify how we would approach these different types of extractions outside of the cannabis industry.”

As extraction systems become smaller and easier to operate, it does not mean just anyone can operate them.

Like a handful of other extraction manufacturers working to make extraction systems smaller and versatile, Eden Labs makes both automated and manual extraction systems. But people wrongly believe that automated systems are easier to operate, according to Chess. “An automated unit doesn’t make the job any easier,” he said.

Chess has been a witness to the evolution of cannabis extraction. He is generally credited with creating the first supercritical CO

 extraction system for cannabis, which was used in a dispensary in San Francisco in the late 1990s. “The main work is grinding up all that herb, putting it in the vessel, getting it out of the vessel, timing the terpene run and cannabinoid run and all that,” he said. “You can program that to be done automatically. But the operator has to be able to run that and still have to tweak on everything.

“These guys that take the time to learn all the little nuances of running one of the machines and making exceptional product need to be treated better,” Chess said. “I see these extractor guys getting screwed over all of the time by investors and bosses. They bring them in and then think they can get rid of them three months later and hire another person for $15 an hour.”

It doesn’t necessarily take a chemist to do good CO

 extraction work, Chess added, just someone who is good with their hands and good with tools. “It could be a person who repairs air conditioners or fixes old cars or works on a farm and can learn to do this kind of work,” he said.

But there are tricks of the trade to learn. “Cannabis is kind of funny,” he said. “Different strains will behave almost like completely different herbs. So some of the techniques you can use that work reliably with other herbs, with cannabis it may or may not work from one strain to another. It just comes down for an extractor to know which strain he has and how it’s going to behave in his particular machine. There is a real art to it.”

Chess is working with a precision fermentation method for cannabinoids, where he would not be growing cannabis at all. “What is interesting about precision fermentation (a process of creating products with modified bacteria [13]), are the audacious claims that, by 2035, almost all food production will be converted over to precision fermentation, and everything we eat will be created that way,” he said. “Millions of acres of farmland can be turned back into forest, and the price of food production will be 1% of what it currently is.”

Indeed, precision fermentation for cannabis is being investigated by scientists in California and China who reported in a study (14) that they have engineered yeast strains capable of producing major cannabinoids found in cannabis from galactose, a simple sugar that has the same chemical formula as glucose (15). “Pending the identification of novel cannabinoid synthases, we expect to be able to produce a large fraction of this class of natural molecules. This work lays the foundation for the large-scale fermentation of cannabinoids, independent of cannabis cultivation, which will enable the pharmacological study of these highly promising compounds and ultimately new and better medicines,” the study concluded.

Extraction technology is all about isolating more and more cannabinoids in a repeatable process to provide a sort of tool chest of different cannabinoids to use with the endocannabinoid system. The envelope of innovation is continuing to be pushed in terms of methodologies to deliver these cannabinoids and compounds, explained Tennant. 

“There is a tremendous amount of innovation going on and we are just scratching the surface,” said Tennant. “Our line of sight (at Precision Extraction Solutions) is very much on isolation on a lot of these very unique and sought after cannabinoids, as well as the conversions with the isomers. I do believe that will be the future of a lot of things in cannabis. With that all said, the isolation of these molecules and their characterizations is not very easy. They all have very unique molecular structures. One thing I can tell you is that each molecule we isolate is unique, and that plays into how you extract it. I think you are seeing a really large push in cannabis because these are such high value molecules.”

It’s been reported that both cannabigerol (CBG) (16) and cannabinol (CBN) (17) isolates, for example, can bring about $30,000–50,000 dollars per kilo. “So it’s sort of who is going to get the pot of gold at the end of the rainbow,” Tennant said.

https://newfrontierdata.com/product/cannabis-in-america-for-2021-and-beyond/

https://www.headset.io/industry-reports/a-look-at-cannabis-demographics-consumer-behavior-in-2020

https://www.headset.io/industry-reports/cannabis-beverages-analyzing-category-brand-performance

https://info.sonomechanics.com/scalable_high-power_ultrasonic_technology_for_the_production_of_translucent_nanoemulsions-0?hsCtaTracking=38437c91-f759-4b97-9cfb-548c7660b276%7Cdc4c6f3b-45c4-4040-9388-1f79f3087c73

https://www.sciencedirect.com/science/article/pii/S1350417710002312

https://naha.org/explore-aromatherapy/about-aromatherapy/aromatherapy-extracts-produced-from-plants

https://precisionextraction.com/2020/06/what-is-the-winterization-process-in-cannabis-extraction/

https://www.greenmillsupercritical.com/extraction-glossary

https://www.hielscher.com/ultrasonic-cold-water-extraction-of-psilocybin.htm

https://www.edenlabs.com/coldfinger/coldfinger-benchtop/

https://www.theguardian.com/commentisfree/2020/jan/08/lab-grown-food-destroy-farming-save-planet

https://escholarship.org/content/qt3fn1m6p5/qt3fn1m6p5_noSplash_be06dd7b6fdfa004bec17ec4fed2cabd.pdf?t=qi5fd4

https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/galactose

https://acslabcannabis.com/blog/cannabinoids/a-guide-to-cbg-extraction-storage-price-consumption-and-more/

https://acslabcannabis.com/blog/cannabinoids/a-guide-to-cbn-should-you-be-emphasizing-cbn-in-your-hemp-and-cannabis-products/

 has written for many cannabis publications, and organized or moderated sessions at national and international cannabis trade shows. He was voted the 2018 Journalist of the Year by Americans for Safe Access, the world’s largest medical cannabis advocacy organization.

Tech Innovations

An exploration on what is driving more focus on extraction technology for cannabis, and the work being done to find solutions to certain issues that need to be addressed in extraction.

Better Gear, More Precise Processes Help Propel A Growing Range of Extraction Offerings 

The Maryland Medical Cannabis Commission (MMCC) recently began accepting applications for academic cannabis research licenses. For this installment of “Cannabis Crossroads,” I spoke with Rebecca Jackson who serves as an education and research analyst for the MMCC to discuss this new program and what the MMCC hopes to achieve with it. 

Rebecca, can you please tell us more about the MMCC’s academic research program and why it was created?

Cannabis policy continues to advance at a rapid pace, which has opened the door to discussions about funded medical cannabis research. Researchers want to evaluate the wide variety of cannabis products sold in states where cannabis is legal, but federal law prohibits them from doing so, since cannabis is still illegal at the federal level. This federal illegality hinders cannabis research, leaving medical providers and patients in the dark about the benefits and risks of cannabis products. The Maryland Medical Cannabis Commission (MMCC) has an important role to play in supporting scientific research and ensuring evidence-based data is used to form policy decisions. The Academic Research program was created with the intent of advancing scientific cannabis research by first removing certain barriers for researchers that make them wary to participate in the first place. House Bill 881 took effect on June 1, 2019, which established legal protections for academic research representatives in Maryland. An academic research representative purchasing medical cannabis in accordance with the bill and Maryland’s medical cannabis program is not subject to arrest, prosecution, civil or administrative penalties, including a civil penalty or disciplinary action by a professional licensing board, nor may they be denied any right or privilege, for the medical use or possession of medical cannabis. Additionally, academic research representatives may not purchase medical cannabis from any entity other than a Maryland licensed dispensary, meaning the medical cannabis being tested and researched in the MMCC Academic Research program is truly reflective of the medical cannabis products that are being produced, dispensed, and consumed by qualifying Marylanders.

This program could also foster new relationships and collaborations between industry and academia. Many local industries that develop technologies related to cannabis have been limited in their ability to research cannabis. Is this program limited to universities?

Academia is such an essential link to the advancement of cannabis science. At this time, the MMCC Academic Research program is limited to academic research institutions. This includes institutions of higher education, a related medical facility, or an affiliated biomedical research firm. An institution of higher education means an institution of post-secondary education lawfully operating in Maryland that generally limits enrollment to graduates of secondary schools, and awards degrees at the associate, baccalaureate, or graduate level. This includes public, independent, private nonprofit, and for-profit institutions of higher education. Academic research applications must include the name of the primary researcher at the academic institution, the expected duration of the research, and the primary objectives of the research.

On the MMCC website it appears that there is a $1000 registration fee as well as a $100 fee per research agent. Is this an annual fee? Are there any limitations or additional details that applicants should be
aware of?

There are no annual fees—the registration is valid for the term indicated and approved on the registration form. Registrants may apply for an extension of the registration beginning 90 days before the expiration of the registration. The registration remains valid unless there is a change in the research project, or the academic research institution withdraws the registration. Any prospective academic research representative may not be registered if they have ever been convicted of a felony drug offense. The MMCC, after review of the criminal history record information, may disqualify from registration any prospective academic research representative who is convicted of or pleads 

 to a crime involving moral turpitude, whether or not any appeal or other proceeding is pending to have the conviction or plea set aside.

 readers and potential applicants learn more about this new program? Who can they contact with questions?

Those interested in cannabis-related research are encouraged to visit the MMCC website (1) for more information on the Academic Research program. Information and applications can be completed for Academic Research Institution and Research Agent registration, renewal for subsequent or modified research project, and Research Agent identification card replacement. If you have any questions, please do not hesitate to contact Rebecca Jackson, Office of Policy and Government Affairs at 

Is there anything else that you would like to share about this program?

In the cannabis space, the lack of federal approval and oversight means that states have cannabis policies and products that vary considerably. In the absence of evidence-based data and clinical trials, most are left to rely on correlational data and testimonials to form decisions about medical cannabis consumption. Research is the only way to bring a clearer vision to the scientific world of cannabis and how it interacts with the human body. The MMCC is committed to encouraging the development of research programs and are always willing to provide support for researchers interested in conducting cannabis research. I am very excited to see what the coming years bring, and how cannabis policies can and will exponentially grow (pun intended), once reliable research can be performed in the United States. The Academic Research program is another way the Maryland Medical Cannabis Commission is furthering the possibilities of cannabis science and ensuring the overall goal—that medical cannabis is available to qualifying patients in a safe and effective manner.

In closing, I’d like to thank Rebecca and the MMCC for participating in this column and for their continued support of medical cannabis education and science. It has been a pleasure working with the MMCC on my Cannabis Science Conference events and I’m thrilled to announce that we’ll be bringing the conference back to the Baltimore Convention Center September 13–15, 2021. Hopefully Rebecca will be able to share some exciting updates about this program at the show. Visit 

https://mmcc.maryland.gov/Pages/home.aspx

 is the columnist and editor of “Cannabis Crossroads”
and a contributing editor to 

magazine. Crossney is also the president and CEO of Cannabis Science Conference. Direct correspondence to: 

Rebecca Jackson works in the Office of Policy and Government affairs at the Maryland Medical Cannabis Commission where she serves as the Education and Research Analyst.

Cannabis Crossroads

Rebecca Jackson discusses a new program at the Maryland Medical Cannabis Commission (MMCC) and what they hope to achieve with it.

Calling All Maryland Researchers:  MMCC Seeks Candidates to Apply for Academic Cannabis Research Licenses

This article series explores some of the more technical aspects of cannabis cultivation that growers should understand to run their businesses more efficiently and more profitably. Part II introduces vapor pressure deficit, a critical measurement of air conditions that impact the health and vitality of your plants. You've likely heard about this concept before, but it can be a difficult value to measure accurately—especially when most available information is oversimplified and can be misleading by extrapolating from estimations.

Imagine a pot of water put on a stove to boil with a heavy lid that has a few pinholes in it. Crank up the heat and eventually you will start to see thin streams of steam escaping through the holes. As pressure builds up in the pot, the rate at which steam escapes will continue to increase. Why doesn’t the steam just accumulate in the pot and rest on top of the water? The highly energetic state of water vapor (which is why it is hot, as discussed in our 

 [1]) needs to move from the highly concentrated vapor within the pot to the low concentration of vapor in the outside environment. This is an intrinsic property of water—it wants to disperse.

Steam is an extremely energetic state of water vapor, but liquid water does not have to boil to evaporate. When water absorbs enough energy from a conductive heat surface (stove), an intense light source (sun), or even sound (ultrasonic fog), it will eventually evaporate as individual molecules gain enough energy to be liberated from the pack. When water absorbs energy, it is taking energy from the environment and holding it within its molecule structure, resulting in a net cooling effect to the surroundings (or at least an inhibition of warming). On a sunny day, which would evaporate faster: a bucket full of water or a thin puddle of water? The high surface area of the puddle allows more molecules to be exposed to the sun’s energy, and therefore the puddle will evaporate faster.

This concept is exactly what happens inside of a plant that allows the leaf to stay turgid, or swollen, and able to keep itself cool.

Before diving deeper into how vapor pressure is relevant to plants, we need to understand how water gets into a plant to begin with.

From the seed stage, the root is the first thing to emerge because it can take up water on its own without requiring 

 which is the movement of water through a plant and out of
the leaves.

 The seed takes up water passively by osmosis as water moves from the wet environment (high concentration) into the dry seed (low concentration). This passive movement of water builds up pressure inside the root (radicle), cracking the seed open and forcing the seed and initial leaves (cotyledons) to stand up straight and emerge into the light.

Once the leaf is exposed to light, the process of transpiration begins and the root now has some help taking up water.

If the leaf emerged first without an already established stream of water, the vascular tissue would be full of air and would need a degassing valve just like in plumbing systems. This clearly isn’t an option, but transpiration through the leaves helps the root take up water. Plants are filled with a stream of water established by the initial root and if it is broken (drought), the plant will wilt or eventually die. For clones, this stream of water was established by the mother plant in the vascular tissue of the cutting. Think of water as separate from the plant and instead as a stream of fluid holding up the plant. It animates your plants, stands them upright, moves nutrients from the soil into respective plant organs, and allows them to take in light and CO

Roots maintain consistent water uptake by spending energy generated by root respiration to actively intake nutrients (nutrient concentration in the soil can amplify or weaken this effect). This process causes the solute concentration in the root cell to become higher than the rootzone, making water uptake happen naturally through osmosis (water follows solutes like nutrient salts or sugars). The cells surrounding vascular tissue in a plant are constantly spending high amounts of energy to pump into and remove solutes from the transpiration stream, forcing nutrients to enter the stream and deposit into various tissues throughout the plant.

The same thing happens in most developing leaf cells. After new cells are formed, plants spend energy to pump the new cell full of potassium, forcing water to enter by osmosis and stretch the cell walls. It takes a lot of pressure to make this happen—hydrostatic pressure in some plant cells has been measured as high as 300 psi. This pressure induces enzymes to loosen the cell walls, allowing them to slowly expand or grow. Roots alone can build up pressure around 30 psi, nearly as high as the tires on a car.

When the lights are on, transpiration drives most water uptake. In a developing plant, root pressure is generated primarily during dark periods when the transpiration rate is very low. The transpiration rate needs to be balanced with this pressure so that the plant can fill evenly with water and deposit nutrients consistently in both mature and developing tissues. This is important because mature leaves conduct far more water from the vascular system (xylem) since their pores (stomata) are typically larger and more mature. 

To control plant transpiration, we must introduce the term 

). This physical concept estimates the negative force pulling water vapor out of a leaf, allowing a stream of water to move up the plant stems from the roots. VPD is typically measured as the difference between the vapor pressure measurement in the substomatal pocket (the microscopically small pocket of air inside the leaf) and the vapor pressure measurement of the air surrounding the leaf.

If we looked inside a leaf pore (stomata), we would see large porous blobs (mesophyll cells) in the open air space where water vapor is being released and CO

 is entering from the space outside the leaf. We assume this “intercellular air space” is at near saturation of water vapor. Water makes up a small percentage of moist air and air has a maximum capacity for holding water (the capacity to hold water changes based on temperature as vapor molecules move faster or slower). These mesophyll, or “middle leaf” cells, are constantly releasing liquid water out of pores on the outer surface, which then spreads across the cell exterior like a puddle, thinning the layer of water and making it more likely to evaporate. This wet surface is also where CO

 dissolves and is then able to enter these photosynthetic cells and move into the chloroplast, where carbon capture occurs.

Because the intercellular air space in the leaf is nearly saturated with water vapor (meaning it cannot hold anymore) due to evaporation of water off the mesophyll cells, the air needs to move to an area with less water. The air outside of the leaf is usually below saturation, however there is a fascinating circumstance called 

 in which the leaf will exude droplets of water when there is low movement of vapor from the water surface coating the mesophyll cells due to a high vapor pressure outside of the leaf or low transpiration (almost exclusively during dark hours when root pressure is high).

As mentioned before, water moves from high concentration to low and its rate of movement is slowed when the vapor pressures inside and outside the leaf are close together. To determine VPD, we first estimate the vapor pressure within the leaf by using the saturation assumption paired with the leaf temperature. In other words, we quantify the internal vapor pressure as the maximum amount of water air can hold at the leaf temperature. We then subtract that value from the vapor pressure of the outside air at the measured water content (absolute humidity) and temperature, and then adjust for the atmospheric pressure where the plants are growing.

Plants Can Adapt to Shifting Vapor Pressures

If plants were inanimate objects, the concept of VPD would be fairly straightforward. However, plants have mechanisms to adapt to shifting vapor pressures in the atmosphere. Stomatal regulation is a key method in maintaining proper pressure within the plant to allow for growth. By modulating their aperture, plants can adapt fairly quickly to shifting conditions.

When a leaf is forming, the quantity and size of stomata on the leaves will reflect the environmental conditions present at development. If a species spends a long time in the same seasonal conditions, its genetic expression will be predicated on typical environmental conditions in addition to the current conditions, but when plants are grown indoors this concept does not help. We must determine what the conditions are that a varietal is prepared to handle, find the sweet spot and hold onto it. If you raise a plant in one set of conditions and then shift it into another, it will absolutely undergo stress trying to acclimate, slowing growth and reducing overall yield. If this is something that happens consistently, there can be tremendous growth inhibition and increased likelihood of pests (we will cover environmental uniformity and pest pressure further in a later article).

 refers to the amount of vapor or gas a plant’s pores can release and accept (opposite of stomatal resistance). Its value is measured in moles and is typically far higher than the actual transpiration rate because water composes such a small fraction of air. There are even more specific terms such as “gas phase conductance to CO

,” which is specific to the leaf’s ability to allow in CO

, or “mesophyll conductance,” which is specific to the ability of the internal cells to take in CO

 in the atmosphere directly impacts the concentration of CO

within the leaf and the stomatal aperture. When CO

 levels rise, the stomatal conductance drops, which does not change the VPD, but does reduce transpiration. VPD is a purely physical concept used as a method to anticipate a plant’s response to the environment, whereas stomatal conductance and transpiration measure biological functions of the plant.

Roots rely on a balance of soluble nutrients between the cells and the rootzone, and too high of a nutrient concentration (which can be tracked with electrical conductivity [EC]) can osmotically restrict the ability of a root to draw in water (solute potential). When this happens, the water supply to the leaf cell can be weakened, which will limit the amount of vapor that can be released into the leaf intercellular air space. This causes a slight wilting effect or even brown leaf tips, which will inhibit the ability of the plant to absorb light and overtime will be reflected in the amount of carbon captured and subsequent growth. Stomata will compensate for this stress to a degree, but that ability has limitations. This wilting effect also happens when plants are overwatered and the ability to access oxygen is restricted, which is necessary to maintain osmotic flow.

No matter what, if the plant is coping with stress, yield will be reduced. Think of a human sprinting or running—the lungs and body will alter their function to make that task possible, but once the extra energy runs out, the body must slow down and recharge. In the case of plants, they can’t slow down because they are controlled by their environment, so instead they will die.

The next article in this series will continue the discussion of VPD in the context of how light spectrum impacts transpiration.

 is a passionate engineer with more than a decade of experience designing, selling, and commissioning HVAC and process systems throughout North America. Recognizing that there is a knowledge gap around fully understanding plant transpiration rates and how they impact controlled environments, he co-founded 

 to focus on advanced transpiration solutions. 

 is a solution-oriented, “big picture” researcher focused on finding the balance of production variables to optimize plant-growth and facility operations without sacrificing quality. He comes from an eclectic horticultural background spanning topics such as sustainable agriculture, vertical farming, Cannabis cultivation and food production on the International Space Station. Sam holds a BSA and MS in Horticulture and currently works as a crop science consultant while pursuing his PhD in cannabis cultivation.

Feature

Learn more about vapor pressure deficit and how it is a critical measurement of air conditions that impact the health and vitality of your plants.

May 2021

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Calling All Maryland Researchers: MMCC Seeks Candidates to Apply for Academic Cannabis Research Licenses

A Deep Dive into Vapor Pressure Deficit for Commercial Cannabis Cultivation

New Age Artificial Intelligence for Cannabis Production?

There’s a Surplus of Hemp in the Market: What Happens in 2021?

The Power of Synthetic Cannabinoids and Why Big Pharma Prefers Them