As the cannabis industry in the United States and throughout the world develops, the market is getting more competitive. Markets in a number of states are experiencing disruptions that will have lasting effects for cultivators, including oversupply and supply chain bottlenecks. Now more than ever, growers need to look for ways to differentiate their product or gain a bigger market share. Looking at yield efficiency, quality improvements and analyzing the cost of inputs versus value of the crop can help growers make the right choices in technology for lighting, irrigation and pest control among other technologies.
A series of free webinars in two weeks can help growers learn about some of the more advanced techniques in improving yield and quality. The Cannabis Cultivation Virtual Conference on May 23rd will explore a variety of tips and tricks for taking their cultivation operation to the next level. This event is free to attendees, made possible by sponsors VividGro and CannaGrow Expo.
Attendees will hear from experts in cannabis cultivation on a range of topics, including breeding, drying, curing, environmental monitoring and micropropagation. Adam Jacques, co-founder of Growers’ Guild Gardens and Sproutly, will discuss some of his experience with breeding high-CBD strains in Oregon. His talk will delve into some of the proper breeding procedures, along with how to hunt for particular phenotypes and developing specific cannabinoids and terpenes.
Dr. Allison Justice, vice president of cultivation at Outco, is going to present some of her findings in drying and curing at the company. She plans on sharing her research on how the post-harvest stages can affect and control the chemical makeup of flower. She’ll also discuss some new protocols to monitor the dry and cure of cannabis flowers so we are able to modulate the terpene and cannabinoid profiles.
The technology portfolio, aimed at larger, commercial-scale growers, is essentially a network of monitors, sensors and controls that give cultivators real-time data on things like temperature, humidity, light, barometric pressure and other key factors. The idea of using IoT and hypersensitive monitoring is not new to horticulture, food or agriculture, but this is certainly a very new development for the cannabis growing space.
According to Brad Nattrass, chief executive officer and co-founder of urban-gro, it’s technology like this that’ll help growers control microclimates, helping them make the minor adjustments needed to ultimately improve yield and quality. “As ROI and optimized yields become increasingly important for commercial cultivators, the need for technologies that deliver rich granular data and real-time insights becomes critical,” says Nattrass. “With the ability to comprehensively sense, monitor, and control the microclimates throughout your facility in real-time, cultivators will be able to make proactive decisions to maximize yields.”
One of the more exciting aspects of this platform is the integration of sensors, and controls with automation. With the system monitoring and controlling fertigation, lighting and climate, it can detect when conditions are not ideal, which gives a cultivator valuable insights for directing pest management or HVAC decisions, according to Dan Droller, vice president of corporate development with urban-gro. “As we add more data, for example, adding alerts for when temperatures falls or humidity spikes can tell a grower to be on the lookout for powdery mildew,” says Droller. “We saw a corner of a bench get hot in the system’s monitoring, based on predefined alerts, which told us a bench fan was broken.” Hooking up a lot of these nodes and sensors with IoT and their platform allows the grower to get real-time monitoring on the entire operation, from anywhere with an Internet connection.
Droller says using more and more sensors creates super high-density data, which translates to being able to see a problem quickly and regroup on the fly. “Cannabis growers need to maintain ideal conditions, usually they do that with a handful of sensors right now,” says Droller. “They get peace of mind based on two or three sensors sending data points back. Our technology scales to the plant and bench level, connecting all of the aggregate data in one automated system.”
In the future, urban-gro is anticipating this will lay the groundwork for using artificial intelligence to learn when controls need to be adjusted based on the monitoring. Droller hopes to see the data from environmental conditions mapped with yield and by strain type, which could allow for ultra-precise breeding based on environmental conditions. “As we add more and more data and develop the platform further, we can deliver some elements of AI in the future, with increased controls and more scientific data,” says Droller.
Many physicians today treat their patients with cannabidiol (CBD, Figure 1), a cannabinoid found in cannabis. CBD is more efficacious over traditional medications, and unlike delta-9 tetrahydrocannbinol (THC), the main psychoactive compound in cannabis, CBD has no psychoactive effects. Researchers have found CBD to be an effective treatment for conditions such as cancer pain, spasticity in multiple sclerosis, and Dravet Syndrome, a form of epilepsy.
Most manufacturers use chromatography techniques such as high performance liquid chromatography (HPLC) or flash chromatography to isolate compounds from natural product extracts. While these methods are effective for other applications, they are not, however, ideal for CBD isolate production. Crude cannabis oil contains some 400 potentially active compounds and requires pre-treatment prior to traditional chromatography purification. Both HPLC and flash chromatography also require silica resin, an expensive consumable that must be replaced once it is contaminated due to irreversible absorption of compounds from the cannabis extract. All of these factors limit the production capacity for CBD manufacturers.
Additionally, these chromatography methods use large quantities of solvents to elute natural compounds, which negatively impacts the environment.
A Superior Chromatography Method
Centrifugal partition chromatography (CPC) is an alternative chromatography method that can help commercial CBD manufacturers produce greater quantities of pure CBD more quickly and cleanly, using fewer materials and generating less toxic waste. CPC is a highly scalable CBD production process that is environmentally and economically sustainable.
The mechanics of a CPC run are analogous to the mechanics of a standard elution using a traditional chromatography column. While HPLC, for instance, involves eluting cannabis oil through a resin-packed chromatography column, CPC instead elutes the oil through a series of cells embedded into a stack of rotating disks. These cells contain a liquid stationary phase composed of a commonly used fluid such as water, methanol, or heptane, which is held in place by a centrifugal force. A liquid mobile phase migrates from cell to cell as the stacked disks spin. Compounds with greater affinity to the mobile phase are not retained by the stationary phase and pass through the column faster, whereas compounds with a greater affinity to the stationary phase are retained and pass through the column slower, thereby distributing themselves in separate cells (Figure 2).
A chemist can choose a biphasic solvent system that will optimize the separation of a target compound such as CBD to extract relatively pure CBD from a cannabis extract in one step. In one small-scale study, researchers injected five grams of crude cannabis oil low in CBD content into a CPC system and obtained 205 milligrams of over 95% pure CBD in 10 minutes.
The solvents used in chromatography, such as methanol and acetonitrile, are toxic to both humans and the environment. Many environmentally-conscious companies have attempted to replace these toxic solvents with greener alternatives, but these may come with drawbacks. The standard, toxic solvents are so common because they are integral for optimizing purity. Replacing a solvent with an alternative could, therefore, diminish purity and yield. Consequently, a chemist may need to perform additional steps to achieve the same quality and quantity achievable with a toxic solvent. This produces more waste, offsetting the original intent of using the green solvent.
CPC uses the same solvents as traditional chromatography, but it uses them in smaller quantities. Furthermore, as previously mentioned, these solvents can be reused. Hence, the method is effective, more environmentally-friendly, andeconomically feasible.
CPC’s Value in CBD Production
As manufacturers seek to produce larger quantities of pure CBD to meet the demand of patients and physicians, they will need to integrate CPC into their purification workflows. Since CPC produces a relativelyduct on a larger scale, it is equipped to handle the high-volume needs of a large manufacturer. Additionally, because it extracts more CBD from a given volume of raw cannabis extract, and does not use costly silica or require multiple replacement columns, CPC also makes the process of industrial-scale CBD production economically sustainable. Since it also uses significantly less solvent than traditional chromatography, CPC makes it financially feasible to make the process of producing CBD more environmentally-friendly.
Plants and animals have roughly 25,000 to 30,000 genes. The genes provide the information needed to make a protein, and proteins are the building blocks for all biological organisms. An ideal analogy is a blueprint (DNA) for an alternator (the protein) in a car (the plant). Proteins are the ‘parts’ for living things. Some proteins will work better than others, leading to visible differences that we call phenotypes.
Many traits, and the genes controlling them, are of interest to the cannabis industry. For hemp seed oil, quality, quantity and content can be manipulated through breeding natural genetic variants. Hemp fibers are already some of the best in nature, due to their length and strength. Finding the genes and proteins responsible for elongating the fibers can allow for the breeding of hemp for even longer fibers. In cannabis, the two most popular genes are THCA and CBDA synthases. There are currently over 100 sequences of the THCAS/CBDAS genes, and many natural DNA variations are known. We can make a family tree using just the THCAS, gene data and identify ‘branches’ that result in high, low or intermediate THCA levels. Generally most of the DNA changes have little to no effect on the gene, but some of the changes can have profound effects.
In fact, CBDAS and THCAS are related, in other words, they have a common ancestor. At some point the gene went through changes that resulted in the protein producing CDBA, or THCA or both. This is further supported by the fact that certain CBDAS can produce some THCA, and vice-versa. Studies into the THCAS and CBDAS family are ongoing and extensive, with terpene synthase genes following close behind.
Identifying gene (genetic) variants and characterizing their biological function allows us to combine certain genes in specific combinations to maximize yield, but determining which genes are important (gene discovery) is the first step to utilizing marker-assisted breeding.
Gene Discovery & Manipulation
The term genetics is often misused in the cannabis industry. Genetics is actually “the study of heredity and the variation of inherited characteristics.” When people say they have good genetics, what they really mean is that they have good strains, presumably with good gene variants. When people begin to cross or stabilize strains, they are performing genetic manipulation.
A geneticist will observe or measure two strains of interest, for example a plant branching and myrcene production. The high-myrcene plant is tall and skinny with no branching, reducing the yield. Crossing the two strains will produce F1 hybrid seeds. In some cases, F1 hybrids create unique desirable phenotypes (synergy) and the breeder’s work is completed. More often, traits act additively, thus we would expect the F1 to be of medium branching and medium myrcene production, a value between that of the values recorded for the parents (additive). Crossing F1 plants will produce an F2 population. An F2 population is comprised of the genes from both parents all mixed up. In this case we would expect the F2 progeny to have many different phenotypes. In our example, 25% of the plants would branch like parent A, and 25% of the F2 plants will have high myrcene like parent B. To get a plant with good branching and high myrcene, we predict that 6.25% (25% x 25%) of the F2 plants would have the correct combination.
The above-described scenario is how geneticists assign gene function, or generally called gene discovery. When the gene for height or branching is identified, it can now be tracked at the DNA level versus the phenotype level. In the above example, 93.5% of your F2 plants can be discarded, there is no need to grow them all to maturity and measure all of their phenotypes.
The most widely used method for gene discovery using natural genetic variation is by quantitative trait loci mapping (QTL). For these types of experiments, hundreds of plants are grown, phenotyped and genotyped and the data is statistically analyzed for correlations between genes (genotype) and traits (phenotype; figure). For example, all high-myrcene F2 plants will have one gene in common responsible for high myrcene, while all the other genes in those F2 plants will be randomly distributed, thus explaining the need for robust statistics. In this scenario, a gene conferring increased myrcene production has been discovered and can now be incorporated into an efficient marker-assisted breeding program to rapidly increase myrcene production in other desirable strains.