From Test Tubes to High Yields: The Future of Cannabis Cultivation

Cannabis cultivators require a reproducible, clean growing process to meet high demand while producing a consistent product.

Enter large-scale, plant tissue culture propagation. Plant cells are harvested from the mother plant, grown under sterile conditions using hormones and nutrients in a medium nutrient, following practices adopted from orchid cultivation.

It's far from a country farm. The process of tissue culture involves test tubes, sterile laboratories, and technicians in clean suits. Cannabis is one crop that's used to artificial conditions. Tissue culture offers a lot for growers looking for disease-free, vigorous plants.

It's not an easy or cheap process. We'll discuss the process and its pros and cons.

What Is Tissue Culture?

The tissue culture process is divided into four steps.

1. Initiation. Explants are small pieces of plant tissue that have been cut from the mother plants, sterilized using antimicrobial chemicals and then placed on a jelly containing plant hormones and nutrients. The hormones cause the plant tissue cells to divide quickly, resulting in a mass of cells that is called a callus.
2. Root Formation. After the callus has developed roots, it is transferred to a jelly that contains plant hormones which stimulates the callus. This callus containing roots is then placed in a jelly that contains different hormones for stimulating the growth of new shoots.
3. Plantlets are formed. A callus with roots and sprouts separates to form tiny plantlets. This way, a small number of original plant cells can be multiplied into many tiny plantlets.
4. Transferring plantlets. After the plantlets reach a height between 5-6 inches they are hardened, and then transferred into soil. Plantlets are hardened under low light and high humidities. By hardening the plantlets, they are better equipped to withstand harsh environments outside of the lab.

Tissue culture has many advantages

Why would this method be preferred to the conventional methods of cloning marijuana? There are many advantages:

• Infected cells can be cleaned to become clean stock.
• The plants that result are healthier, more vigorous and pest-free. They also produce higher yields.
• The initial steps are easier to accomplish than with traditional growing because they don't require pollinators or seeds.
• Tissue-cultured plants, like clones, are all female. There is no need to remove rogue males.

This process produces less waste. Fred Green, an horticulturalist in Princeton, Massachusetts says that "eliminating mother rooms reduces water consumption because the plants don't need to be kept alive." In terms of energy consumption, the number of watts required per square foot for tissue culture is a fraction of that needed to keep mother plants healthy and growing.

The space needed for clones, mother plants and seeds is much less. In an average facility, 15-17% space is devoted to mother plants and vegging-clones. Green said that if you use tissue cultures, "almost all of it can be converted to flower production."

Tissue Culture Has Its Disadvantages

Tissue culture is a long and difficult process. The plants grown in the lab cannot be immediately transplanted into a greenhouse.

The cost of setting up a tissue-culture operation can be in the hundreds of thousands. In the current market, most producers lack training. It is expensive to build clean rooms and to run them. They also require special equipment that filters the air in order to reduce contamination.

In the early stages of their life, plants grown by tissue culture are more susceptible to disease. Spores and bugs can wipe out an entire crop in a matter of minutes. Green says that "all tools must be sterilized after each use." You can be sure that if you touch 20 plants after a spore of disease has been transferred to a tweezer, they will all have the disease.

Plantlets are fast growing, but putting new crops into a program of clean stock can take many years. It takes six to nine months to clean up and stabilize a strain before it can be put into production. Then, it can take many years before the strain is ready for large-scale production.

In marketing for tissue culture, it is often claimed that the plants are disease and pest free from the start. Jeremy Plumb is the Director of Production Science for Pruf Cultivar, in Oregon. He says that this is only the start of the journey. It is still necessary to have good growers, a stable environment, and the ability to control temperature and other factors such as lighting, humidity, nutrients and others. Plumb said that unless you are able to control these variables, tissue culture will not make a difference.

Waiting For Market Expansion

Currently, only a few US companies are embracing the tissue culture. The legal market is young, and many businesses are still learning how to do things.

California could be the exception. Because the market is so small at the state-level, this practice is not viable. Green believes that only a few cannabis growers use this process in the US, but Canada has a legal market for the entire country. "Canada is far ahead of the US, because it's possible to ship anywhere within the country."

You may want to put off your high-tech dreams until the market grows.