By John Brunstein
31 Mar 2016
Why is keeping pathogens like moulds, fungi, and bacteria out of a growing facility so important? Don’t plants normally just grow “out in the wild”, with all of those naturally occurring?
Let’s explore the question…
Plants growing in natural, uncultivated environments are generally at relatively low density (mixed in with other plants) and subject to constantly changing conditions of temperature and humidity. Pathogens have preferred growth conditions, and this variable environment means that much of the time it’s not optimal for pathogen growth. This slows pathogen replication, and when combined with an environment containing a range of plants – many of which will not be good hosts for a specific pathogen – the result is that on the whole, pathogens survive but they don’t grow very rapidly, and they don’t infect and damage large numbers of host plants.
By contrast, if you grow monoculture (that is, a single uniform plant species) and in a controlled, highly uniform environment, then if you get a pathogen introduced which can live on the plants being grown, it will rapidly adapt to that environment, grow very quickly, and easily spread. Since these are the conditions you need if you want to grow uniform, high quality plants, it’s just an unfortunate coincidence that you now have a system which is much more susceptible to plant infection by pathogens than in a less controlled, more diverse environment. In a nutshell, uniform great growing conditions for your plant are also always going to be uniform great growing conditions for some pathogen that can attack that plant.
We don’t want pathogens on the plants. Why? One answer of course is that some pathogens make the plants sick, or even kill them. However, even pathogens which don’t outright kill the plants can cause bad effects. Moulds and fungi can leave aflatoxins (highly potent carcinogens) behind; bacteria can leave bacterial endotoxins (molecules which can cause unwanted immune system reactions if we’re exposed to them) behind; both kinds of pathogens can leave molecules behind which can trigger allergic responses in sensitive individuals; and aspects of product quality including smell and texture can be negatively impacted by presence of plant pathogens. Also, many plants will sense and react to the presence of pathogens by changing what metabolites (small molecules) they produce. If you’re culturing something like Cannabis where small molecules are the desired product, that’s an unwanted source of variability! Finally, depending on how the plant is processed and used after harvesting, it’s even possible that the pathogens on the plant can lead to infections in people with weakened immune systems – although since most plant pathogens don’t infect people, and most people aren’t immunocompromised, this is probably the least significant risk. Taken together, all of the above demonstrate that pathogens on the plants are both a risk for production quality and yield, and can be a health risk to the end consumer of harvested plants.
So now we understand why indoors, high yield / high quality growth conditions are susceptible to pathogen infection, and why we don’t want that to occur; the question remains, how to defend against these unwanted moulds, fungi, and bacteria? The first option – and one used in many forms of large scale agriculture – is to reach for pesticides (we’ll use that term generically here to cover chemical treatments used to suppress not just insect pests, but also moulds, fungi, and unwanted bacteria). Why doesn’t Segra just opt for this?
Figure 1: Pesticides can be very harmful to humans.
In the Canadian “Marihuana for Medical Purposes Regulations” (MMPR) jurisdiction, it’s a simple answer – we’re not legally allowed to! Health Canada prohibits the use of almost all pesticides; they do this because use of pesticides in Cannabis cultivation is seen as having significant risk to end product users. These risks arise because pesticides (and particularly many of those used for mould, fungus, or bacterial suppression) are poisonous to varying degrees to people as well as microbes. While rare, very small scale exposure to pesticide traces won’t probably cause measurable harm to a person, recurring exposure (like in taking a medical or consumer product on a regular basis) can lead to progressive accumulation of these toxic chemicals in the user. If the Cannabis is used for smoking, an additional complication is that the act of burning the pesticide residues can lead to chemical changes in the compounds; what these changes are, the exact nature of the compounds formed, and their effects aren’t well known. As a general rule, it’s a bad idea to willingly expose yourself to unknown chemicals. In the case of extracts, the extraction process itself can lead to the concentration of trace quantities of pesticide residues to significantly higher levels. If you combine extracts and smoking, you’ve now got the worst of both worlds. So, under MMPR rules, no traditional pesticides are allowed to be used, and every single product lot must be tested for – and show no traces of – more than 60 pesticides.
In other jurisdictions, pesticide usage is allowed in Cannabis culture. Worse, some of these same jurisdictions don’t require testing of all product lots prior to sale. Regardless of what the law allows in these jurisdictions, for all of the risks described above, Segra’s approach is to not use pesticides for the suppression of pathogens – and our Standard Operating Protocols (SOPs) call for testing of every production lot, whether that’s legally mandated or not. This commitment to safety and quality is the hallmark of a Segra Biogen product, and one we believe our customers appreciate and understand.
If Segra won’t use pesticides in its production, and we’ve established that pathogens are a risk, what then can we do to minimize that risk? The best strategy left to us is one of “3 Cs”: Cleanliness, Containment, and Conformity. We ensure that all raw materials are properly “Cleaned” before going into the grow spaces, and we have extensive protocols for the cleaning and gowning of all staff going into grow areas. Our grow facility building designs include extensive, well thought out features to “Contain” clean materials in clean environments, and not have crossover from uncontrolled material which could be a possible source of pathogen entry. Finally, we ensure “Conformity” to all of the processes and protocols needed to carry out “Cleanliness” and “Containment”, through having a fully developed Quality System and ensuring all staff are appropriately trained in “Conforming” to all SOPs.
So there you have it – that’s why access control and extensive steps to isolate ‘Clean’ plant growing areas from the rest of the facility are so important to Segra’s way of production, and how that translates into our products being the best quality, uniformity, and safety you can get.