Hashing Out the Effects of Silicon on Cannabis
Cannabis growers are always looking to boost bud yield as well as protect it from the concerns of diseases and heavy metals. Here, we chat with Dr. Shiv Reddy—who holds a patent on silicon embedded growing media—on the science of how silicon can improve cannabis plant yield and health.
Maximum Yield: Is silicon important for cannabis?
Shiv Reddy: Yes, there is solid scientific basis for giving silicon to any plant, but especially to cannabis plants, especially when you’re growing in container or potting mixes, which naturally don’t have silicon. As you may know, the cannabis plant produces the cannabinoid compounds THC, CBD, etc. in hair-like structures called trichomes, which are mostly on the flower buds. Basically, these trichomes are your little chemical factories producing your end product. As you would suspect, more and large trichome factories yield more cannabinoids. University of British Columbia research confirmed this too. So, how do you enhance your trichome factories?
University of California professor Emanuel Epstein—I think was the first—to observe that plants produce strong trichomes when you give silicon. Plants transport silicon given to the roots, from roots to trichomes and solidify that silicon in and around trichomes, to make their trichomes strong and tough. Without silicon, trichomes tend to be smooth and weak. Since Epstein’s observation, more and more researchers observed and described the effects of silicon as: plants given silicon produce more trichomes, high density trichomes, longer trichomes, rigid trichomes, pronounced trichomes, distinct trichomes, strongly developed trichomes, etc.—overall just better trichomes.
MY: So, would these silicon-solidified trichomes actually yield more medical compounds?
SR: Indeed, Brazilian researchers found out just that in the Artemisia plant. Artemisia is like a sister plant to cannabis, in the sense that Artemisia also produces a chemical compound artemisinin in its trichomes. Artemisinin is used to treat malaria. The researchers found that when you give silicon, trichomes are bigger plus all the trichomes remained intact, thus yielding more artemisinin compound. Without silicon, trichomes shrivel, collapse, rupture open, yielding less of the compound.
MY: By the way, why are these trichomes on plants? Why do they produce these compounds?
SR: Plants have trichomes to protect themselves against bugs, frost, UV light, etc. Imagine an insect or fungal spore trying to land on your skin. If your skin has hairs—just like trichomes—and the hairs are strong and sharp, it’s difficult for the bug to reach your skin, right? Plants produce chemical compounds in trichomes as another level of defense—a chemical defense to deter the bugs reaching the plant skin—perhaps by stoning the bugs!
MY: Talking of plant protection, you know there are limitations on using pesticides on cannabis. Would strong trichomes or silicon in anyway help in protecting cannabis plants?
humidity and warm temperature within the canopy — a thriving combination for pathogens such as powdery mildew. The bushy canopy also makes it hard to detect the disease early on, especially under the glare of grow lights.SR: Even if pesticides are available for use on cannabis, consumers wouldn’t want to consume a cannabis product tainted with pesticides, right? If you look at cannabis plant, you see a plant growing profusely with dense foliage. Such bushy canopy leads to high
As you know, powdery mildew is a dreaded disease in cannabis. Though powdery mildew doesn’t kill the plant, the disease causes serious damage and makes the plant weak. There is lot of research—convincing research—showing silicon reduces severity of several diseases, especially powdery mildew. Silicon reduces the severity of diseases by reinforcing the epidermis or plant skin, so the reinforced epidermis acts as a shield against fungal penetration. And, as professor Belanger’s research group in Canada found, when silicon is available to plants while the pathogen is infecting, plants produce compounds that defend that infection.
MY: As you know, heavy metals are a big concern in cannabis. You hear that silicon helps in this heavy metal concern. How?
SR: Heavy metal and cannabis don’t rhyme, do they? Yes, since cannabis is consumed by people, growers are concerned about their end product failing the heavy metals test. Rightly so, as the cannabis plant is a hyper-accumulator of heavy metals. In fact, cannabis plants were used to clean up heavy metals in soils at Chernobyl disaster site! Unfortunately, that natural ability of cannabis plant to suck up heavy metals can also occur in your growing due to any heavy metals present in weird compost or organic fertilizer that you may be using inadvertently. Silicon reduces such heavy metal absorption by plants. How? Silicon binds metals outside in the soil, thereby reducing the metals available for plant absorption. Silicon also binds and retains metals in the root, thus decreasing their transport to the shoots. Final result is reduced heavy metals in your end product at the top.
MY: Is there any other effect of silicon on cannabis?
SR: Recently, Belgian researchers found that when you give silicon to hemp cannabis seeds, you see higher germination rate and vigorous seedlings. The hemp seeds imbibe silicon and that silicon stimulates and strengthens hypocotyl. As you may know, a strong hypocotyl translates to a strong stem in the seedling, thus giving a strong start in growing. The strong, thick stems due to silicon also help cannabis plants to hold big, heavy colas upright during flowering.
MY: With so many benefits, is there any downside to using silicon?
SR: Luckily, silicon has a very good safety profile. Silicon is not toxic to the plants or the environment. Silicon is compatible with your normal growing practices. Silicon is even compatible with organic growing. Silicon is inexpensive too, so even if you don’t see all silicon effects or see just one silicon effect, it would still be worth it. As USDA researcher Dr. Frantz aptly put—one should rather have silicon than not in their production system—especially in cannabis production. By integrating such simple, science based silicon use into your production system, you could produce less disease plants and more cannabinoids and a little more profit.
Written by Shiv Reddy | Tech
Dr. Shiv Reddy is a grower services specialist focusing on cannabis at Sun Gro Horticulture company.