PGR’s… It is a term you hear more and more as cannabis users, but what are they, why do they exist and what is it all about? In this blog, we will try to answer those questions for you.
What are they?
Plant growth regulators, also known as plant hormone boosters or plant growth regulators, are synthetic or naturally occurring compounds that regulate various aspects of plant growth and development. They play a crucial role in plant physiology and are used in agriculture, horticulture and plant research. Over the years, PGRs have become part of our daily lives. We consume them much more than we think. Below I have listed the main applications for PGRs….
1. Seed germination: Plant growth regulators can be used to promote or inhibit seed germination. For example, gibberellic acid is often used to break germination dormancy and promote germination in some plant species.
2. Root development: plant growth regulators can stimulate root growth and development. Auxins, such as indole-3-acetic acid (IAA), are often used to promote root formation in cuttings during vegetative propagation.
3. Stem extension: Plant growth regulators can control stem extension. Gibberellins are often used in commercial horticulture to cause stem elongation in certain crops, such as grapes or certain ornamental plants.
4. Fruit development: plant growth regulators can influence fruit development, size and ripening. Ethylene, for example, is a hormone involved in fruit ripening, and its application can enhance or delay fruit ripening, depending on the desired result.
5. Flowering: plant growth regulators can be used to manipulate flowering. For example, synthetic auxins may be used in some plants to induce flowering, while other hormones such as cytokinins may delay or prevent flowering.
6. Fruit thinning: Plant growth regulators can be used to thin fruit clusters or excess fruit load on trees. This practice helps improve fruit size, quality and overall yield.
7. Plant height control: Plant growth regulators are often used to control plant height in ornamental plants and crops. By inhibiting gibberellin biosynthesis or promoting ethylene synthesis, excessive stem elongation can be prevented.
8. Stress response: plant growth regulators can help plants cope with various environmental stresses, such as drought, salinity or extreme temperatures. They can increase the plant’s ability to tolerate and recover from stress conditions.
9. Weed control: Plant growth regulators can be used as herbicides to control weed growth. Synthetic auxins, such as 2,4-D or dicamba, are often used in selective herbicides to control broadleaf weeds in crop fields.
The more technically minded want to realize when reading the above list that PGRs work on plant hormones or mimic them, and when we apply PGRs to plants, we effectively manipulate how they grow.
Why do they exist?
So why do we feel the need to manipulate our plants? Well, unfortunately, we as humans are to blame. The development of PGR began in the food industry. There was a time, before PGRs (and for reference you can check out an organic market) when fruits and vegetables were not so uniform in size and color. For example, let’s look at our everyday tomato.
Today we have about 20 different types of tomatoes to choose from. The varieties vary in size, color and taste. But for the modern food industry, a “standard” has been defined for individual types. The standard defines size, color and shape. This is done for three main reasons – to help the plant become more resistant to pests and diseases, to simplify packaging and transportation, but also because we, as buying customers, have become very critical of the appearance of our fruits and vegetables. We will choose only the finest examples, leaving behind the unfinished or bruised ones. As a result, supermarkets only want to buy near-perfect examples from suppliers. So growers have been forced into this standardization in a way for economic reasons.
However, you will find that very few tomatoes that we actually buy have a rich tomato flavor, but more than often are, quite tasteless. This is because of the PGRs that have been applied. Here, PGRs are used to speed up growth time and produce a harvestable fruit sooner, to force uniformity in the crop and to make the fruit more aesthetically pleasing. The plants’ natural energy that would normally be used to develop flavor has been redirected to stimulate hormone production, which in turn speeds up the growth process, gives the tomatoes a deeper color and promotes uniformity.
However, if you visit an organic market, you will find fruits and vegetables that are much less uniform in size and shape – but the taste and smell are almost always present, and stronger than you would experience in a non-organic supermarket.
We can apply the same trend above to the cannabis industry. As consumers, most of us want the finest buds with the highest cannabinoid levels. Growers use feed and boosters to create more resistant plants that produce sturdier, stronger flowers. There are numerous different compounds used for this purpose, with the majority also manipulating hormone production. Although most of these compounds are perfectly safe to use and have no (known) health effects, when used in excess they often have a negative effect on terpene production. Most of us will have experienced a nice, compact bud, but with very little aroma. This is the result of applying excessive PGRs.
The vast majority of PGRs used in the industry are safe to use and consume. Some are harmful to us. These are already banned in many countries worldwide (including the EU), but as the cannabis industry largely unregulated, and occasionally these PGRs are still used.
So what are the health risks?
The health risks associated with the use of synthetic plant growth regulators in cannabis cultivation can vary depending on the specific chemical and level of exposure. While I can provide some general information about possible health risks, it is important to note that scientific research on the specific effects of PGR use in cannabis is limited. Here are some potential health risks associated with the more dangerous compounds found in PGRs. These are the compounds that matter most when testing on PGRs
1. Paclobutrazol: Long-term exposure to paclobutrazol may pose health risks. Animal studies have shown that paclobutrazol can affect hormone levels and reproductive function. It is classified as a potential endocrine disruptor and may have adverse effects on human development and fertility. Moreover, inhaling or ingesting paclobutrazol residues on cannabis plants treated with this chemical can be harmful.
2. Daminozide (Alar): Daminozide was banned for use on food crops because of concerns about its potential carcinogenicity. It has been associated with an increased risk of cancer, particularly gastrointestinal cancer. Although its use on cannabis plants is illegal, daminozide residues can still pose health risks when consumed.
3. Chlormequat chloride (CCC): CCC has been associated with reproductive and developmental effects in animal studies. It can potentially interfere with hormone function and fertility. Prolonged exposure to CCC can also cause respiratory and skin irritation. Inhaling or ingesting CCC residues on cannabis plants treated with this chemical can be harmful.
4. Ethephon: Ethephon can give off ethylene gas, which can have irritating effects on the respiratory tract. High levels of ethylene exposure can cause eye irritation, breathlessness and allergic reactions in some individuals. Although ethephon is generally considered safe for use on certain food crops, the safety of its use on cannabis plants has not been thoroughly investigated.
Again – it is important to note that these are all banned in the EU, Canada and the United States. Detection of the above harmful compounds is extremely rare in the samples we test.
Do you have to worry about PGRs?
Finally, the likelihood that your cannabis contains some level of PGRs is quite high, as in the fruits and vegetables you consume. But the levels are mostly low and safe. Dangerous PGRs are extremely rare and if your coffee shop tests their products, anything detected that contains above acceptable levels of any contamination will be removed from circulation and will not be sold to you.