Saturday, August 1, 2020

When to Harvest Cannabis for Greatest Potency and Aroma

Cannabis terpenes are synthesized (manufactured) in the cytoplasm of the cells of the trichome head (TH) via the Mevalonic Acid pathway (MEV), and in plastids via the Methyl-Erythritol Phosphate pathway (MEP) . Monoterpenes, such as the pinenes (1), limonene, terpinolene and myrcene are a result of the MEV, while large terpenes like caryophyllene, farnesene and humulene are derived from the MEP. As the plant synthesizes more and more of the enzymes of terpene synthesis during flower, it makes perfect sense that their aroma becomes more prevalent and more precisely developed as the TH ripen.

Cannabinoids reach maximum concentration in the ninth week of flower (Aizpurua-Olaizola, et al, 2016). This is not a precise measurement, but rather a guide. Most growers believe harvest should take place whenever the TH become opaque and white, which is usually during the ninth week as molecules inside the TH pass their saturation point. Careful inspection and a watchful eye will notice the whiteness of TH without any need for magnification.


Simply keeping up with the number of flowering days elapsed will accurately hit this peak of cannabinoid concentration every time. There’s no need to break out the hand-held microscope and inspect flowers. Keep in mind that individual grow lights may be stronger or weaker than one’s flowers can tolerate, so results will vary. Nine weeks is sixty-three days.  Cannabis plants should generally be harvested on day 63 of the flowering phase, when cannabinoid concentration is at or near its maximum to begin preserving the flower in this optimum composition.

Some plants require a longer flowering period, sometimes up to thirteen weeks, to mature (e.g. Laughing Buddha). Once a plant’s maturation period is established for your conditions, that number of days can be relied upon. It is written in the plant’s genetics and there is no escape. 🌂

Reference
Aizpurua-Olaizola, O., Soydaner, U., Öztürk, E., Schibano, D., Simsir, Y., Navarro, P., ... & Usobiaga, A. (2016). Evolution of the cannabinoid and terpene content during the growth of Cannabis sativa plants from different chemotypes. Journal of natural products, 79(2), 324-331.

Notes:
1.    For the sake of brevity and to avoid confusion, terpenes are here named without prefixes such as "alpha" and "beta", as well as without chirality indications such the "d" prefix of d-Limonene.

8 FLOWERING STAGE TIPS FOR CANNABIS


Guest article by Leeanne Brooks

Growing cannabis is becoming a lucrative industry now that so many states and countries have lifted their ban on the plant. New farmers, however, will find it difficult to know when the flowering stage begins and when to harvest the plant. Below are a few tips on what to do during the flowering stage of cannabis.

Maintaining during flowering

Before the plants even get to their flowering stage, you should make sure that all plants are green, lush, and healthy. There shouldn't be any discolorations on the leaves because of a lack of nitrogen, nor should there be any signs of stress on the plants itself. If you notice any abnormalities, try to nurse the plant back to health before moving forward with the flowering stage.

If you've been giving the plant nutrients, make sure that you include a flowering formula during the first month of flowering. Try not to change the nutrient solution until you notice the plants develop plenty of pistils.

Using the right nutrients

During the flowering stage, the kind of nutrient that you give your plants will have to change. During this stage, it's important that the plants receive a lot of phosphorus and potassium to support the many changes they are undergoing. But keep in mind that before you change the fertilizers, ensure that plants are about to start flowering.

Use the flowering formula only in the first month of flowering. This stage will also require you to pay close attention to the plants to watch out for diseases and pest infestation which the plants are very prone to during this stage in their development.

Don't overfeed

It is during the last two weeks of the flowering stage where you should stop feeding plants nutrients. At this stage, the plants will start shedding some of their leaves. This happens because of the shift in the plant's allocation of energy from making food into developing buds. Signs that you're overfeeding are discoloration or leaves are being shed at a faster rate.

Train the plant

Training the plant means you help them maximize the use of the space in which they're growing to increase the yields. This applies especially if you are growing your cannabis indoors. Training is usually done during the first month of the flowering stage.

The cannabis plant has a flexible stem that is easy to manipulate once the plant enters its flowering stage. As they mature, the stems become more woody and difficult to train.

Supporting the plants

During the second month of flowering, the plant will start getting ready for harvest. They start to become thicker and develop more buds. The transparent resin on the leaves will start to darken and release a pungent odor. At this stage, the plants will require more support due to their weight. Set up a trellis system of strings and wires to give the plants more support.

Growing room conditions

If you're growing your cannabis indoors, it is during the flowering stage that you need to make sure that the conditions in the growing room are optimal. Since the plants are now growing closer together, you have to adjust the humidity and temperature to stop the plants from developing diseases and fungi.

Make sure that the temperature sits between 68 and 77 degrees Fahrenheit at the leaves and 68 degrees Fahrenheit at the roots. Once the plants are in their second month of flowering, you can drop the temperature several degrees so the buds produce more resin.

Monitor the pH levels

pH levels range from very acidic (0, 1, 2) to very basic (14)

If the pH levels of the soils are not right, your plants could suffer some damages leading to tainted products no reputable dispensaries will accept. Some common signs that the pH level is wrong is when you start seeing curly or wrinkly leaves on your plants. The perfect pH level of soil fit for growing cannabis is between 6.0 and 7.0. If however, you are using a hydroponic system, the pH level should be between 5.5 and 6.5.

Knowing when to harvest

The flowering stage of cannabis plants will vary depending on the strain you are growing but will typically last around two months. The moment the calyces and pistils start to swell and turn red, the plant is ready for harvest.

The plant will continue to accumulate resin and flowering tops will become stickier and heavier. Because of this, the flowers may need support and may appear to move closer together. At this stage, you must have your carbon filters up since the smell emanating from the buds may attract unwanted attention from the neighbors. 🌂

Leanne Brooks is a passionate blogger who loves to write about innovative ideas on promoting mental and physical health for companies like GreenSociety, a licensed Medical Marijuana dispensary delivering premium quality cannabis to Canadian MMJ patients with online ordering.

Thank you, Canadian MMJ patients. Your purchase from GreenSociety supports Seattle Bliss via this affiliate link: Click to visit the GreenSociety website

Questions and Comments regarding this Seattle Bliss article are welcome below, or by emailing editor@hg420mag.com

Reference Links

https://hightimes.com/grow/common-weed-mutations/
https://wayofleaf.com/cannabis/growing/best-fertilizers-for-growing-cannabis
https://www.leafly.com/news/growing/flush-cannabis-plants
https://www.cannabisbusinesstimes.com/article/the-perfect-grow-environment/

Tuesday, July 21, 2020

Cannabis Potency Not Strictly a Function of Trichome Density


Trichomes are tiny globular or hairlike structures that grow on the surface of Cannabis plants. The "heads" may be either stalked or sessile (without a stalk), and they produce and store cannabinoids in these globular heads (Dayanandan & Kaufman, 1976; De Pasquale, 1974; Fairbairn, 1972).

Cannabinoids are the major molecules produced and stored in the trichome head (TH), such as CBG, THC and CBD (Flores-Sanchez, et al, 2008). Generally, THC is psychotropic, but the others are not. Terpenes are also produced and stored in these globular structures. Development of stalked, globular trichomes, where the majority of cannabinoids are found, is shown in the image below.


While enormous flowers can be fun, normal sized flowers may be the most potent. Considering two identical clones, one flowered under lights, and the other in full sun, both genetically grow flowers with a similar number of trichomes. However, because the outdoor plant’s energy source is so rich, bract size is much larger than that of the indoor plant. Dayanandan and Kaufman (1976) demonstrated this with a rich collection of images (References, below).


Any cannabis flower may appear ordinary to the naked eye, but take a closer look and you’ll see a crystalline forest of clear to white and amber trichomes. Trichomes should cover the entire surface of every part of the flower remaining from trimming. The closer to full coverage, the gentler the handling must have been. Less than full coverage means less than 100% of the plant’s trichomes (and cannabinoids) remain.

According to Turner, et al (1981), it is actually the number of trichomes that cover the cannabis bract and not trichome density that affects cannabinoid potency. This is to illustrate how identical plants grown side-by-side will have identical number of trichomes at all stages, but will exhibit differing trichome densities at different time points as bracts become engorged and ripen. Their study demonstrated that cannabinoid composition changed during the final weeks of flowering, but total trichomes and total cannabinoids remained the same.

The changes happening as flowers ripen include CBG enzymatically becoming THC or CBD, then either of those is oxidized by age, heat and light to form CBN. The progression is evident as total cannabinoids reach saturation in the TH and cause them to appear opaque white. This saturation is a signal for the grower to harvest. TH may become amber in color as some of the THC oxidizes to become CBN.

Most growers strive for THC potency above 20% because that’s what consumers demand. The greater the THC potency, the greater the wholesale price. Retailers buy and price their products according to the laboratory’s test report AND their own observations. Today’s cannabis retails from $3/gram bargain ounces to $15/gram and up for the truly rare or exceptional crops.
In each set of images below Trichome Density varies from one flower to the next, but the main difference among clean growers is handling.

Peaches and Diesel (Indoor; Hydro)



Amherst Sour Diesel (Indoor; Hydro)




The Look (Indoor; Soil)




Tangie (Outdoor; Soil)




Now observe (click to enlarge the images above) how Trichome Density is greater with each specimen because of handling. Notice that some images have a high number of trichome heads missing, perhaps because they were knocked off by rough handling of drying flowers. Other images feature a product that is not over-dried or over-ripe, and handled with gentle care.

And now see the difference in the condition of these trichomes. The grower clearly invests greater care into their product as you can see their trichome heads are intact, large, full, and less than one-third amber in color.

Strawberry Diesel (Outdoor; Soil)




Girl Scout Cookies (Indoor; Soil)






In summary, a cannabis flower swollen to ten percent greater mass by one additional week of cultivation, but with the same total number of healthy, capitate trichomes (those with heads intact), should exhibit less potency (mg THC per gram of cannabis flower). Outdoor flowers may grow larger than identical indoor clones, but are slightly less potent due to genetic limits placing a set number of trichomes on the surface of a bract.

Why do some prefer Outdoor cannabis? Some say flavor; others say a mellow experience is just what the doctor ordered. Exploration is up to you.

Explore your preferences by keeping a personal cannabis journal at HigherGround420.com. Tools and analyses of what YOU LIKE help you discover other sources and other strains you may like. Subscribe FREE by using GROUP_ID "Seattle Bliss".


References

Dayanandan, P., & Kaufman, P. B. (1976). Trichomes of Cannabis sativa L.(Cannabaceae). American Journal of Botany, 63(5), 578-591. https://deepblue.lib.umich.edu/bitstream/handle/2027.42/142132/ajb211846.pdf

De Pasquale, A., Tumino, G., & De Pasquale, R. C. (1974). Micromorphology of the epidermic surfaces of female plants of Cannabis sativa L. Bull. Narc, 26(4), 27-40. http://www.unodc.org/unodc/en/data-and-analysis/bulletin/bulletin_1974-01-01_4_page005.html

Fairbairn, J. W. (1972). The trichomes and glands of Cannabis sativa L. Bull. Narc, 23, 29-33. https://www.unodc.org/unodc/en/data-and-analysis/bulletin/bulletin_1972-01-01_4_page005.html

Turner, J. C., Hemphill, J. K., & Mahlberg, P. G. (1981). Interrelationships of glandular trichomes and cannabinoid content. I. Developing pistillate bracts of Cannabis sativa L.(Cannabaceae). Bull Narc, 33(2), 59-69. https://www.unodc.org/unodc/en/data-and-analysis/bulletin/bulletin_1981-01-01_2_page008.html

Flores-Sanchez, I. J., & Verpoorte, R. (2008). Secondary metabolism in cannabis. Phytochemistry reviews, 7(3), 615-639. https://www.academia.edu/download/50204643/s11101-008-9094-420161109-6396-2tzphv.pdf