Plant processes

There are many biological processes that occur, mostly simultaneously, in a living plant. Some processes continue even after the cultivar is harvested like in the case of the curing process.

Photosynthesis

The Cannabis plant photosynthesizes in the presence of light like most plants, it is categorized as a C3 plant.

C3 carbon fixation in photosynthesis leads to several characteristics:

Thrives where CO₂ concentration is > 200ppm (cannabis specifically thrives in >400ppm CO₂)
Cannot survive in very hot environments

Cannabis stands out from other plants for its tolerance to high light intensity. see Ideal light conditions

Respiration

Most plants are constantly respiring and cannabis is no exception. In the process of repiration plants uptake Carbon and expel Oxygen. CO₂ is essential to other processes such as photosynthesis. Airflow/wind speed has a strong effect on rate of respiration and transpiration.^[1] The rate of respiration is directly correlated with the stomata density on growing leaves.^[2]

Supplimenting additional CO₂

In a city typical Co₂ levels are around 400-450ppm. This is acceptable for a growing plant but raising levels above 1000ppm can increase growth rates by up to 30%.

Transpiration

The cultivar constantly moves water around internally and releases water vapour into the environment through the stomata, this is the process of transpiration. The rate of transpiration can be approximately determined by the VPD of a plant's environment. The rate of transpiration is also correlated to the light intensity the plant is being exposed to i.e. High light intensity equals high rate of transpiration. The rate of transpiration is useful to know as it indicates the rate of nutrient uptake. 97% of water Cannabis absorbs will be lost via transpiration, this is a typical characteristic of a C3 plant.

Circadian rhythm

Like animals, plants also have a Circadian rhythm, a sort of internal biological clock that is programmed by external stimuli. It has been shown that matching a plant's environment to its natural circadian rhythm can increase photosynthesis^[3]^[4]^[5]

References

↑ https://doi.org/10.1016/S0273-1177(02)00747-0 - Effects of air current speed on gas exchange in plant leaves and plant canopies (2003)
↑ John W. Kimball, 2020. Gas Exchange in Plants. Available at: https://bio.libretexts.org/@go/page/5785 [Accessed March 11, 2022].
↑ https://doi.org/10.1126%2Fscience.1115581 - Plant Circadian Clocks Increase Photosynthesis, Growth, Survival, and Competitive Advantage (2005)
↑ https://doi.org/10.3389/fpls.2015.00245 - Interactions between circadian clocks and photosynthesis for the temporal and spatial coordination of metabolism (2015)
↑ https://doi.org/10.1016/j.scienta.2014.03.014 - Leaf photosynthesis, plant growth, and carbohydrate accumulation of tomato under different photoperiods and diurnal temperature differences

[1] ttps://doi.org/10.1016/S0273-1177(02)00747-0 - Effects of air current speed on gas exchange in plant leaves and plant canopies (2003)

[2] John W. Kimball, 2020. Gas Exchange in Plants. Available at: https://bio.libretexts.org/@go/page/5785 [Accessed March 11, 2022].

[3] ttps://doi.org/10.1126%2Fscience.1115581 - Plant Circadian Clocks Increase Photosynthesis, Growth, Survival, and Competitive Advantage (2005)

[4] ttps://doi.org/10.3389/fpls.2015.00245 - Interactions between circadian clocks and photosynthesis for the temporal and spatial coordination of metabolism (2015)

[5] ttps://doi.org/10.1016/j.scienta.2014.03.014 - Leaf photosynthesis, plant growth, and carbohydrate accumulation of tomato under different photoperiods and diurnal temperature differences

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