Plant processes: Difference between revisions

Most plants are constantly respiring and cannabis is no exception. In the process of repirationrespiration, plants uptake CarbonCO₂ and expel Oxygen. CO₂ is essential to otherthe processesprocess such asof photosynthesis. If a plant is exposed to less than 200ppm it will be unable to photosynthesize at all and will most likely die. Airflow/ or "wind speed" has a strong effect on ratethe rates of respiration and transpiration.<ref>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)</ref> The rate of respiration is directly correlated with the stomata density on growing leaves.<ref>John W. Kimball, 2020. Gas Exchange in Plants. Available at: https://bio.libretexts.org/@go/page/5785 [Accessed March 11, 2022].</ref>

The cultivar constantly moves water around internally via capillary action and releases water vapourvapor into the environment through the stomata, this is the process of transpiration. The ratedensity of transpirationstomata canand behow approximatelyopen determinedthey byare will determine the rate of transpiration. The [[Temperature and Humidity#VPD|VPD]] of a plant's environment will affect its stomal response and in turn, its rate of transpiration. For higher VPD values rate of transpiration is generally higher up until a maximum threshold<ref>Plant responses to rising vapor pressure deficit, Grossiord 2020 - https://doi.org/10.1111/nph.16485</ref>. For Cannabis the maximum VPD is around 1.6kPa (Seedlings should be exposed to 0.4-0.8kPa until they are established). The rate of transpiration is also correlated to the light intensity the plant is being exposed to i.e. High light intensity equals a high rate of transpiration. TheOf course, the inverse correlation between humidity and rate of transpiration ishas usefulbeen toknown knowsince asthe it1930s.<ref>RELATIVE indicatesHUMIDITY theVARIATIONS rateAFFECTING ofTRANSPIRATION, nutrientHiram uptakeF. 97%Thut of1938 water-https://doi.org/10.1002/j.1537-2197.1938.tb09265.x</ref> CannabisWind absorbsspeed willand beCO₂ lostlevels viaalso transpiration,cause thisa isplant aresponse typicalthat characteristicwill ofaffect athe C3rate plantof transpiration.

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<ref>https://doi.org/10.1126%2Fscience.1115581 - Plant Circadian Clocks Increase Photosynthesis, Growth, Survival, and Competitive Advantage (2005)</ref><ref>https://doi.org/10.3389/fpls.2015.00245 - Interactions between circadian clocks and photosynthesis for the temporal and spatial coordination of metabolism (2015)</ref><ref>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</ref>

[http://www.plantcell.org/content/18/4/792 More on circadian rhythm in plants]<ref>https://doi.org/10.1105/tpc.106.040980 Plant Circadian Rhythms - C. Robertson McClung April 2006</ref>]