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Environmental factors throughout the growing process impact cannabis yield and quality.
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Cannabis has attracted a new wave of research attention as an herbal medicine. To deliver compliant, uniform, and safe cannabis medicine, growers should optimize growing environments on a site-specific basis. Considering that environmental factors are interconnected, changes in a factor prompts adjustment of other factors. This paper reviews existi...
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... Of other important factors that contribute to the overall inflorescence yield, such as growing medium 12,16 , plant architecture 17 , plant density 8,18 , temperature 19 , water supply 20,21 , light spectrum and intensity [22][23][24][25][26] , mineral or organic fertigation 27 , arguably plant genetics is the most influential 14,28,29 . Genetic heritability largely determines plant morphology and its chemical profile in cannabis 30 . ...
Nitrogen (N) nutrition and germplasm of clones can influence biomass and cannabinoid concentration in medicinal cannabis. However, there are discrepancies on the optimal nitrogen (N) application rate at the flowering stage to achieve maximum yield and if, or how, this interacts with clones from different seed lines of the same genotype. This research examined the relationship between N application rate, concentration of cannabinoids and biomass yield of a CBD-type medicinal cannabis cultivar in clones propagated from five different seed lines (hereafter referred to as clones). Clonal rooted cuttings were propagated from five mother plants germinated from seeds of cultivar ‘Tas1’. Five N levels (30, 90, 160, 240 and 400 mg/L N) were imposed at the start of the inflorescence period and continued until harvest eight weeks later. Some pollen contamination occurred during the trial so that seed biomass was assessed for each plant and included in statistical analysis. Weight of total biomass, leaves and inflorescence (from upper and lower canopy positions), N%, and cannabinoid concentrations were measured after the harvest. Results indicated that increasing N supply generated a clear upward trend in inflorescence biomass that peaked at 160 mg/L N after which it did not significantly change, while leaf biomass steadily increased with N. Delta9-tetrahydrocannabinol (THC) and cannabidiol (CBD) concentrations decreased significantly with increasing N concentration in leaves with a similar, but non-significant, trend for inflorescences. The CBD to THC ratio increased with increased N. Clone source was strongly correlated with cannabinoid concentration, but not leaf, inflorescence or total biomass, across all N treatments. Clones 13 and 27 developed greater cannabinoid concentrations relative to clones 18 and 26 irrespective of N treatment. Pollen contamination induced seed development that comprised up to 5% of inflorescence biomass dry weight but this did not significantly affect whole-plant biomass, N accumulation (N%), or cannabinoid concentration. These findings provide valuable insights for improving cannabinoid yield in this widely cultivated plant species.
... General procedures for propagation and the vegetative period. Seventy-two shoot-tip cuttings (length, 6 cm) were harvested from chemotype III 'Southern OG' (The Hemp Mine, Fairplay, SC, USA) stock plants maintained under a 21-h photoperiod; chemotype III is defined as CBD-dominant with a THC concentration <0.3% (Jin et al. 2019). All leaves with petioles >2 cm in length were removed, and the basal 2 cm of each cutting's stem was dipped in a rooting solution consisting of 3000 mg·L À1 naphthyl acetic acid. ...
... Cannabinoid concentrations peaked and then declined before reproductive mass growth ceased, which means that these parameters must be considered together to maximize yield. The diversity among cannabis cultivars corresponds to large variations in morphological and physiological development that affect biomass growth, secondary metabolism, and, ultimately, yield (Jin et al. 2019). Cultivar evaluations are necessary to guide production scheduling if growers seek to maximize yield and profitability. ...
Harvest timing is a crucial production decision that affects the yield and quality of horticultural crops, yet little research-based information is available to guide this decision for cannabis ( Cannabis sativa L.) production. The objective of this study was to quantify temporal changes in dry mass and tissue cannabinoids under an inductive photoperiod to track yield and identify optimal harvest timing. This information can be used to guide production scheduling. Two experiments were conducted that flowered cannabis ‘Southern OG’ under a 12-h photoperiod for 8 weeks (Expt. 1) or 10 weeks (Expt. 2) with weekly destructive harvest of whole plants beginning on the fourth week. Two distinct trends were revealed as flowering progressed: reproductive dry mass increased linearly each week and the cannabinoid concentration increased to a maximum and then gradually declined. On a per-crop basis, harvesting at 9 or 10 weeks resulted in maximum cannabidiol (CBD) yield or tetrahydrocannabinol (THC) yield, respectively. On an annual basis, reproductive dry yield was greatest when harvesting at 10 weeks, while cannabinoid yield declined when harvesting after 8 weeks. These results demonstrate that optimal harvest timing depends on the final product of interest (e.g., dried inflorescences or tissue extracts) because the maximum yield of reproductive mass and cannabinoids occurred in different harvest timing treatments. Commercial growers must also consider production costs and product value. Longer crop cycles are desirable to reduce variable costs, such as containers, substrate, and cuttings, but the accompanying decline in cannabinoid concentration with longer crop cycles adversely impacts the perceived quality and economic value of dried inflorescences. Therefore, optimal harvest timing depends on the interactions of yield, production cost, and product value.
... A recent study by Caplan et al. (2019) showed that THC levels increased by 50% when cannabis was drought-treated for 11 days during flowering. Harvesting at the right time is also important; farmers should avoid harvesting too late because longer flowering times tend to increase THC levels (Jin et al., 2019;Yang et al., 2020). ...
Industrial hemp (Cannabis sativa L.) exhibits growth potential in water‐limited regions due to its deep roots and drought tolerance. However, limited knowledge exists about its agronomic production in semiarid West Texas. A 2‐year (2022–2023) field experiment evaluated the effect of planting dates (P1: April 19, P2: May 10, and P3: June 6) and seeding densities (SD1: 84500 seeds ha⁻¹, SD2: 1,408,000 seeds ha⁻¹, and SD3: 1,972,000 seeds ha⁻¹) on the growth, physiology, and yield of hemp in a split‐plot block design. In both years, P3 reduced photosynthesis but increased transpiration compared to earlier plantings. In 2022, SD1 increased transpiration during the vegetative stage; however, no significant difference was observed during 2023. Photosynthesis remained consistent among densities throughout both years. In 2022, P2 accumulated 15%, 24%, 33%, and 43% greater plant height, biomass, bast fiber, and hurd fiber, respectively, but 45% lower grain yield than P3. In 2023, P1 and P2, on average, produced 32%, 175%, 149%, and 243% greater height, biomass, bast fiber, and hurd fiber than P3, respectively, while P2 accumulated 36% higher grain yield than P1 and 94% than P3. In 2022, SD3 had the highest bast, while hurd yield did not differ among densities. During 2023, SD3 produced the greatest bast and hurd fiber and significantly greater grain yield than SD1, with no variation with SD2. In conclusion, these findings suggest that early planting at higher seeding density can maximize resource use efficiency and production in West Texas. This makes them a viable strategy for sustainable hemp production under water‐limited conditions.
... Curing is another important subsequent postharvest process of drying that significantly affects the quality of plant tissues, particularly the smokable inflorescence and leaves of tobacco [12]. Curing is sometimes called the 'maturation' or 'aging' process, which, in practice, is performed by storing the dried hemp in closed containers under specific temperature and humidity conditions for a certain period of time to allow for the change in flavor profiles [13]. This relatively long process under mild temperature and humidity allows moisture in the dried hemp to re-equilibrate to the controlled environmental conditions to mitigate any over-drying issues. ...
... If not properly cured, these chemical compounds will result in rough, harshhitting smoke and a raw plant taste during burning. Jin et al. [13] suggested that curing at 18 • C and 60% RH for 2 weeks with the lid open after 6 h, rendered the best flower quality. Lazarjani et al. [14] stated that the curing process resulted in decarboxylation and an increase in THC and CBN in medicinal hemp flowers and increased potency. ...
Postharvest operations affect the yield and quality of industrial hemp (Cannabis sativa L.). This study aimed to investigate the postharvest drying and curing effects on the key quality and safety indicators of cannabinoid-type hemp. Freshly harvested hemp inflorescence of Hempress and Wild Bourbon cultivars were dried by three methods: (1) Hot air drying at 75 °C; (2) Ambient air drying at 25 °C; and (3) Freeze drying. The dried hemp was then cured in sealed glass jars or mylar bags in dark conditions at ambient temperatures. The drying time, overall cannabinoid contents, decarboxylation level, color metrics and total aerobic loads were experimentally determined. Hot air drying can reduce the hemp moisture from 77% to safe-storage level of 6% within 8 h, and achieved up to 2-log reduction in the total yeast and mold counts. The drying time required for ambient air drying and freeze drying were 1 week and 24 h, respectively. Curing led to a 3.3% to 13.6% increase in hemp moisture, while the influence of curing method was not significant. Both drying and curing did not significantly affect the total cannabinoid contents, but resulted in decarboxylation, and reduction in the greenness. The findings suggested that hot air drying followed by glass jar curing is preferred for higher drying efficiency, better preservation of the cannabinoids and microbial safety.
... According to the literature survey by Lazarjani et al., (2021) [38], external factors such as light duration, oxygen, and harvest time (floral maturity) have been shown to influence the secondary metabolite production in cannabis [37][38][39][40][41][42][43]. Three conditions were used to store cannabis resin (hashish slabs) and extract (by the solvent): room temperature and 4°C both with visible light exposure and darkness, and − 20°C in darkness [37,[38][39][40][41][42][43]. ...
... According to the literature survey by Lazarjani et al., (2021) [38], external factors such as light duration, oxygen, and harvest time (floral maturity) have been shown to influence the secondary metabolite production in cannabis [37][38][39][40][41][42][43]. Three conditions were used to store cannabis resin (hashish slabs) and extract (by the solvent): room temperature and 4°C both with visible light exposure and darkness, and − 20°C in darkness [37,[38][39][40][41][42][43]. One of the study identified that in cannabis resin, light exposure can affect the decarboxylation of THCA and the degradation of THC [37,[38][39][40][41][42][43]. ...
... Three conditions were used to store cannabis resin (hashish slabs) and extract (by the solvent): room temperature and 4°C both with visible light exposure and darkness, and − 20°C in darkness [37,[38][39][40][41][42][43]. One of the study identified that in cannabis resin, light exposure can affect the decarboxylation of THCA and the degradation of THC [37,[38][39][40][41][42][43]. This is evident as the half-life increased by 40% in darkness [37,38]. ...
This review paper highlights and updates the recent robust extraction methods for phytocannabinoids, hydrodynamic extraction technology and use of vegetable oil as the solvent system. Hydrodynamic cannabis extraction is a recent development within the cannabis industry that can be used to produce full-spectrum cannabis extracts with high bioavailability. According to the patented hydrodynamic extraction technology by Clean Green Biosystems, Chennai, Tamilnadu, India, the system is the first of its kind to be able to use whole, freshly harvested cannabis materials. Clean Green Biosystems, Chennai, Tamilnadu, India reports that Hydyne is innovative new hydrodynamic extraction system that uses the entire fresh plant materials to preserve all the unique phytochemicals and phytonutrients compounds in a full spectrum/broad spectrum extract. Hydrodynamic system converts the cannabis plant material into a cannabis nano-emulsion by means of hydrodynamic force and ultrasonification by breaking the cell walls of the plant material and releases them into the aqueous phase. PhytoX TM (USA) is another new hydrodynamic extraction system developed by IASO Inc (Incline Village, Nevada, USA) that can process whole, fresh, un-dried cannabis plants, which maximizes plant utilization, reduces processing costs, and increases yields. Many traditional extraction methods can not guarantee the integrity of unstable compounds. Hydrodynamic extraction is designed to use fresh and whole plants, ensuring these volatile molecules are kept intact. Additionally, the distillation prevents the phytocannabinoids from thermal degradation, further protecting molecule integrity. The aroma of the resultant cannabis products is stronger than traditional extracts. Because the plant material is frozen in the preparation stage of the system, it allows the aromatic compounds to remain intact.
... For instance, high temperatures can accelerate maturity by inducing flowering and result in stunted growth [26]. Temperature also affects net photosynthesis (PN): low temperatures slow PN, while excessive heat stops it, forcing plants to use up energy on cooling through water uptake and transpiration [70]. ...
This study investigated the effect of temperature on the germination and seedling biochemical profiles of eight cannabis landraces, namely Ladysmith Ugwayi wesiZulu (L1) and Iswazi (L2), Durban Poison (H1), Bergville Ugwayi wesiZulu (B1), Natal (B2), and Iswazi (B3), and Msinga Ugwayi wesiZulu (M1) and Iswazi (M2). Seed viability, germination rate, and germination percentage were evaluated along with seedling amino acids, carbohydrates, and fatty acids methyl esters (FAMEs) under day/night temperature regimes of 20/15 °C, 30/25 °C, and 40/35 °C. Results showed a significant effect (p < 0.001) of temperature on germination percentage, rate, and biochemical profiles of cannabis landraces. Landraces L1, B1, H1, B2, and M1 had higher germination at 20/15 °C, while B3, M2, and L2 performed better at 30/25 °C. Biochemical profiles varied with temperature and landraces. Amino acid content increased with temperature but did not correlate with germination indexes. Carbohydrates and FAMEs decreased with rising temperature, peaking at 30/25 °C. FAMEs strongly correlated with germination indexes, linking lipid composition to seed performance. Sorbitol positively correlated with germination, while glucose and fructose showed indirect correlations. This study underscores the impact of temperature on germination and the biochemical profiles of cannabis landraces, highlighting the importance of considering genotype-specific responses in varietal selection.
... As with other plants, substantial variation in growth conditions used for the growth of hemp-or drug-type Cannabis with respect to light, temperature, day length, or cultivation spaces (field, glasshouse, controlled environments) are expected to determine genotype-specific nutrient requirements, their optimization, and impact on yield (Backer et al., 2019;Jin et al., 2019). For the production of highly regulated phytoceuticals such as cannabinoids, protected cropping systems are ideally suited as they allow for controlled nutrient supply avoiding heavy metals or sodium accumulation, while also allowing integrated pest management and thus avoiding the introduction of unwanted chemical residue or toxins (Stone, 2014). ...
Cannabis sativa L., one of humanity’s oldest cultivated crops, has a complex domestication history due to its diverse uses for fibre, seed, oil and drugs, and its wide geographic distribution. This review explores how human selection has shaped the biology of hemp and drug-type Cannabis, focusing on acquisition and utilisation of nitrogen and phosphorus, and how resulting changes in source-sink relations shape their contrasting phenology. Hemp has been optimized for rapid, slender growth and nutrient efficiency, whereas drug-type cultivars have been selected for compact growth with large phytocannabinoid producing female inflorescences. Understanding these nutrient use and ontogenetic differences will enhance our general understanding of resource allocation in plants. Knowledge gained in comparison with other model species, such as tomato, rice or Arabidopsis thaliana can help inform crop improvement and sustainability in the Cannabis industry.
... Zdarza się jednak, że proces ten może także prowadzić do rozkładu lub parowania bardziej lotnych substancji, na przykład terpenów [37]. Przyczyną tego mogą być nieprawidłowe warunki suszenia, mogące powodować dekarboksylację form kwasowych kanabinoidów i utratę terpenów [38]. Oleje roślinne, takie jak olej rzepakowy, słonecznikowy czy oliwa z oliwek, jako substancje lipofilowe, umożliwiają selektywnie ekstrahowanie surowca. ...
Przedmiot badań: Konopie indyjskie były stosowane w medycynie od wieków. Historycznie rzecz biorąc, leki na bazie konopi były stosowane w leczeniu wielu schorzeń. W XX wieku nastąpiła penalizacja ich stosowania na świecie. Współcześnie wiele krajów dekryminalizuje ich stosowanie. Złożoność tematyki, zmienność jakościowa składników aktywnych poszczególnych odmian tego gatunku determinuje nowe obszary wymagające badania i analizy. Na uwagę zasługują kwestie prawne, problematyka kontroli jakości, niedobory randomizowanych i kontrolowanych badań klinicznych. Artykuł skierowany jest zarówno dla profesjonalistów związanych z opieką zdrowotną, jak i dla osób zainteresowanych zagadnieniami prawno-medycznymi oraz potencjalnymi korzyściami i wyzwaniami związanymi z konopiami medycznymi. Cel badań: W pracy przeanalizowano aspekty prawne i praktyczne dostępu do marihuany i jej stosowania do celów medycznych w Polsce. Materiał i metody: Analizy zagadnienia dokonano na podstawie aktualnego przeglądu piśmiennictwa. Porównanie rozwiązań i przeanalizowanie różnic w regulacjach prawnych marihuany stosowanej do celów medycznych w wybranych krajach umożliwi również wskazanie kierunków rozwoju w tym obszarze w Polsce. Wyniki: W niniejszej pracy omówiono ramy prawne dostępu do konopi medycznych i ich zastosowania do celów medycznych. W obrocie w Polsce znajduje się aktualnie co najmniej dwadzieścia jeden rodzajów surowców, które nawet przy zachowaniu tych samych poziomów THC (tetrahydrokannabinol) i CBD (kannabidiol), różnią się profilem terpenowym i tym samym szczegółowymi właściwościami terapeutycznymi, których znajomość może umożliwić farmaceutom wspieranie i monitorowanie farmakoterapii pacjentów w tym obszarze. Przestrzeń medycznego zastosowania konopi omówiona została także w aspekcie możliwości współpracy lekarzy i farmaceutów w ramach sprawowania usług na rzecz pacjenta celem osiągnięcia skuteczności terapeutycznej i wypracowania narzędzi zarządzania ryzykiem farmakoterapii konopiami medycznymi. Wnioski: W miarę łagodzenia ograniczeń w badaniach i stosowaniu, z pewnością zostaną znalezione nowe możliwości terapeutyczne. Tym samym pomimo licznych wyzwań związanych z zastosowaniem Cannabis jak problemy doboru surowca, kontroli jakości, stabilności, bezpieczeństwa i skuteczności, należy uznać za pozytywne dotychczasowe osiągnięcia, również o istotnym znaczeniu dla systemu opieki zdrowotnej w Polsce.
... Temperature control is a critical environmental factor that plays a pivotal role in plant growth and development, including that of medical hemp [20,21]. The optimal temperature for hemp cultivation is approximately 24 • C [22], with temperatures above 30 • C or below 20 • C resulting in decreased photosynthesis and nighttime respiration rates [19]. In terms of cannabinoid contents, tetrahydrocannabinol (THC) levels have been reported to increase under low temperatures of approximately 23 • C compared to high temperatures of approximately 32 • C [23]. ...
This study was conducted to determine the optimal temperature difference in day–night indoor cultivation conditions to enhance the flower yield and functional component contents of female hemp plants. Hemp clones were cultivated under five distinct day and night temperature differences (DIF) during the reproductive stage. The daytime and nighttime temperature settings were as follows: 18:30 °C (negative 12 DIF), 21:27 °C (negative 6 DIF), 24:24 °C (0 DIF), 27:21 °C (positive 6 DIF), and 30:18 °C (positive 12 DIF). Seven weeks after transplantation, the growth parameters, leaf gas exchange, total phenolic compounds, 2,2-diphenylpicrylhydrazyl scavenging activity, and cannabinoid contents were analyzed. The total shoot biomass based on dry weight was highest at 21:27, reaching 41.76 g, and lowest at 30:18, measuring 24.46 g. However, the flower biomass, which is the primary production site, was highest at 24:24 and lowest at 18:30, showing a 4.7-fold difference. The photosynthesis-related parameters were temperature-dependent and strongly correlated with biomass production. The cannabinoid content of the hemp leaves increased at 21:27, whereas that of the hemp flowers increased at 27:21. The findings of this study indicate that the optimal temperature condition for female hemp flower production in a limited space is positive 6 DIF treatment, which corresponds to 27:21 °C. These results can contribute to advancements in indoor crop cultivation technology.
... Indoor medicinal cannabis cultivation systems enable year-round cultivation, especially in temperate regions. Such systems offer more control of the overall production, with a higher degree of specialization, modification of the environmental conditions (i.e., light, air circulation, humidity and temperature) and plant abiotic stress induction (Cervantes, 2006;Jin et al., 2019;Malıḱ et al., 2021). However, indoor systems are energy-and resource-intensive (Madhusoodanan, 2019;Wartenberg et al., 2021) while negatively affecting the environment through water, air and land pollution due to high water and fertilizer consumption (Pagnani et al., 2018;Zheng et al., 2021). ...
Indoor medicinal cannabis cultivation systems enable year-round cultivation and better control of growing factors, however, such systems are energy and resource intensive. Nutrient deprivation during flowering can trigger nutrient translocation and modulate the production of cannabinoids, which might increase agronomic nutrient use efficiency, and thus, a more sustainable use of fertilizers. This experiment compares two fertilizer types (mineral and organic) applied in three dilutions (80, 160 and 240 mg N L⁻¹) to evaluate the effect of nutrient deprivation during flowering on biomass, Cannabidiol (CBD) yield and nutrient use efficiency of N, P and K. This is the first study showing the potential to reduce fertilizer input while maintaining CBD yield of medicinal cannabis. Under nutrient stress, inflorescence yield was significantly lower at the final harvest, however, this was compensated by a higher CBD concentration, resulting in 95% of CBD yield using one-third less fertilizer. The higher nutrient use efficiency of N, P, and K in nutrient-deprived plants was achieved by a larger mobilization and translocation of nutrients increasing the utilization efficiency of acquired nutrients. The agronomic nutrient use efficiency of CBD yield – for N and K – increased 34% for the organic fertilizers and 72% for the mineral fertilizers comparing the dilution with one-third less nutrients (160) with the highest nutrient concentration (240). Differences in CBD yield between fertilizer types occurred only at the final harvest indicating limitations in nutrient uptake due to nutrient forms in the organic fertilizer. Our results showed a lower acquisition and utilization efficiency for the organic fertilizer, proposing the necessity to improve either the timing of bio-availability of organic fertilizers or the use of soil amendments.
