This study was carried out to develop a high-performance liquid chromatography method for short-time analysis of the main cannabinoids in the inflorescence of hemp (Cannabis sativa L.). We also performed decarboxylation of the raw material using our advanced analysis technique. In this study, the UV spectrum was considered to analyze each of the four common cannabinoids, solvents, and samples, where the uniform elution of acidic cannabinoids without peak tailing and acids was tested. Optimal results were obtained when readings were taken at a wavelength of 220 nm using water and methanol containing trifluoroacetic acid as mobile phases in a solvent gradient system. The established conditions were further validated by system suitability, linearity, precision, detection limit, and quantitation limit tests. The decarboxylation index (DT50) confirmed that Δ9-THCA decarboxylated faster than CBDA, and both maintained a linear relationship with time and temperature. In addition, the loss of cannabidiol was better prevented during the decarboxylation process in the natural state than in the extracted state.

The performance of hemp seedlings was evaluated through morphological traits, photosynthetic pigments, and osmolytes under 11 light treatments (10 LED light compositions + natural light) in an aeroponics system. The seedlings were brought under treatment at 25 days of age, where the light intensity was 300 µmol m−2s−1 and duration was 20 days. A higher leaf number and node number were observed in L10 (R4:B2:W2:FR1:UV1) and L11 (R2:B2:G2:W2:FR1:UV1), and a higher leaf length and leaf width were recorded in the L2 (white), L3 (R8:B2), and L5 (R7:B2:FR1) treatments. Furthermore, a higher shoot length was recorded in L3 (R8:B2), L6 (R6:B2:G1:FR1), and L9 (R6:B2:FR1:UV1) while roots developed more in the L1 (natural light), L5 (R7:B2:FR1), and L9 (R6:B2:FR1:UV1) treatments. On the other hand, the L3 (R8:B2) treatment manifested higher chlorophyll a, chlorophyll b, and photosynthetic quantum yield (Fv/Fm). The hierarchical clustering and heatmap analysis revealed that higher leaf numbers and node numbers resulted in bushy plants with shorter shoots and longer roots. A negative correlation was also observed in photosynthetic traits (pigments and fluorescence) with osmolytes and root length. Importantly, the treatments L4 (R7:B2:G1), L6 (R6:B2:G1:FR1), L8 (R5:B2:G1:FR1:UV1), and L11 (R2:B2:G2:W2:FR1:UV1) manifested higher nodes with a higher osmolyte content, such as proline, ascorbic acid, total soluble carbohydrate, and sucrose, which may be a helpful indicator for higher branches and inflorescences, and ultimately higher cannabinoids accumulation in the plants. The approach and findings of this study could provide future research with the baseline information on optimizing the light composition to produce hemp plants with ideal phenotypes.

Production of plants under artificial light conditions is an innovative and smart concept to grow food year-round in any location. However, pre-basic seed potato production in the greenhouse from LED pre-treated seedlings under an aeroponic system is a new and creative idea. Therefore, the objective of the study was to optimize the effect of LED pre-treatment and determine the best LED spectral composition on growth performance and tuberization of potato plants. Potato variety ‘Golden King’ was treated under 9 LED light spectra for 30 days—L1 (natural light), L2, (R:B), L3 (R:B:G), L4 (R:B:FR), L5 (R:B:G:FR), L6 (R:B:G:FR:UV), L7 (R:B:FR:UV), L8 (R:B:W:FR), and L9 (R:B:W:FR:UV) under 300 µmol m−2 s−1 photosynthetic photon flux density (PPFD), 23/15 °C (day/night) temperature, and 70% relative humidity. The study revealed that growth characteristics and tuber number for plants were increased most by the light spectrum L4 (R:B:FR). Furthermore, photosynthetic pigments increased in L4, L7, and L8, while TSC and sucrose accumulated more in L1 treatment. In contrast, higher seed tuber fresh weight was recorded in L8, L9, L4, and L7. Overall, it can be concluded that potato seedlings pre-treated with the L4 (R:B:FR) LED spectral composition performed best for growth, establishment, and tuberization.

Manipulation of growth and development of cannabis (Cannabis sativa L.) has received considerable interest by the scientific community due to its high value in medicinal and recreational use worldwide. This study was conducted to investigate the effects of LED spectral changes on reactive oxygen species (ROS) and cannabinoid accumulation by provoking growth, pigmentation, photosynthesis, and secondary metabolites production of cannabis grown in an indoor environment. After three weeks of vegetative growth under greenhouse condition, plants were further grown for 90 days in a plant factory treated with 4 LED light compositions with a canopy-level photosynthetic photon flux density (PPFD) of 300 µmol m−2 s−1 for 16 h. Photosynthetic pigments and photosynthetic rate were linearly increased up to 60 days and then sharply decreased which was found most prominent in L3: MB 240 (Red 85% + Blue 15%) and L4: PF 240 (Red 70% + Blue 30%) LED light compositions. A high concentration of H2O2 was also observed in L3 and L4 treatments which provoked lipid peroxidation in later growth stage. In addition, higher accumulation of cannabinoid was observed under L4 treatment in most cases. It is also evident that higher ROS created a cellular stress in plant as indicated by higher osmolyte synthesis and enzyme activity which initiate quick maturation along with higher cannabinoids accumulation in cannabis plant. Therefore, it can be concluded that ROS metabolism has a crucial role in morpho-physiological acclimation and cannabinoid accumulation in hemp plants. The findings of this study provide further insight on the use of LED light to maximize the production of cannabinoid.

Cannabis breeders are combining several genes to develop economically valuable fiber, seed, and medicinal hemp. This study analyzed the characteristics and selection of traits based on cannabidiol production of medicinal cannabis lines successfully grown under artificial light and nutrient solution cultivation conditions in smart farm conditions. Sixteen female plants were selected by seeding medical hemp F1 hybrid specimens obtained by randomly crossing Cherry Wine and native hemp from each country. The F1 generation was treated with 12 h light to induce flower differentiation. CBD production peaked on day 50 of the treatment, and this was selected as the harvesting day. All F1 hybrids were separated by leaf and inflorescence after collecting morphological data, and fresh and dry weights were measured. The CBD production of leaf and inflorescence per cubic meter was calculated. The CW21-5 line produced a total of 53.002 ± 0.228 g of CBD per cubic meter, the highest CBD producer. In addition, heatmap correlation analysis showed that most morphological data were not related to cannabinoid content. Principal Component Analysis (PCA) and Self-Organizing Map (SOM) analysis showed that CW21-5 is an arbitrary line that does not cluster with other lines, and the reason for its excellent CBD yield per cubic meter is that it has a narrow plant diameter and a high CBD content at the same time.