## 3 Results and Discussion  
### Selection according to Cannabidiol Content  
The terminal stems of the mother plant and 16 specimens of F1 generation hemp that had adapted to the transition from growing in soil to LED smart farming are shown in Figure 3.  
The cannabinoid content depends on the time of harvest, the environment [42], and the characteristics of the variety [43]. Therefore, it is essential to analyze the content. Analysis of CBDA + CBD during the flowering treatment showed a similar cannabinoid pattern in all plants. The CBDA + CBD content of the leaves was 0.7586 \(\pm\) 0.3549% on day 21, the lowest at 0.6061 \(\pm\) 0.2747% on day 35 day, 0.3659 \(\pm\) 0.1962% on day 44, and the highest at 1.7316 \(\pm\) 0.7442% on day 50 (Figure 4A). The CBDA + CBD content of inflorescences increased to 2.6513 \(\pm\) 0.6371% on day 21 and 5.0402 \(\pm\) 1.6898% on day 35, then decreased to 2.2593 \(\pm\) 0.9702% on day 44 and peaked at 5.4966 \(\pm\) 1.5041% on day 50. Ref. [43] also reported that the highest CBD content was found 6-7 weeks after flowering, which is consistent with our results (Figure 4B). \begin{table}
\begin{tabular}{c c} \hline \hline
**Equipment** & **Condition** \\ \hline Instrument & Shimadzu LC-20 AT HPLC system \\ Column & Reverse phase Zorbax SB-C18 (4.6 mm \(\times\) 100 mm, 3.5 \(\upmu\)m) \\ Detector & UV-Vis detector (220 nm) \\ Elution type & Gradient \\ Mobile phase & Solvent A: Water containing 0.05\% TFA \\  & Solvent B: Acetonitrile containing 0.05\% TFA \\ Flow rate & 1.5 mL/min \\ Oven & 27 \({}^{\circ}\)C \\ Injection volume & 10 \(\upmu\)L \\ \hline \hline \end{tabular}
\end{table} 
Table 2: HPLC conditions. \(\Delta\)9-THCA + \(\Delta\)9-THC content in the leaves had a slightly different pattern from the CBDA + CBD content. The leaf content was 0.1221 \(\pm\) 0.0325% on day 21, 0.0956 \(\pm\) 0.0306% on day 35, 0.0594 \(\pm\) 0.0270% on day 44, and 0.0471 \(\pm\) 0.0232% on day 50 (Figure 4C). The \(\Delta\)9-THC(A) content of inflorescence was 0.0607 \(\pm\) 0.0133% on day 21, increased to 0.1747 \(\pm\) 0.0607% on day 35, decreased to 0.0583 \(\pm\) 0.0185 on day 44, and increased to 0.2214 \(\pm\) 0.0579% on day 50, which was similar to the CBD(A) trend of the inflorescence (Figure 4D). The lowest \(\Delta\)9-THC content and the highest CBD content in the leaf  
Figure 3: Branch tip shape of hemp mother plant and F1 hybrids. The samples were collected on day 50 of the flowering treatment (short light length, 12 h light/day). (**A**) Mother plant; (**B**) CW21-5 line; (**C–Q**) F1 generation except CW21-5 line. were observed on day 50, and the plant harvest time was set on day 50 of the short-day length treatment. Table 3 shows the morphological data collected prior to harvesting. The mother plant was fixed as 'Cherry wine' variety, but had various traits, including cannabinoid content. All petioles and the stems of most plants of the F1 line were red. The morphological data were important for further evaluation of CBD production per unit and correlation with cannabinoids. Figure 4: Cannabinoid content by strain and date. (**A**) CBD + CBDA of leaf, (**B**) CBD + CBDA of infloresence, (**C**) \(\Delta\)9-THC + 9-THCA of leaf, (**D**) \(\Delta\)9-THC + \(\Delta\)9-THCA of infloresence. Indications of 21 st-50 th represent the days of short daylight treatment. The number of branches showed a higher number (16.25) than the 'NB100' variety (7.67) investigated in the previous study [44]. However, considering that the number of branches varies depending on the cultivation environment or the number of days of vegetative growth, comparison with the mother plant is preferable to comparison with other plants [45]. Lines CW21-3, 4, 5, 6, and 7 showed a higher number of branches than the mother plant grown under the same conditions, indicating that it is more advantageous in the 'cutting and plant' propagation of cannabis plants. In addition, the lower the plant height, the higher the space use efficiency in a multi-floor smart farm.