*3.2. Effect of Light Quality on Resource Usage Efficiency*

Figure 5A shows the WUE for the three LED illumination spectra. The WUE for the W\*-, BR\*- and BRF\*-illuminated tents are 13 g FW L−<sup>1</sup> H2O, 18 g FW L−<sup>1</sup> H2O, and 24 g FW L−<sup>1</sup> H2O.

**Figure 5.** Effect of the different LED illumination spectra on the mean values of (**A**) water use efficiency (WUE) and (**B**) energy use efficiency (EUE) of sweet basil (*Ocimum basilicum* L.) plant grown in 2 m<sup>2</sup> tents. Different letters indicate a significant difference among the treatments, *p* ≤ 0.05.

Note that the uniformity of photosynthetic photon flux (PPF) is crucial for indoor plant growth. This prevents photons from being spread over, reducing energy consumption by improving their utilization inside the grow tent. The energy use efficiencies (EUE) is defined as the average biomass produced per unit of electrical energy used for plant illumination.

The energy use efficiencies (EUE) for the three LED illumination spectra are shown in Figure 5B, revealing that the EUE for the W\*-, BR\*- and BRF\*-illuminated tents are <sup>46</sup> <sup>±</sup> 1.7 g FW kW−<sup>1</sup> , <sup>65</sup> <sup>±</sup> 8.6 g FW kW−<sup>1</sup> , and 80 <sup>±</sup> 4.8 g FW kW−<sup>1</sup> . Here the BRF\* spectrum yielded a significantly higher EUE than that of the W\* spectrum.
