*4.1. Growth Chamber Setup*

The study was conducted in a 4.4 m wide and 4.1 m long walk-in growth chamber. Cooling was provided using a top-mount refrigeration system and a dehumidifier maintained the relative humidity inside the growth chamber. The CO<sup>2</sup> level inside the growth chamber was measured and maintained by triggering a solenoid valve to open and release CO<sup>2</sup> from a compressed gas cylinder for 1-second intervals, whenever the CO<sup>2</sup> concentration dropped below 800 µmol mol−<sup>1</sup> , using a CO<sup>2</sup> transmitter (GMC20; Vaisala, Helsinki, Finland) and a datalogger (CR6, Campbell Scientific, Logan, UT, USA). Temperature and relative humidity measurements were collected every ten seconds with a probe (HMP50; Vaisala) connected to the datalogger. Using those temperature and relative humidity values, vapor pressure deficit (VPD) was calculated. Average temperature, CO<sup>2</sup> level, and VPD inside the growth chamber were 24.2 <sup>±</sup> 0.2 ◦C, 825 <sup>±</sup> <sup>38</sup> <sup>µ</sup>mol mol−<sup>1</sup> , and 1.4 ± 0.12 kPa (mean ± SD), respectively.

The growth chamber contained three 2.4 m long × 0.6 m wide × 2.2 m high metal shelving racks with 0.9 m distance between the racks. Each rack had three shelves with a 0.6 m × 2.4 m ebb-and-flow tray on each shelf. Each tray had an individual irrigation tube connected to a submersible pump. Those pumps were submerged in a fertigation tank located under the bottom shelf of each of the three metal racks. Three pumps were submerged in each fertigation tank. Each ebb-and-flow tray was divided into two 1.2 m long sections. Therefore, each rack had six 1.2 m long × 0.6 m wide × 0.6 m high sections, for a total of 18 growing sections. Each growing section had two 1.1 m-long white LED lights (RAY series with Physiospec indoor spectrum; Fluence Bioengineering, Austin, TX, USA) hanging 0.4 m above the bottom of the ebb & flow tray. Air circulation was provided by four 4 <sup>×</sup> 4 cm<sup>2</sup> fans in each growing section.
