The highest plants were under module where the main LEDs were combined
with supplemental 520 nm light and the shorter ones were cultivated under module with
supplemental UV 380 nm LEDs (Fig. 1). Significantly lower hypocotyls were in cucum-
ber transplants under module with the main set of LEDs, under modules with supple-
mental green and orange light (Fig. 3). Internodes length of plants under high-power
solid-state lighting modules with supplemental illumination by UV (380 nm) LEDs were
the shortest. The longest internodes were in plants under module with supplemental
520 nm light (L3) (Fig. 3). But these plants had the most (~5) fully expanded leaves
(Fig. 4), so their fourth internodes could be grown up completely. Similar trends were
noticed in cucumber transplants under module with the main set of LEDs, and under
modules with supplemental 622 nm LEDs. Meanwhile, plants under “SON-T Agro”,
under modules with supplemental UV 380 nm and 595 nm LEDs had almost one fully
expanded leaf less than the plants mentioned above (Fig. 4), and their fourth internodes
were shorter (Fig. 3).