Layering contrasting photoselective filters improves the simulation of foliar shade

Table 7 Average data collected under layered plus green (PG) and neutral density (ND) filters

Filter(s)	R:FR^a	PPE^b	B:G^c	PPF reduction^d	UV-A PF^e
				%	µmol m⁻² s⁻¹
0.15 ND^f	0.84 B^g	0.68 B	0.86 B	36.0 J	45.5 A
0.30 ND	0.61 D	0.64 E	0.88 AB	53.0 H	32.3 BC
0.60 ND	0.30 H	0.53 I	0.91 A	79.7 C	12.5 EF
1/4 PG	1.00 A	0.71 A	0.67 DE	19.0 L	39.1 AB
1/2 PG	0.96 A	0.70 A	0.63 EF	24.7 K	30.5 BC
Full PG	0.78 B	0.68 B	0.47 G	36.0 J	13.4 EF
1/4 PG
+ 0.15 ND	0.70 C	0.67 C	0.71 CD	46.7 I	24.3 CD
+ 0.30 ND	0.50 E	0.62 F	0.72 C	61.7 F	17.4 DE
+ 0.60 ND	0.26 HI	0.50 J	0.74 C	83.0 B	7.1 FG
1/2 PG
+ 0.15 ND	0.62 D	0.65 D	0.61 F	51.0 H	13.1 EF
+ 0.30 ND	0.44 F	0.60 G	0.61 F	66.7 E	10.6 EFG
+ 0.60 ND	0.22 IJ	0.48 K	0.62 F	84.3 AB	4.3 FG
Full PG
+ 0.15 ND	0.52 E	0.63 E	0.47 G	56.7 G	8.8 EFG
+ 0.30 ND	0.37 G	0.58 H	0.47 G	69.7 D	6.4 FG
+ 0.60 ND	0.19 J	0.45 L	0.49 G	86.3 A	2.5 G

^aR:FR = 655–665/725–735
^bPPE = Phytochrome photoequilibria
^cB:G = 420–490/500–570
^dPPF reduction = Percent reduction in PPF relative to full sun
^eUV-A PF = Photon flux between 340 and 399 nm
^fRosco e-colour + filters were used for both PG and ND filters
^gData are presented as averages acquired on three different clear sky or mostly sunny days between 13:00 and 14:00 h: 27 May, 30 May, and 12 June 2020. Means are only compared within column and were separated with Fisher’s LSD. Means followed by a common letter are not significantly different (P = 0.05). Data collected under full sun were on average; R:FR = 1.15, PPE = 0.72, B:G = 0.87, PPF = 1719 µmol m⁻² s⁻¹, UV-A PF = 86 µmol m⁻² s⁻¹

ISSN: 1746-4811