Growth, Physiology, and Root Development in Seedlings of Woody Species Treated with a Seaweed Extract

(A, D, G, J, M) Root dry weight (DW_Roots [g]); (B, E, H, K, N) specific root length (SRL [m g⁻¹]); and (C, F, I, L, O) total root length (TRL [cm]) of 5 woody species: Amelanchier ovalis (AOV); Carpinus betulus (CBE); Crataegus monogyna (CMO); Fagus sylvatica (FSY); and Ligustrum vulgare (LVU) at 2 weeks (A, B, C), 9 weeks (D, E, F), 15 weeks (G, H, I), 30 weeks (J, K, L), and 80 weeks (M, N, O) after seedling emergence. Different letters indicate significant differences among species within each sampling date at P < 0.01, n.s. = P > 0.05.

Effect of biostimulant dose (D0 = no application; D1 = 1 kg m⁻³; D2 = 2 kg m⁻³; D3 = 3 kg m⁻³) on (A) average total root length (TRL [cm]); (B) root dry weight (DW_roots [g]); and (C) specific root length (SRL [m g⁻¹]) measured at 2 weeks, 9 weeks, 15 weeks, 30 weeks, and 80 weeks after seedling emergence. Different letters indicate significant differences among doses within each sampling date at P < 0.01, n.s. = P > 0.05.

Effect of biostimulant dose (D0 = no application; D1 = 1 kg m⁻³; D2 = 2 kg m⁻³; D3 = 3 kg m⁻³) on (A) average total plant dry weight (DW_plant [g]); (B) relative growth rate of the whole plant (RGR_plant [mg g⁻¹ day⁻¹]); and (C) total leaf area (TLA [cm²]) measured at 2 weeks, 9 weeks, 15 weeks, 30 weeks, and 80 weeks after seedling emergence. Different letters indicate significant differences among doses within each sampling date at P < 0.01, n.s. = P > 0.05.

Effects of species Amelanchier ovalis (AOV); Crataegus monogyna (CMO); Carpinus betulus (CBE); Fagus sylvatica (FSY); and Ligustrum vulgare (LVU) and biostimulant dose (D0 = no application; D1 = 1 kg m⁻³; D2 = 2 kg m⁻³; D3 = 3 kg m⁻³) on (A, C) root to shoot ratio (R:S [g g⁻¹]) and on (B, D) the ratio between total leaf area (TLA) and total root length (TRL)(cm² cm⁻¹) measured at 2 weeks, 9 weeks, 15 weeks, 30 weeks, and 80 weeks after seedling emergence. Different letters indicate significant differences among species (A, B) and doses (C, D) within each sampling date at P < 0.01, n.s. = P > 0.05.

Effect of biostimulant dose (D0 = no application; D1 = 1 kg m⁻³; D2 = 2 kg m⁻³; D3 = 3 kg m⁻³) on (A, B, C) transpiration per unit of leaf area (E [mmol m⁻² s⁻¹]) and (D, E, F) net CO₂-assimilation (A [μmol m⁻² s⁻¹]) measured in Carpinus betulus (A, D), Crataegus monogyna (B, E), and Fagus sylvatica (C, F) during June 2021, July 2021, October 2021, June 2022 and September 2022. Different letters indicate significant differences among doses within each sampling date at P < 0.01, n.s. = P > 0.05.

Effect of biostimulant dose (D0 = no application; D1 = 1 kg m⁻³; D2 = 2 kg m⁻³; D3 = 3 kg m⁻³) on the drawdown of CO₂ from (A, B, C) the outer air to the substomatal chamber (Ca-Ci [ppm]), from (D, E, F) the substomatal chamber to the sites of carboxylation (Ci-Cc [ppm]), and on (G, H, I) leaf greenness index (SPAD) measured in Carpinus betulus (A, D, G), Crataegus monogyna (B, E, H), and Fagus sylvatica (C, F, I) in 2021 and 2022. Different letters indicate significant differences among doses within each sampling date at P < 0.01, n.s. = P > 0.05.