Table 6: Interactive effects of UV-B radiation and nitrogen on Mg concentration (mg g−1) and Mg acquired (g m−2) by above-ground organs of maize.

Nitrogen Radiation Silking Maturity Lc Sc La Sa Lc Sc Gc La Sa Ga N0 UV 2.40 2.80 0.35 0.82 3.00 2.08 a 1.22 0.49 1.30 0.82 a C 3.24 3.17 0.53 1.05 3.03 2.05 a 1.03 0.58 1.32 0.88 a Mean 2.82 2.99 B 0.44 0.94 C 3.01 2.07 1.12 0.53 B 1.31 C 0.85 C N1 UV 3.23 3.51 0.47 1.19 3.13 2.03 a 1.25 0.62 1.37 1.15 b C 4.29 3.51 0.90 1.87 3.05 1.75 a 1.12 0.75 1.68 1.39 a Mean 3.76 3.51 A 0.68 1.53 B 3.09 1.89 1.19 0.68 AB 1.53 BC 1.27 B N2 UV 2.64 2.78 0.44 1.07 3.32 2.42 a 0.96 0.73 1.84 0.98 b C 3.09 2.83 0.74 1.79 2.55 1.49 b 1.21 0.76 1.61 1.78 a Mean 2.86 2.80 B 0.59 1.43 B 2.93 1.96 1.09 0.74 A 1.73 AB 1.38 B N3 UV 2.64 3.20 0.51 1.47 3.17 2.08 a 1.17 0.74 1.84 1.30 b C 2.67 3.47 0.73 2.21 2.37 1.51 b 1.28 0.79 1.81 2.15 a Mean 2.65 3.33 A 0.62 1.84 A 2.77 1.79 1.23 0.77 A 1.82 A 1.73 A Mean UV 2.77 3.13 0.45 b 1.17 b 3.16 a 2.13 a 1.16 0.65 1.59 1.10 b C 3.32 3.24 0.73 a 1.72 a 2.75 b 1.70 b 1.16 0.72 1.60 1.56 a ANOVA Radiation (R) ns ns ** *** + ** ns ns ns *** Nitrogen (N) ns + ns ** ns ns ns + + *** R × N ns ns ns ns ns + ns ns ns **

Lc: leaf concentration; Sc: stem concentration; La: amount on leaves; Sa: amount on stems; Gc: grain concentration; Ga: amount on grains; UV: high UV-B treatment; C: ambient UV-B treatment; N0, N1, N2, N3: 0, 100, 200, and 300 kg N ha−1. Means within each N level followed by the same letter (capital letters for N effects within each column) were not significantly different at . Significance of main effects: ns: not significant, +, **, ***.