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

NitrogenRadiationSilkingMaturity
LcScLaSaLcScGcLaSaGa

N0UV33.013.45.14.024.7 a3.415.0 a4.1 a2.1 a10.0 a
C28.610.94.83.517.4 b3.011.3 b3.4 a2.0 a9.5 a
Mean30.8 B12.2 B4.9 C3.8 C21.0 B3.2 C13.1 B3.7 D2.1 C9.8 D

N1UV38.217.05.65.827.0 a3.813.5 b5.4 b2.6 b12.4 b
C35.114.07.37.429.1 a5.516.5 a7.1 a5.2 a20.6 a
Mean36.6 A15.5 A6.4 B6.6 B28.1 A4.7 B15.0 A6.2 C3.9 B16.5 C

N2UV38.116.56.26.425.8 b5.114.8 a5.6 b3.9 b15.1 b
C35.515.88.410.030.5 a6.615.1 a9.0 a7.1 a22.6 a
Mean36.8 A16.2 A7.3 B8.2 A28.2 A5.8 A15.0 A7.3 B5.5 A18.8 B

N3UV39.615.87.97.228.0 a5.213.7 b6.6 b4.7 b15.3 b
C36.314.210.09.129.6 a5.716.7 a9.8 a6.9 a28.1 a
Mean37.9 A15.0 A8.9 A8.2 A28.8 A5.5 A15.2 A8.2 A5.8 A21.7 A

MeanUV37.5 a15.8 a6.3 b6.0 b26.6 a4.4 b14.1 a5.5 b3.4 b13.4 b
C33.9 b13.7 b7.6 a7.5 a26.7 a5.2 a14.9 a7.3 a5.3 a20.2 a

ANOVA

Radiation (R)+ * * ** ns * ns *** *** ***
Nitrogen (N) * * ** *** ** *** + *** *** ***
R × Nnsnsnsns * 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 𝑃 < 0 . 1 0 . Significance of main effects: ns: not significant; + 𝑃 < 0 . 1 ; * 𝑃 < 0 . 0 5 ; ** 𝑃 < 0 . 0 1 ; *** 𝑃 < 0 . 0 0 1 .