Table 4: Interactive effects of UV-B radiation and nitrogen on K concentration (mg g−1) and K acquired (g m−2) by above-ground organs of maize.

NitrogenRadiationSilkingMaturity
LcScLaSaLcScGcLaSaGa

N0UV21.618.03.45.523.212.6 a6.83.8 a8.14.5
C24.020.04.06.522.714.7 a6.44.4 a9.25.4
Mean22.819.03.7 B6.0 C22.913.6 A6.64.1 C8.6 B5.0 C

N1UV26.730.43.910.120.510.5 a6.74.0 a7.26.1
C18.914.43.97.618.79.1 a6.54.5 a8.78.2
Mean22.822.43.9 B8.9 BC19.69.8 B6.64.3 C8.0 B7.1 B

N2UV22.428.03.710.718.48.2 b6.04.0 b6.16.2
C21.819.25.112.220.411.7 a6.76.1 a12.810.0
Mean22.123.64.4 AB11.4 AB19.410.0 B6.35.1 B9.4 AB8.1AB

N3UV23.727.74.712.919.613.3 a6.14.6 b12.26.9
C22.420.56.213.121.610.4 a6.07.1 a12.510.1
Mean23.124.15.4 A13.0 A20.611.9 AB6.15.8 A12.4 A8.5 A

MeanUV23.926.6 a4.0 b10.220.411.3 a6.44.1 b8.7 b6.0 b
C21.818.5 b4.8 a9.920.811.5 a6.45.5 a10.8 a8.5 a

ANOVA

Radiation (R)ns * +nsnsnsns *** + ***
Nitrogen (N)nsns+ ** ns * ns ** + ***
R × Nnsnsnsnsns+ns * nsns

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 .