Table 7.

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

Nitrogen	Radiation	Silking				Maturity
		Lc	Sc	La	Sa	Lc	Sc	Gc	La	Sa	Ga
N0	UV	321.5	51.5 a	49.6	14.8 a	402.0	182.0	28.5	66.4	112.2	19.1 a
	C	362.0	70.0 a	60.8	23.8 a	1029.3	300.0	18.3	204.7	184.8	15.6 a
	Mean	341.8	60.8	55.2	19.3 B	715.6	241.0	23.4	135.5	148.5	17.4 C
N1	UV	367.0	102.0 a	54.8	35.4 a	363.3	228.0	25.7	70.5	155.1	23.4 a
	C	360.7	58.3 b	75.2	31.0 a	445.0	154.3	20.7	108.9	150.5	25.7 a
	Mean	363.8	80.2	65.0	33.2 A	404.2	191.2	23.2	89.7	152.8	24.6 B
N2	UV	301.5	59.5 b	50.2	23.2 b	392.5	315.5	29.5	86.3	238.3	29.9 b
	C	397.3	101.3 a	95.0	64.4 a	448.7	157.7	29.3	133.8	171.5	43.1 a
	Mean	349.4	80.4	72.6	43.8 A	420.6	236.6	29.4	110.1	204.9	36.5 A
N3	UV	375.0	84.7 a	73.1	38.8 a	504.3	281.7	26.0	119.1	231.3	28.9 b
	C	289.3	48.0 b	79.7	30.6 a	471.0	194.3	33.0	156.1	230.8	55.1 a
	Mean	332.2	66.3	76.4	34.7 A	487.7	238.0	29.5	137.6	231.0	42.0 A
Mean	UV	347.2	78.2	58.3 b	29.9	419.2	252.4	27.1	87.4 b	186.0	25.5 b
	C	352.3	69.4	77.7 a	37.4	598.5	201.6	25.3	150.9 a	184.4	34.9 a
					ANOVA
Radiation (R)		ns	ns	*	ns	ns	ns	ns	*	ns	**
Nitrogen (N)		ns	ns	ns	+	ns	ns	ns	ns	ns	***
R × N		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 P < 0.10. Significance of main effects: ns: not significant, ⁺ P < 0.1, *P < 0.05, **P < 0.01, ***P < 0.001.