Ultraviolet-B Radiation and Nitrogen Affect Nutrient Concentrations and the Amount of Nutrients Acquired by Above-Ground Organs of Maize
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.
Nitrogen
Radiation
Silking
Maturity
Lc
Sc
La
Sa
Lc
Sc
Gc
La
Sa
Ga
N0
UV
33.0
13.4
5.1
4.0
24.7 a
3.4
15.0 a
4.1 a
2.1 a
10.0 a
C
28.6
10.9
4.8
3.5
17.4 b
3.0
11.3 b
3.4 a
2.0 a
9.5 a
Mean
30.8 B
12.2 B
4.9 C
3.8 C
21.0 B
3.2 C
13.1 B
3.7 D
2.1 C
9.8 D
N1
UV
38.2
17.0
5.6
5.8
27.0 a
3.8
13.5 b
5.4 b
2.6 b
12.4 b
C
35.1
14.0
7.3
7.4
29.1 a
5.5
16.5 a
7.1 a
5.2 a
20.6 a
Mean
36.6 A
15.5 A
6.4 B
6.6 B
28.1 A
4.7 B
15.0 A
6.2 C
3.9 B
16.5 C
N2
UV
38.1
16.5
6.2
6.4
25.8 b
5.1
14.8 a
5.6 b
3.9 b
15.1 b
C
35.5
15.8
8.4
10.0
30.5 a
6.6
15.1 a
9.0 a
7.1 a
22.6 a
Mean
36.8 A
16.2 A
7.3 B
8.2 A
28.2 A
5.8 A
15.0 A
7.3 B
5.5 A
18.8 B
N3
UV
39.6
15.8
7.9
7.2
28.0 a
5.2
13.7 b
6.6 b
4.7 b
15.3 b
C
36.3
14.2
10.0
9.1
29.6 a
5.7
16.7 a
9.8 a
6.9 a
28.1 a
Mean
37.9 A
15.0 A
8.9 A
8.2 A
28.8 A
5.5 A
15.2 A
8.2 A
5.8 A
21.7 A
Mean
UV
37.5 a
15.8 a
6.3 b
6.0 b
26.6 a
4.4 b
14.1 a
5.5 b
3.4 b
13.4 b
C
33.9 b
13.7 b
7.6 a
7.5 a
26.7 a
5.2 a
14.9 a
7.3 a
5.3 a
20.2 a
ANOVA
Radiation (R)
+
*
*
**
ns
*
ns
***
***
***
Nitrogen (N)
*
*
**
***
**
***
+
***
***
***
R × N
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; +; *; **; ***.
