Ultraviolet-B Radiation and Nitrogen Affect Nutrient Concentrations and the Amount of Nutrients Acquired by Above-Ground Organs of Maize
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.
Nitrogen
Radiation
Silking
Maturity
Lc
Sc
La
Sa
Lc
Sc
Gc
La
Sa
Ga
N0
UV
21.6
18.0
3.4
5.5
23.2
12.6 a
6.8
3.8 a
8.1
4.5
C
24.0
20.0
4.0
6.5
22.7
14.7 a
6.4
4.4 a
9.2
5.4
Mean
22.8
19.0
3.7 B
6.0 C
22.9
13.6 A
6.6
4.1 C
8.6 B
5.0 C
N1
UV
26.7
30.4
3.9
10.1
20.5
10.5 a
6.7
4.0 a
7.2
6.1
C
18.9
14.4
3.9
7.6
18.7
9.1 a
6.5
4.5 a
8.7
8.2
Mean
22.8
22.4
3.9 B
8.9 BC
19.6
9.8 B
6.6
4.3 C
8.0 B
7.1 B
N2
UV
22.4
28.0
3.7
10.7
18.4
8.2 b
6.0
4.0 b
6.1
6.2
C
21.8
19.2
5.1
12.2
20.4
11.7 a
6.7
6.1 a
12.8
10.0
Mean
22.1
23.6
4.4 AB
11.4 AB
19.4
10.0 B
6.3
5.1 B
9.4 AB
8.1AB
N3
UV
23.7
27.7
4.7
12.9
19.6
13.3 a
6.1
4.6 b
12.2
6.9
C
22.4
20.5
6.2
13.1
21.6
10.4 a
6.0
7.1 a
12.5
10.1
Mean
23.1
24.1
5.4 A
13.0 A
20.6
11.9 AB
6.1
5.8 A
12.4 A
8.5 A
Mean
UV
23.9
26.6 a
4.0 b
10.2
20.4
11.3 a
6.4
4.1 b
8.7 b
6.0 b
C
21.8
18.5 b
4.8 a
9.9
20.8
11.5 a
6.4
5.5 a
10.8 a
8.5 a
ANOVA
Radiation (R)
ns
*
+
ns
ns
ns
ns
***
+
***
Nitrogen (N)
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; +; *; **; ***.
