Can Soil Compaction Alter Morphophysiological Responses and Soybean Yield under Application of Selective Herbicides?
Table 4
Mean values for the relative index of chlorophyll a and b, carbon assimilation rate (A), transpiration rate (E), shoot and root dry mass, instantaneous water use efficiency (EiUA), and shoot/root dry mass ratio in soybean plants as a function of soil physical condition and preemergence herbicide application.
Treatments
Dose (g·ha−1)
Relative index of chlorophyll a
Relative index of chlorophyll b
Compacted
Noncompacted
Compacted
Noncompacted
Control
—
28.20
32.46
6.60 Aa
6.56 Aa
Clomazone
800
30.42
29.08
6.62 Aa
6.58 Aa
Diclosulam
29.4
27.96
30.54
6.02 Aab
6.66 Aa
Flumioxazin
60
26.54
29.26
6.66 Aa
6.32 Aa
S-metolachlor
1,440
21.40
32.10
5.16 Bb
6.94 Aa
[Imazethapyr + flumioxazin]
[106 + 50]
28.02
31.30
6.46 Aab
7.60 Aa
[Pyroxasulfone + flumioxazin]
[90 + 60]
28.58
26.74
6.98 Aa
6.70 Aa
[Sulfentrazone + diuron]
[210 + 420]
29.06
31.86
5.98 Aab
6.66 Aa
Mean
27.27 B
30.41 A
6.25
6.75
A (µmol CO2·m−2·s−1)
E (mmol H2O m−2·s−1)ns
Control
—
21.74
22.18
3.10
2.84
Clomazone
800
17.22
23.04
2.72
2.94
Diclosulam
29.4
19.04
24.14
2.76
2.96
Flumioxazin
60
21.90
23.92
2.86
3.26
S-metolachlor
1,440
20.46
20.02
3.22
2.88
[Imazethapyr + flumioxazin]
[106 + 50]
20.70
24.48
3.00
3.34
[Pyroxasulfone + flumioxazin]
[90 + 60]
19.08
21.74
2.50
3.32
[Sulfentrazone + diuron]
[210 + 420]
19.70
22.64
3.18
3.08
Mean
19.98 B
22.77 A
2.91
3.08
Shoot dry mass (g)ns
Root dry mass (g)
Control
—
11.75
11.85
2.59 Ba
6.19 Aa
Clomazone
800
11.43
11.82
1.15 Ba
3.70 Ab
Diclosulam
29.4
11.74
11.68
1.48 Ba
4.42 Aab
Flumioxazin
60
11.86
9.34
1.20 Ba
3.97 Ab
S-metolachlor
1,440
11.19
11.67
1.57 Ba
3.81 Ab
[Imazethapyr + flumioxazin]
[106 + 50]
11.38
11.50
0.91 Ba
4.07 Ab
[Pyroxasulfone + flumioxazin]
[90 + 60]
11.77
12.21
1.30 Aa
2.81 Ab
[Sulfentrazone + diuron]
[210 + 420]
11.54
11.66
0.73 Ba
3.95 Ab
Mean
11.59
11.50
1.37
4.12
EiUA
Shoot/root dry mass ratio
Control
—
7.10
7.91
4.66
2.06
Clomazone
800
6.08
7.71
11.01
7.75
Diclosulam
29.4
6.81
8.27
14.72
3.53
Flumioxazin
60
7.50
7.34
11.27
3.76
S-metolachlor
1,440
6.40
6.87
17.15
4.85
[Imazethapyr + flumioxazin]
[106 + 50]
6.87
7.33
15.49
5.13
[Pyroxasulfone + flumioxazin]
[90 + 60]
7.37
6.66
18.17
9.99
[Sulfentrazone + diuron]
[210 + 420]
6.44
7.36
18.18
3.81
Mean
6.82 B
7.43 A
13.83 B
5.11 A
nsNonsignificant by F-test (). Mean values followed by different uppercase letters, in the same row, and lowercase letters, in the same column, are significantly different by the LSD-Fisher test ().
