production and respiration decreased in the microcosm with even a 1 mg/L addition,
and effects were observed. The influence on the amount of production decreasing to
0 occurred at an addition concentration of 10 mg/L, and it was clear that TCP more
strongly influences production than respiration (Fig. 7.6). As a result of holding P
and R constant, a test of the significant difference in the P/R ratio was performed
using a branching-type ANOVA. Having been subjected to impact assessment, MCP
was found, and the m-NOEC was determined to be 1 mg/L. Additionally, as a result
of having compared the mesocosm and microcosm test results, it was clear that they
were closely correlated.
7.2.2 Mancozeb
Mancozeb was added to the microcosm N-system at concentrations of 0.3 and
3.0 mg/L 16 days after cultivation began (i.e., during the stationary phase). It was
determined that there was a statistically significant difference in both the 0.3 and
3 mg/L loads of Mancozeb. However, the lowest effective concentration was
determined because it maintained almost stable production and respiration volumes
at 0.3 mg/L of added Mancozeb (Fig. 7.7).
1
2
3
4
5
6 7
8
9
1 0
1 1 1 2
1 3
1 4
1
2
3
4
5
6 7
8
9
1 0
1 1 1 2
1 3
1 4
control
0.125mg/L
0.25mg/L
1
2
3
4
5
6
7
8
9
10
11
12
13
14
0.5 mg/L
1
2
3
4
5
6
7
8
9
10
11
1 2
13
14
1 mg/L
1
2
3
4
5
6
7
8
9
1 0
1 1
1 2
1 3
1 4
10mg/L
Production(mg O
2 /L)
Respiration(mg O 2 /L)
9
6
3
0
9
6
3
0
9
6
3
0
9
6
3
0
9
6
3
0
9
6
3
0
9
6
3
0
9
6
3
0
9
6
3
0
9
6
3
0
2 7
27
18
18
9
9
0
0
Fig. 7.6 Time course of P/R ratio in 2,3,4,6-TCP-added microcosm N-system
80
K. Murakami et al.