Table 6.
Herbicide concentrations (ng/L) in April/May and July reservoir water samples, number of paired comparisons, and statistical p-values.
| Pesticide | April/May (mean ± SE) | July (mean ± SE) | No. of paired samples | p-Value |
|---|---|---|---|---|
| Significantly greater in July | ||||
| Bromoxynil | 1.5 ± 0.3 | 29.6 ± 12.5 | 36 | < 0.001 |
| MCPA | 36.5 ± 8.7 | 89.1 ± 13.8 | 42 | < 0.001 |
| Diclorprop | 9.1 ± 2.9 | 16.7 ± 3.1 | 40 | < 0.001 |
| Dicamba | 11.3 ± 4.9 | 42.9 ± 26.0 | 39 | < 0.001 |
| 2,4-D | 78.9 ± 20.2 | 147.2 ± 43.9 | 42 | < 0.001 |
| Clopyralid | 26.1 ± 6.3 | 55.8 ± 24.8 | 42 | 0.001 |
| Not significant | ||||
| Mecoprop | 6.1 ± 1.3 | 8.4 ± 2.3 | 42 | 0.08 |
| Tribenuron | 1.3 ± 0.2 | 4.9 ± 2.5 | 12 | 0.18 |
| Ethametsulfuron | 6.9 ± 1.9 | 8.5 ± 4.4 | 18 | 0.88 |
| Imazamethabenz A | 6.4 ± 1.7 | 22.2 ± 13.6 | 15 | 0.98 |