Table 3. The persistence ratio of half-lives between each treatment relative to “control” (dark, no sediment) conditions.

The superscripts a,b,c,d represent significantly different ratios as calculated for and described in Table 2.

Herbicide	Dark no sediment	Light no sediment	Dark with sediment	Light with sediment
Diuron	1.00 a	0.81 b	0.56 c	0.28 d
Atrazine	1.00 a	1.1 a	0.67 b	0.36 c
Hexazinone	1.00 a	0.59 b	0.51 b	0.10 c
Tebuthiuron	1.00 a	1.89 b	0.83 a	0.53 c
Metolachlor	1.00 a	0.63 b	0.70 b	0.22 c
2,4-D	1.00 a	33 b	0.95 a	4.9 c