Enzymatically isolated American pondweed (Potamogeton nodosusPoir.) epidermal tissues were exposed to14C-labeled dichlobenil (2,6-dichlorobenzonitrile), diquat (6,7-dihydrodipyrido[1,2-α: 2′, 1′-c] pyrazinediium ion), silvex [2-(2,4,5-trichlorophenoxy) propionic acid] or 2,4-D [(2,4-dichlorophenoxy)acetic acid] at concentrations of 5 × 10−4, 5 × 10−5, and 5 × 10−610M, and the amount of herbicide crossing the tissue layer was measured. Rates of herbicide movement were compared to those found when copper sulfate pentahydrate was added as a potential synergist at concentrations of 5 × 10−5M (12.5 ppm), 5 × 10−6M (1.25 ppm), and 5 × 10−7M (0.125 ppm). Copper sulfate at 5 × 10−6M increased the rate of movement of all herbicides. However, diquat and dichlobenil exhibited the most enhanced movement in the presence of copper sulfate. Without copper sulfate, 0.1 nmoles of 5 × 10−6M14C diquat penetrated the tissue within 24 h, compared to 1.3 nmoles following the addition of 5 × 10−7M of copper sulfate.
Nowe stanowisko Potamogeton nodosus (Potamogetonaceae) w Karpatach polskich.