Influence of Simazine on Apparent Photosynthesis of Aquatic Plants and Herbicide Residue Removal from Water

Abstract
Simazine (2-chloro-4,6-bis(ethylamino)-s-triazine) at 0.12 to 1.0 ppmw in nutrient cultures of common duckweed (Lemna minor L.), elodea (Elodea canadensis Michx.), and parrotfeather (Myriophyllum brasiliense Camb.) inhibited oxygen evolution within 24 hr. Of the plants studied, the submersed form of parrotfeather exhibited the greatest reduction in apparent photosynthesis as measured by dissolved oxygen in the water. Simazine in nutrient culture without plants remained relatively stable during the treatment period; a slight, but not significant, diminution of chemical was detected after 4 days. Each species, elodea or emersed parrotfeather, reduced the concentration of simazine in solution within 48 hr after treatment.