Effects of Drop Size, Spray Volume, and Dosage on Paraquat Toxicity

Abstract

The effects of drop-size, dosage, and spray volume on the toxicity of aqueous sprays of paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) were measured using sunflower ( Helianthus annuus L. ‘Peredovik’). Small drops (100 μ) were more phytotoxic than large ones (350 μ), and concentrated solutions (5.5 L/ha) were more phytotoxic than dilute solutions (2.2 L/ha) at the same dosage rate.