Submitted to: International Symposium on Adjuvants for Agrochemicals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/26/1998
Publication Date: N/A
Citation: N/A Interpretive Summary: Surfactants are added to pesticide sprays to help them stick to plant leaves. But, some surfactants can themselves cause damage to leaf tissue, depending on their chemical properties. This study was conducted to determine the effects of surfactant chemistry on the amount of spray retained on leaves, the spread of spray droplets, and damage to green foxtail leaves. We found that surfactant chemistry affected all three of these factors. The amount of spray retained on leaves was not related to leaf damage or to droplet spread. Leaf damage generally decreased with increased droplet spread. The chemistry of the surfactant determined the amount of leaf damage. The amount of spray retained on leaves determines the total amount of surfactant on a plant and the droplet spread determines the amount of surfactant per leaf area. Thus, the amount of spray retained on leaves and droplet spread determines how much surfactant is available to cause leaf damage.
Technical Abstract: Nonionic surfactants can cause foliar injury. Experiments were conducted to determine the influence of surfactant chemistry on spray retention, droplet spread and surfactant phytotoxicity to green foxtail. Lipophilic chemistry and hydrophilic:lipophilic balance (HLB) influenced surfactant phytotoxicity, spray retention, and droplet spread. Spray retention did not relate to foliar injury or to droplet spread. Within a lipophilic chemistry, foliar injury generally decreased with increased droplet spread. Lipophilic chemistry and HLB determine the innate phytotoxicity of a surfactant. Spray retention determines the total amount of surfactant on a plant and droplet spread determines the amount of surfactant/unit area. Thus, spray retention and droplet spread determines the amount of surfactant available to cause injury.