New Experience with Formulations for ULV Application1

For economical and environmental reasons, new application methods and formulations of pesticides are continually being tested. Amongst the application methods, aerial ULV spraying is becoming more and more important. There are two main fields for aerial ULV application: crop and non-crop spraying. Non-crop spraying is widely used for locust, mosquito and tsetse control. ULV formulations used for these purposes must be specially designed due to the extraordinary conditions in which they are applied. The choice of solvent, which should have a certain dissolving power, will determine the viscosity, volatility and phytotoxicity of the formulation. Because the positive and negative physical properties of the available solvents are sometimes inversely related, a suitable formulation is always a compromise. As an example, the physical properties of two endosulfan ULV formulations for crop spraying and non-crop spraying (tsetse control) are discussed.