Georgia Pest Control Practice Test

Which of the following pesticide formulations may cause harm to plants (phytotoxicity)?

1. Emulsifiable concentrates

2. Microencapsulated

3. Wettable powders

4. Dusts

The correct answer is: Emulsifiable concentrates

Emulsifiable concentrates can indeed cause harm to plants, known as phytotoxicity, primarily due to their formulation which allows them to dissolve in oils or organic solvents. This causes a higher concentration of active ingredients that can be more easily absorbed by plant tissues, leading to potential damage such as leaf burn or other physiological disorders. Phytotoxic reactions often occur especially when the pesticides are applied under conditions that promote uptake, like high temperatures or humidity. Other formulations, while they may have specific benefits or drawbacks, generally have lower risks of causing phytotoxicity. Microencapsulated pesticides are designed to release their active ingredients slowly, which minimizes immediate plant contact and reduces the chances of phytotoxicity. Wettable powders are mixed with water to create a spray and may have reduced plant absorption compared to emulsifiable concentrates. Dust formulations are typically used for surface applications and may not penetrate plant tissues in a way that would lead to phytotoxic effects. Thus, emulsifiable concentrates are particularly noted for the potential harm they can inflict on plants due to their chemical properties and formulation.