Illinois Field Crop Applicators Practice Test

Dicamba and 2,4-D are known for which type of drift?

1. Particle drift

2. Vapor drift

3. Inversion drift

4. Soil drift

The correct answer is: Vapor drift

Dicamba and 2,4-D are particularly known for vapor drift, which occurs when these herbicides evaporate from treated areas and move through the air to unintended locations. This is especially relevant under specific environmental conditions, such as high temperatures and low humidity, which can enhance the volatility of these chemicals. When they vaporize, the particles can travel significant distances, posing risks to sensitive crops and non-target areas. Understanding vapor drift is crucial for applicators to minimize negative impacts on the environment and neighboring farms, ensuring they follow proper application practices to mitigate such risks. The other types of drift mentioned are less applicable; particle drift usually refers to small droplets that are carried by wind at the time of application, inversion drift is related to temperature inversions that can trap volatile substances close to the ground, and soil drift typically pertains to erosion or movement of soil rather than airborne herbicide movement.