What are two major considerations in regard to preventing drift?

• A. Wind speed and direction, and pesticide particle size
• B. Temperature and humidity
• C. Time of day and day of week
• D. Tank mix order

Answer: (B)

Preventing drift hinges on how environmental conditions influence spray droplets after they leave the nozzle. Temperature and humidity shape what happens to droplets in the air, which directly affects how far they can travel.

Higher temperatures create more vigorous air movement (convection) and speed up evaporation. As the solvent evaporates, droplets become smaller, lighter, and more easily carried off target by even modest air currents. This increases drift potential. Likewise, lower humidity accelerates evaporation, making droplets shrink more quickly and behave like fine mist that can drift farther.

In cooler, more humid conditions, evaporation slows, droplets stay larger, and they tend to settle more readily, reducing drift risk. While wind speed and direction and droplet size also matter, temperature and humidity set the baseline for how droplets behave in the air and thus are two major considerations when aiming to prevent drift.