Low relative humidity and/or high temperatures ______ the potential for spray drift.

Low relative humidity and/or high temperatures ______ the potential for spray drift.

• A. Decrease
• B. Do not affect
• C. Increase
• D. Unrelated

Answer: (C)

Droplet evaporation drives drift more than anything else here. When relative humidity is low and temperatures are high, water in the spray evaporates quickly. That makes droplets shrink and become lighter, so they’re more easily carried by wind and stay in the air longer. The result is a greater distance that spray can travel away from the target. While some pesticides may volatilize more in heat, the main reason drift increases under these conditions is the creation of smaller, more drift-prone droplets. So, drift potential increases in dry, hot conditions.

Droplet evaporation drives drift more than anything else here. When relative humidity is low and temperatures are high, water in the spray evaporates quickly. That makes droplets shrink and become lighter, so they’re more easily carried by wind and stay in the air longer. The result is a greater distance that spray can travel away from the target. While some pesticides may volatilize more in heat, the main reason drift increases under these conditions is the creation of smaller, more drift-prone droplets. So, drift potential increases in dry, hot conditions.