When is the greatest potential for spray drift?

When is the greatest potential for spray drift?

• A. During rainfall events
• B. At night when dew forms
• C. When wind velocity is greater than 10 mph or when wind is blowing toward sensitive plants or critical areas
• D. When wind velocity is less than 5 mph

Answer: (C)

The main factor driving spray drift is air movement: droplets are carried by wind after they leave the nozzle, so stronger and directional winds push droplets farther off target. When wind velocity is over about 10 mph, droplets can travel much farther, and if that wind is blowing toward sensitive plants or critical areas, the potential for off-target damage is even greater. That combination—fast wind plus direction toward valuable or vulnerable targets—creates the greatest drift risk. Rainfall doesn’t inherently increase the distance droplets travel; it can interfere with deposition and wash things off, while nighttime conditions like dew can be associated with temperature inversions that sometimes affect drift in complex ways, but they don’t produce as large a drift potential as strong, directed winds. Very light winds (under 5 mph) actually reduce drift. To minimize drift, applications are typically avoided in windy conditions or directed away from sensitive areas, and drift-reducing practices are used.

The main factor driving spray drift is air movement: droplets are carried by wind after they leave the nozzle, so stronger and directional winds push droplets farther off target. When wind velocity is over about 10 mph, droplets can travel much farther, and if that wind is blowing toward sensitive plants or critical areas, the potential for off-target damage is even greater. That combination—fast wind plus direction toward valuable or vulnerable targets—creates the greatest drift risk.

Rainfall doesn’t inherently increase the distance droplets travel; it can interfere with deposition and wash things off, while nighttime conditions like dew can be associated with temperature inversions that sometimes affect drift in complex ways, but they don’t produce as large a drift potential as strong, directed winds. Very light winds (under 5 mph) actually reduce drift. To minimize drift, applications are typically avoided in windy conditions or directed away from sensitive areas, and drift-reducing practices are used.