Pesticide Drift

Learning Objectives

• Distinguish between pesticide drift and overspray.
• Tell what problems can arise for you and others because of
pesticide drift.
• Distinguish spray drift from vapor drift.
• Recall the 5 factors that increase spray drift and why they do so.
• Identify the most impo1tant factor affecting spray drift.
• Discuss the effects of air stability and temperature inversions on
spray drift.
• Cite clues that suggest the presence of a temperature inversion.
• Tell how you can reduce the risk of drift when applying
pesticides indoors.
• Recognize that factors which increase spray drift also increase
vapor drift.
• Discuss the effects of pesticide, temperature, and soil moisture
on vapor drift.
• State the first rule of drift management.
• Discuss site conditions you must consider before deciding to
• Be able to assess the risk of drift.
• Discuss ways you can widen the window of opportunity for
spraying so you can wait to spray until drift is less likely to
• List the 2 main considerations for reducing drift if you decide to
• Discuss factors that affect the proportion of small droplets in
pesticide spray.
• Describe advantages boom sprayers have over airblast sprayers
with respect to spray drift.
• Tell why some pesticide labels require you to apply a spray of a
defined droplet size spectrum and what factors affect that
• Explain how types of solid particles can drift and how you can
prevent them from doing so.