Special Precautions when using herbicide Flashcards
What is the difference between particle drift and vapor drift?
Particle drift involves the off-target movement of spray droplets or dust particles, while vapor drift
involves the movement of pesticide that has volatilized (turned into a gaseous state).
What weather conditions are likely to produce particle drift?
Hot and dry conditions can quickly evaporate the water from large pesticide droplets, turning them
into much smaller droplets that are more likely to drift.
Temperature inversions are particularly
dangerous for drift because …. .
droplets can remain suspended for a long time.
Name three factors that affect herbicide leaching.
Strength of adsorption to soil particles, solubility in water, chemical persistence.
Why should pesticide spray formulations that go into suspension not be left standing without
agitation?
The herbicide could settle out and cake in the bottom of the tank, making cleaning very difficult; while resulting uneven or inadequate dosage for effective control.
What are some important precautions to take when using bare-ground or residual herbicides?
In general, be extra careful! Know the soil type prior to making the application. Do not mix, apply, or clean spray equipment
near wells, areas with shallow water tables, or other bodies of water. Understand the influence of
rain and irrigation. Do not apply these types of pesticides where the root systems of desirable
vegetation may be present or may extend in the future. Do not apply to frozen or saturated ground,
and avoid spray drift during application. Use extreme caution when applying pesticides to slopes,
and take measures to prevent humans, animals, and equipment from moving treated soil from the
area.
What is photodegradation?
The breakdown of herbicides when they are exposed to sunlight.
What are five other ways pesticides can be degraded or removed from the soil?
Microbial degradation chemical degradation adsorption to soil and organic matter volatilization removal by plants
