ODA PESTICIDE EXAM RIGHT-OF-WAY (GENERAL
INFORMATION) EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED LATEST UPDATE
Environmental influences on herbicide availability:
Soil properties and climatic factors, such as temperature, humidity, and precipitation are
the dominant factors that affect herbicide performance.
Drift:
pesticide movement through the air to areas not intended for treatment
Particle drift:
when herbicides are applied as sprays, air currents acting on the suspended spray
droplets can carry some spray through the atmosphere beyond the intended target
Vapor drift:
when certain herbicides volatilize (change to a gaseous form), producing fumes that
may cause damage.
Factors that affect drift:
High temperature and low relative humidity may cause spray droplets to rapidly
evaporate into smaller droplets that are more likely to drift.
The potential for volatilization increases as:
temperature increases and humidity decrease
Environmental Hazard section:
, • Herbicides with a known potential to leach through the soil profile have a groundwater
advisory statement in the "Environmental Hazard" section of the product label
• Read this section of the label
Characteristics that affect leaching:
• Strength of adsorption to soil particles
• Solubility in water
• Persistence
Runoff:
usually is not excessive unless soil erosion occurs or the product is applied to frozen
ground
Sand:
• Coarse and does not have many charge or binding sites.
• Sand has less surface area for the same volume of soil than silt or clay; therefore,
fewer adsorptive sites are available.
• Lower herbicide rates generally are used on sandy soils.
Silt:
• more adsorptive sites than sand but many times fewer than clay and organic matter.
• Medium application rates often are listed on the label
Clay:
• fine and has a large surface area per given volume of soil, resulting in more adsorptive
sites than sand or silt.
• Higher use rates are listed on the label
Organic matter (OM):
INFORMATION) EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED LATEST UPDATE
Environmental influences on herbicide availability:
Soil properties and climatic factors, such as temperature, humidity, and precipitation are
the dominant factors that affect herbicide performance.
Drift:
pesticide movement through the air to areas not intended for treatment
Particle drift:
when herbicides are applied as sprays, air currents acting on the suspended spray
droplets can carry some spray through the atmosphere beyond the intended target
Vapor drift:
when certain herbicides volatilize (change to a gaseous form), producing fumes that
may cause damage.
Factors that affect drift:
High temperature and low relative humidity may cause spray droplets to rapidly
evaporate into smaller droplets that are more likely to drift.
The potential for volatilization increases as:
temperature increases and humidity decrease
Environmental Hazard section:
, • Herbicides with a known potential to leach through the soil profile have a groundwater
advisory statement in the "Environmental Hazard" section of the product label
• Read this section of the label
Characteristics that affect leaching:
• Strength of adsorption to soil particles
• Solubility in water
• Persistence
Runoff:
usually is not excessive unless soil erosion occurs or the product is applied to frozen
ground
Sand:
• Coarse and does not have many charge or binding sites.
• Sand has less surface area for the same volume of soil than silt or clay; therefore,
fewer adsorptive sites are available.
• Lower herbicide rates generally are used on sandy soils.
Silt:
• more adsorptive sites than sand but many times fewer than clay and organic matter.
• Medium application rates often are listed on the label
Clay:
• fine and has a large surface area per given volume of soil, resulting in more adsorptive
sites than sand or silt.
• Higher use rates are listed on the label
Organic matter (OM):
