WASHINGTON PESTICIDE LAWS COMPREHENSIVE EXAMS
QUESTIONS AND ANSWERS 2025/2026 ALL RATED A+
✔✔Contact Herbicides - ✔✔Generally applied directly to plant foliage and kill only plant
parts they directly contact. They do not translocate (move) throughout a plant. Damage
often shows in a matter of hours after application. Even herbicide distribution is key to
kill entire weed.
✔✔Translocated Herbicides - ✔✔Are absorbed through the foliage or shoots and move
throughout the plant. These herbicides move with the water and sugars to roots or
growing parts of plant where damage occurs.
✔✔Growth Regulators - ✔✔Disrupt the hormone balance and protein synthesis in
plants, causing growth abnormalities. Selectively kills broadleaf weeds in range and
crop grasses.
✔✔Growth Regulator Chemical Families - ✔✔Phenoxy acetic acids (2,4-D),
Benzoic acids (Banvel),
Pyridines (Tordon).
✔✔Amino Acid Synthesis Inhibitors - ✔✔Prevent the production of amino acids that
form proteins fundamental to normal plant development. Translocate through the plant
from foliar or soil applications.
✔✔Amino Acid Synthesis Chemical Families - ✔✔Sulfonylureas (Harmony),
Imidazolinones (Pursuit),
Amino Acid Derivatives (Roundup).
✔✔Lipid Inhibitors - ✔✔Prevent the production of fatty acids which are used to make
cell membranes and required for new plant growth. They translocate through the plant
from foliar applications.
✔✔Lipid Inhibitors Chemical Families - ✔✔Cyclohexanediones (Select),
Aryloxyphenoxypropionates (Hoelon).
✔✔Seedling Growth Inhibitors - ✔✔Interfere with new plant growth, stopping normal
seedling root or shoot development. They must be applied to to the soil to act on
emerging weed seedlings.
✔✔Seedling Growth Chemical Families - ✔✔Dinitroanilines (Treflan),
Acetanilides (Dual),
Thiocarbamates (Far-Go).
, ✔✔Photosynthesis Inhibitors - ✔✔Interfere with photosynthesis (conversion of water
and carbon dioxide to sugar in the presence of sunlight), resulting in a buildup of toxic
products. These herbicides are normally root or foliar absorbed.
✔✔Photosynthesis Inhibitors Chemical Families - ✔✔Triazines (Sencor),
Phenylureas (Lorox),
Uracils (Sinbar),
Benzothiadiazoles (Basagran),
Nitriles (Buctril).
✔✔Cell Membrane Disruptors - ✔✔Destroy plant tissue by rupturing plant cell
membranes. These contact herbicides have no mobility in the plant and must be applied
post-emergence.
✔✔Cell Membrane Chemical Families - ✔✔Bipyridyliums (Gramoxone),
Diphenyl Ethers (Blazer).
✔✔Pigment Inhibitors - ✔✔prevents plants from forming chlorophyll that is essential for
photosynthesis. These soil applied herbicides translocate to plant leaves.
✔✔Pigment Inhibitors Chemical Families - ✔✔Isoxazolidinones (Command),
Pyridazinones (Solicam).
✔✔Selective Herbicides - ✔✔A herbicide that kills one type of plant but does not
seriously affect other types of plants.
✔✔Nonselective Herbicides - ✔✔Herbicides that kill/control most or all plants.
✔✔Pre-Emergence Treatment - ✔✔A treatment made prior to emergence of a crop or
weed.
✔✔Post-Emergence Treatment - ✔✔Any treatment made after emergence of a
specified crop or weed.
✔✔GPA - ✔✔5940 x nozzle output GPM/ MPH x nozzle spacing inches
✔✔Amount ai - ✔✔Amount Product x % ai
✔✔Amount Product - ✔✔Amount ai / % ai
✔✔lbs ai - ✔✔Gal Product x lb ai/gal
✔✔Gal Product - ✔✔lbs ai / lb ai per gallon
QUESTIONS AND ANSWERS 2025/2026 ALL RATED A+
✔✔Contact Herbicides - ✔✔Generally applied directly to plant foliage and kill only plant
parts they directly contact. They do not translocate (move) throughout a plant. Damage
often shows in a matter of hours after application. Even herbicide distribution is key to
kill entire weed.
✔✔Translocated Herbicides - ✔✔Are absorbed through the foliage or shoots and move
throughout the plant. These herbicides move with the water and sugars to roots or
growing parts of plant where damage occurs.
✔✔Growth Regulators - ✔✔Disrupt the hormone balance and protein synthesis in
plants, causing growth abnormalities. Selectively kills broadleaf weeds in range and
crop grasses.
✔✔Growth Regulator Chemical Families - ✔✔Phenoxy acetic acids (2,4-D),
Benzoic acids (Banvel),
Pyridines (Tordon).
✔✔Amino Acid Synthesis Inhibitors - ✔✔Prevent the production of amino acids that
form proteins fundamental to normal plant development. Translocate through the plant
from foliar or soil applications.
✔✔Amino Acid Synthesis Chemical Families - ✔✔Sulfonylureas (Harmony),
Imidazolinones (Pursuit),
Amino Acid Derivatives (Roundup).
✔✔Lipid Inhibitors - ✔✔Prevent the production of fatty acids which are used to make
cell membranes and required for new plant growth. They translocate through the plant
from foliar applications.
✔✔Lipid Inhibitors Chemical Families - ✔✔Cyclohexanediones (Select),
Aryloxyphenoxypropionates (Hoelon).
✔✔Seedling Growth Inhibitors - ✔✔Interfere with new plant growth, stopping normal
seedling root or shoot development. They must be applied to to the soil to act on
emerging weed seedlings.
✔✔Seedling Growth Chemical Families - ✔✔Dinitroanilines (Treflan),
Acetanilides (Dual),
Thiocarbamates (Far-Go).
, ✔✔Photosynthesis Inhibitors - ✔✔Interfere with photosynthesis (conversion of water
and carbon dioxide to sugar in the presence of sunlight), resulting in a buildup of toxic
products. These herbicides are normally root or foliar absorbed.
✔✔Photosynthesis Inhibitors Chemical Families - ✔✔Triazines (Sencor),
Phenylureas (Lorox),
Uracils (Sinbar),
Benzothiadiazoles (Basagran),
Nitriles (Buctril).
✔✔Cell Membrane Disruptors - ✔✔Destroy plant tissue by rupturing plant cell
membranes. These contact herbicides have no mobility in the plant and must be applied
post-emergence.
✔✔Cell Membrane Chemical Families - ✔✔Bipyridyliums (Gramoxone),
Diphenyl Ethers (Blazer).
✔✔Pigment Inhibitors - ✔✔prevents plants from forming chlorophyll that is essential for
photosynthesis. These soil applied herbicides translocate to plant leaves.
✔✔Pigment Inhibitors Chemical Families - ✔✔Isoxazolidinones (Command),
Pyridazinones (Solicam).
✔✔Selective Herbicides - ✔✔A herbicide that kills one type of plant but does not
seriously affect other types of plants.
✔✔Nonselective Herbicides - ✔✔Herbicides that kill/control most or all plants.
✔✔Pre-Emergence Treatment - ✔✔A treatment made prior to emergence of a crop or
weed.
✔✔Post-Emergence Treatment - ✔✔Any treatment made after emergence of a
specified crop or weed.
✔✔GPA - ✔✔5940 x nozzle output GPM/ MPH x nozzle spacing inches
✔✔Amount ai - ✔✔Amount Product x % ai
✔✔Amount Product - ✔✔Amount ai / % ai
✔✔lbs ai - ✔✔Gal Product x lb ai/gal
✔✔Gal Product - ✔✔lbs ai / lb ai per gallon
