Herbicides and Pesticides: Definitions and
Applications Verified Quizzes + Top-Scoring
Assignments | A+ Guaranteed
Weed - plant growing where it is not desired
Herbicide - any chemical or cultured biological organism used to destroy, prevent,
suppress, or control plants
Pesticide - a chemical used to control or destroy a pest
Control - management or manipulation of a pest, so it is no longer a threat or concern
Top four chemical companies - Sygenta, Bayer, BASF, Corteva
Weed impacts - lower crop and animal yields, less efficient land use, allelopathy, animal
toxicity, human allergies, crop quality, water management, recreation, fire hazard, obstruction
of visibility
Liquid formulations - solution, emulsifiable concentrate, flowable
Solution (SL or S) - ex- roundup/rodeo (glyphosate), advantages- low agitation,
disadvantages- none
Emulsifiable concentrate (EC or E) - ex- Garlon (Triclopyr), Vanquish(Dicamba), Trimec
plus(MSMA), advantages- high % ai, nonabrasive, low agitation. disadvantages- readily adsorbed
by skin, easy to over dose
Flowable (FL, F, or L) - ex- Aatrex 4L (Atrazine), advantages- easy to handle, less abrasive
than dry formulations. disadvantages- moderate agitation
Dry formulations - Granule, wettable powder, water dispersible granule or dry flowable,
soluble powder
Granule (G) - ex- Pendulum (Pendumethalin), XL 2G (Benefin + Oryzalin), advantages-
ready to use, persistent. Disadvantages- expensive, needs moisture to activate
Wettable powder (WP) - ex- Hyvar X(Bromacil), Karmex 80W (Diuron). Advantages- low
cost, low skin and eye absorption. Disadvantages- easily inhaled, constant agitation, abrasive
, Water-dispersible granule or dry flowable - ex- Outst 75 WDG (Sulfometuron), Aatrex
90DF (Atrazine). advantages- low cost, easy to handle. Disadvantages- constant agitation,
abrasive
Soluble powder (SP) - ex- Velpar VLW (Hexazione). advantages- low costs. Disadvantages-
easily inhaled
Adjuvants - any material which is added to a herbicide mixture to enhance or modify the
performance of the herbicide
Surfactants - help increase coverage of treated area
Crop oils - increases coverage and penetration into pest
Compatibility agents - allows for pesticides to combine effectively
Drift control additives - reduce fine spray particles
Mixing order - Dry flowable, wettable powder, soluble powder, flowable,
microencapsulated, emulsifiable concentrate, soluble liquid, adjuvant
Antagonism - less effect than expected, one product reduces the activity of another
Synergism - more effect than expected, one product aids other product
Colby's method - E = A + B - ((A*B)/100)
GPA for aerial applications - 3 to 10
GPA for ground applications - 10 to 20
GPA for wet to run-off (turf, forestry) - 20 to 100
When to use 100 mesh screen - less than or equal to 0.15 GPM at 40PSI
When to use 50 mesh screen - 0.2 GPM and up at 40 PSI
Nozzle types (letters before nozzle size) - TT - turbo, AI - air induction, TTI - turbo air
induction, XR - extended range, DG - drift guard. droplet size
Nozzle materials (letters after nozzle size) - VS- visiflow stainless steel, VP - visiflow
polymer, VH - Visiflow hardened stainless steel, SS- stainless steel
Spray tip material (best to worst) - Ceramic, hardened stainless steel, stainless steel,
polymer, brass
Applications Verified Quizzes + Top-Scoring
Assignments | A+ Guaranteed
Weed - plant growing where it is not desired
Herbicide - any chemical or cultured biological organism used to destroy, prevent,
suppress, or control plants
Pesticide - a chemical used to control or destroy a pest
Control - management or manipulation of a pest, so it is no longer a threat or concern
Top four chemical companies - Sygenta, Bayer, BASF, Corteva
Weed impacts - lower crop and animal yields, less efficient land use, allelopathy, animal
toxicity, human allergies, crop quality, water management, recreation, fire hazard, obstruction
of visibility
Liquid formulations - solution, emulsifiable concentrate, flowable
Solution (SL or S) - ex- roundup/rodeo (glyphosate), advantages- low agitation,
disadvantages- none
Emulsifiable concentrate (EC or E) - ex- Garlon (Triclopyr), Vanquish(Dicamba), Trimec
plus(MSMA), advantages- high % ai, nonabrasive, low agitation. disadvantages- readily adsorbed
by skin, easy to over dose
Flowable (FL, F, or L) - ex- Aatrex 4L (Atrazine), advantages- easy to handle, less abrasive
than dry formulations. disadvantages- moderate agitation
Dry formulations - Granule, wettable powder, water dispersible granule or dry flowable,
soluble powder
Granule (G) - ex- Pendulum (Pendumethalin), XL 2G (Benefin + Oryzalin), advantages-
ready to use, persistent. Disadvantages- expensive, needs moisture to activate
Wettable powder (WP) - ex- Hyvar X(Bromacil), Karmex 80W (Diuron). Advantages- low
cost, low skin and eye absorption. Disadvantages- easily inhaled, constant agitation, abrasive
, Water-dispersible granule or dry flowable - ex- Outst 75 WDG (Sulfometuron), Aatrex
90DF (Atrazine). advantages- low cost, easy to handle. Disadvantages- constant agitation,
abrasive
Soluble powder (SP) - ex- Velpar VLW (Hexazione). advantages- low costs. Disadvantages-
easily inhaled
Adjuvants - any material which is added to a herbicide mixture to enhance or modify the
performance of the herbicide
Surfactants - help increase coverage of treated area
Crop oils - increases coverage and penetration into pest
Compatibility agents - allows for pesticides to combine effectively
Drift control additives - reduce fine spray particles
Mixing order - Dry flowable, wettable powder, soluble powder, flowable,
microencapsulated, emulsifiable concentrate, soluble liquid, adjuvant
Antagonism - less effect than expected, one product reduces the activity of another
Synergism - more effect than expected, one product aids other product
Colby's method - E = A + B - ((A*B)/100)
GPA for aerial applications - 3 to 10
GPA for ground applications - 10 to 20
GPA for wet to run-off (turf, forestry) - 20 to 100
When to use 100 mesh screen - less than or equal to 0.15 GPM at 40PSI
When to use 50 mesh screen - 0.2 GPM and up at 40 PSI
Nozzle types (letters before nozzle size) - TT - turbo, AI - air induction, TTI - turbo air
induction, XR - extended range, DG - drift guard. droplet size
Nozzle materials (letters after nozzle size) - VS- visiflow stainless steel, VP - visiflow
polymer, VH - Visiflow hardened stainless steel, SS- stainless steel
Spray tip material (best to worst) - Ceramic, hardened stainless steel, stainless steel,
polymer, brass
