Nevada Urban & Structural Pest Control Applicator —
Category C6 Weeds Examination Complete Questions
And Detailed Solutions Latest Update This Year
Q1: Nevada Category C6 Weeds definition urban and structural?
A. Only aquatic weeds lakes
B. Control of weeds in non-agricultural areas - industrial sites, rights-of-way, buildings, sidewalks, driveways, parking lots, ornamental
beds, bare ground sterilants - ground equipment - not agricultural crops
C. Control of weeds in corn wheat alfalfa field crops agricultural
D. Only forestry trees
Answer & ULTRA-Detailed Rationale:
B. Control of weeds in non-agricultural areas - industrial sites, rights-of-way, buildings, sidewalks, driveways, parking lots,
ornamental beds, bare ground sterilants - ground equipment - not agricultural crops
CONCEPT: Scope C6 urban structural weeds. CORRECT - A: C6 Weeds Urban & Structural per Nevada Dept Agriculture NDA:
control of weeds in non-agricultural areas: industrial sites, rights-of-way, buildings, sidewalks, driveways, parking lots,
ornamental beds, cracks, bare ground, sterilants for total vegetation control. Ground equipment backpack, boom, hand sprayer.
Not agricultural crops (that's B2). Requires knowledge non-selective selective herbicides, bare ground sterilants, ornamentals tolerance.
WHY B WRONG: Corn wheat alfalfa field crops is Category B2 Agricultural Weeds - not urban structural C6 - different label sites,
different regulations, different buffer requirements. C6 is non-crop. WHY C WRONG: Aquatic weeds lakes is Category C5 Aquatic or
separate aquatic category - not C6 - C6 is terrestrial non-crop. WHY D WRONG: Forestry trees is forestry category - not C6 - C6 is
urban structural industrial right-of-way. EXAM TIP: C6 = industrial sites, rights-of-way, parking lots, sidewalks, bare ground, ornamentals
- non-crop - memorize non-crop.
Q2: Non-selective vs selective herbicide in C6 ornamental beds?
A. Non-selective kills all vegetation contacted e.g., glyphosate - use for bare ground total vegetation control - selective kills some
plants not others e.g., 2,4-D broadleaf in turfgrass, sethoxydim grass in ornamentals
B. Selective kills all
C. Non-selective kills only broadleaf
D. Same non-selective and selective same
Answer & ULTRA-Detailed Rationale:
A. Non-selective kills all vegetation contacted e.g., glyphosate - use for bare ground total vegetation control - selective kills
some plants not others e.g., 2,4-D broadleaf in turfgrass, sethoxydim grass in ornamentals
CONCEPT: Selectivity critical for C6 to avoid damage to ornamentals. CORRECT - A: Non-selective kills all vegetation contacted
e.g., glyphosate, glufosinate, diquat - use for bare ground total vegetation control parking lots, cracks, industrial sites - must
avoid drift to desirable ornamentals. Selective kills target weeds not desired plants e.g., 2,4-D kills broadleaf weeds in turfgrass
(grass tolerates), sethoxydim fluazifop kills grasses in ornamental beds (broadleaf ornamentals tolerate), triclopyr broadleaf in
turf. WHY B WRONG: Not same - selectivity is core concept - confusing causes ornamental damage - liability - exam tests you know
difference. WHY C WRONG: Selective kills some not all - definition reversed - selective spares desired plants. WHY D WRONG:
Non-selective kills all not only broadleaf - non-selective broad-spectrum. EXAM TIP: Ornamental beds = use selective grass killer to kill
grass weeds in broadleaf ornamentals - or preemergence - non-selective would kill ornamentals.
Page 1 | NV C6 WEEDS URBAN STRUCTURAL - ULTRA - BIG TITLE - 200Q
,Q3: Preemergence vs postemergence for C6 weed control?
A. Preemergence applied before weed emergence prevents germination soil active needs incorporation or water - e.g.,
pendimethalin, prodiamine - postemergence applied after weed emergence foliar active e.g., glyphosate 2,4-D - many C6 programs
combine both
B. Same timing
C. Postemergence before weeds emerged
D. Preemergence after weeds emerged
Answer & ULTRA-Detailed Rationale:
A. Preemergence applied before weed emergence prevents germination soil active needs incorporation or water - e.g.,
pendimethalin, prodiamine - postemergence applied after weed emergence foliar active e.g., glyphosate 2,4-D - many C6
programs combine both
CONCEPT: Timing. CORRECT - A: Preemergence before emergence soil active - prevents seed germination - requires rain or
irrigation incorporation - e.g., pendimethalin, prodiamine, oryzalin, isoxaben - used in ornamental beds, rights-of-way to
prevent annual weeds. Postemergence after emergence foliar active - e.g., glyphosate non-selective, 2,4-D broadleaf, MSMA -
must contact weed foliage. Many C6 bare ground programs use pre + post tank mix for residual plus knockdown. WHY B WRONG:
Timing differs - pre before, post after - not same - label specifies timing. WHY C WRONG: Preemergence after weeds emerged too late -
pre won't kill emerged weeds - would fail. WHY D WRONG: Postemergence before weeds emerged no foliage to contact - would fail -
post needs emerged weed. EXAM TIP: Pre = before - needs water activation - post = after - needs foliar contact - many C6 questions
ask which to use for emerged weeds vs prevention.
Q4: Bare ground sterilant herbicide - what is it and use restrictions C6?
A. Short residual only few days
B. Only for agricultural crops
C. Bare ground sterilant provides total vegetation control for extended period months to year - e.g., bromacil, diuron, imazapyr,
sulfometuron - use on industrial sites, rights-of-way, under asphalt - high persistence - must avoid runoff to desirable plants, water -
buffer zones
D. No restrictions can use anywhere near ornamentals
Answer & ULTRA-Detailed Rationale:
C. Bare ground sterilant provides total vegetation control for extended period months to year - e.g., bromacil, diuron, imazapyr,
sulfometuron - use on industrial sites, rights-of-way, under asphalt - high persistence - must avoid runoff to desirable plants,
water - buffer zones
CONCEPT: Bare ground sterilants - high risk high persistence. CORRECT - A: Bare ground sterilant = total vegetation control long
residual months to >year - e.g., bromacil, diuron, imazapyr, sulfometuron, tebuthiuron - use industrial sites, substations,
rights-of-way, under asphalt, parking lots. High persistence, mobile in soil, potential runoff to non-target ornamentals, trees,
water - must have buffer zones, avoid slopes leading to ornamentals, avoid near desirable tree root zones (drip line), avoid
water. Label specifies max rate, frequency. WHY B WRONG: Short residual few days is contact herbicide like diquat - not sterilant -
sterilant is long residual - confusing. WHY C WRONG: No restrictions false - sterilants have major restrictions due to mobility and
persistence - must not use near ornamentals or water - many lawsuits from sterilant runoff killing trees - exam tests restrictions. WHY D
WRONG: Only agricultural false - sterilants are non-crop industrial right-of-way - not agricultural - agricultural uses different herbicides.
EXAM TIP: Sterilants = long residual - high risk - buffer zones - never use near desirable tree root zone - tree drip line plus 2x.
Page 2 | NV C6 WEEDS URBAN STRUCTURAL - ULTRA - BIG TITLE - 200Q
,Q5: Herbicide drift to ornamentals - how to minimize in C6?
A. Spray during inversion best
B. Use low drift nozzles air induction, larger droplet coarse, low boom height 18-24 inches, wind 3-10 mph avoid inversion, avoid high
temperature >85F for ester formulations, buffer zones downwind ornamentals
C. Use high boom fine droplets high wind
D. No drift control needed
Answer & ULTRA-Detailed Rationale:
B. Use low drift nozzles air induction, larger droplet coarse, low boom height 18-24 inches, wind 3-10 mph avoid inversion,
avoid high temperature >85F for ester formulations, buffer zones downwind ornamentals
CONCEPT: Drift minimization urban areas with sensitive ornamentals. CORRECT - A: Drift minimization: low drift nozzles air
induction AI produce coarse droplets, larger droplet ASABE coarse very coarse, low boom 18-24 inch, wind 3-10 mph ideal
avoid less than 3 mph inversion and greater than 10 mph drift, avoid high temp above 85F especially ester formulations 2,4-D
dicamba volatile, buffer zones downwind ornamentals, use amine not ester less volatile, drift retardant adjuvant if label allows.
WHY B WRONG: High boom fine droplets high wind increases drift - opposite of best practice - would cause ornamental damage -
violation. WHY C WRONG: Drift control needed especially C6 urban with ornamentals nearby - many damage claims - must minimize.
WHY D WRONG: Spray during inversion worst - inversion traps small droplets suspended long distance drift - dust hangs fog dew
indicators - do not spray. EXAM TIP: Ornamentals highly sensitive to auxin herbicides 2,4-D dicamba - use amine less volatile than
ester.
Q6: Weed life cycle - annual summer winter biennial perennial for C6 timing?
A. Annual completes 1 year summer annual germinates spring e.g., crabgrass pigweed - winter annual germinates fall e.g., annual
bluegrass cheatgrass - biennial 2 years rosette first year - perennial lives more than 2 years reproduces seeds and vegetative e.g.,
bermudagrass field bindweed
B. No life cycles
C. Perennial lives 1 year only
D. All weeds annual only
Answer & ULTRA-Detailed Rationale:
A. Annual completes 1 year summer annual germinates spring e.g., crabgrass pigweed - winter annual germinates fall e.g.,
annual bluegrass cheatgrass - biennial 2 years rosette first year - perennial lives more than 2 years reproduces seeds and
vegetative e.g., bermudagrass field bindweed
CONCEPT: Life cycle affects timing. CORRECT - A: Summer annual germinates spring summer - crabgrass pigweed purslane -
control pre spring or early post small. Winter annual germinates fall - annual bluegrass cheatgrass henbit - control pre fall or early
spring rosette. Biennial 2 years rosette year1 flower year2 e.g., mullein musk thistle. Perennial greater than 2 years reproduces
seeds vegetative rhizomes stolons e.g., bermudagrass field bindweed dandelion - harder need systemic fall timing repeated.
WHY B WRONG: Not all annual - biennial perennial exist - control differs. WHY C WRONG: Perennial lives greater than 2 years not 1 -
1 year is annual. WHY D WRONG: Life cycles exist and critical for timing. EXAM TIP: Perennial harder - systemic herbicide fall when
nutrients moving to roots.
Page 3 | NV C6 WEEDS URBAN STRUCTURAL - ULTRA - BIG TITLE - 200Q
, Q7: Ornamental tolerance - why some ornamentals tolerant to certain herbicides?
A. Tolerance due to morphology, physiology, metabolism - e.g., waxy leaves, deep roots, ability to metabolize herbicide - selective
herbicide exploits difference - must read label for tolerant ornamentals list
B. All ornamentals tolerant to all herbicides
C. No ornamentals tolerant
D. Tolerance random no basis
Answer & ULTRA-Detailed Rationale:
A. Tolerance due to morphology, physiology, metabolism - e.g., waxy leaves, deep roots, ability to metabolize herbicide -
selective herbicide exploits difference - must read label for tolerant ornamentals list
CONCEPT: Selectivity mechanism. CORRECT - A: Tolerance due to morphology waxy cuticle, hairy leaves, physiology deep roots
vs shallow, metabolism ability to detoxify herbicide via cytochrome P450 - selective herbicide exploits difference between
weed and desirable - must read label for list of tolerant ornamentals - if ornamental not on label, do not use - test on small area. WHY
B WRONG: All ornamentals tolerant to all herbicides false - many herbicides kill ornamentals - non-selective glyphosate kills all. WHY C
WRONG: No ornamentals tolerant false - many ornamentals tolerant to specific herbicides - e.g., many broadleaf ornamentals tolerant to
oryzalin preemergence. WHY D WRONG: Tolerance not random - has physiological basis - not random. EXAM TIP: Always read label
for tolerant ornamentals - if not listed, don't use or test - liability.
Q8: Spray water pH and hard water - effect on herbicide C6?
A. Hard water improves glyphosate
B. Alkaline pH best for weak acid herbicides
C. Alkaline water pH greater than 7 causes alkaline hydrolysis breakdown of some herbicides reduces efficacy - weak acid herbicides
glyphosate 2,4-D dicamba more effective acidic pH 5.5-6.5 - hard water Ca Mg Fe antagonizes glyphosate - use AMS ammonium
sulfate 8.5-17 lb per 100 gal
D. pH no effect
Answer & ULTRA-Detailed Rationale:
C. Alkaline water pH greater than 7 causes alkaline hydrolysis breakdown of some herbicides reduces efficacy - weak acid
herbicides glyphosate 2,4-D dicamba more effective acidic pH 5.5-6.5 - hard water Ca Mg Fe antagonizes glyphosate - use AMS
ammonium sulfate 8.5-17 lb per 100 gal
CONCEPT: Water quality. CORRECT - A: Alkaline water pH greater than 7 causes alkaline hydrolysis breakdown
organophosphates carbamates some herbicides reduces half-life efficacy - ideal pH 5.5-6.5 slightly acidic for weak acid
herbicides glyphosate 2,4-D dicamba - hard water cations Ca Mg Fe antagonize glyphosate bind reduces absorption - use AMS
ammonium sulfate 8.5-17 lb per 100 gal to overcome. WHY B WRONG: pH has effect - alkaline hydrolysis documented. WHY C
WRONG: Hard water antagonizes glyphosate reduces efficacy - not improves - many failures due to hard water. WHY D WRONG:
Alkaline pH worst for weak acid herbicides - acidic pH best - reverse. EXAM TIP: Weak acid herbicides acidic pH better - hard water
hurts glyphosate - AMS helps.
Page 4 | NV C6 WEEDS URBAN STRUCTURAL - ULTRA - BIG TITLE - 200Q
Category C6 Weeds Examination Complete Questions
And Detailed Solutions Latest Update This Year
Q1: Nevada Category C6 Weeds definition urban and structural?
A. Only aquatic weeds lakes
B. Control of weeds in non-agricultural areas - industrial sites, rights-of-way, buildings, sidewalks, driveways, parking lots, ornamental
beds, bare ground sterilants - ground equipment - not agricultural crops
C. Control of weeds in corn wheat alfalfa field crops agricultural
D. Only forestry trees
Answer & ULTRA-Detailed Rationale:
B. Control of weeds in non-agricultural areas - industrial sites, rights-of-way, buildings, sidewalks, driveways, parking lots,
ornamental beds, bare ground sterilants - ground equipment - not agricultural crops
CONCEPT: Scope C6 urban structural weeds. CORRECT - A: C6 Weeds Urban & Structural per Nevada Dept Agriculture NDA:
control of weeds in non-agricultural areas: industrial sites, rights-of-way, buildings, sidewalks, driveways, parking lots,
ornamental beds, cracks, bare ground, sterilants for total vegetation control. Ground equipment backpack, boom, hand sprayer.
Not agricultural crops (that's B2). Requires knowledge non-selective selective herbicides, bare ground sterilants, ornamentals tolerance.
WHY B WRONG: Corn wheat alfalfa field crops is Category B2 Agricultural Weeds - not urban structural C6 - different label sites,
different regulations, different buffer requirements. C6 is non-crop. WHY C WRONG: Aquatic weeds lakes is Category C5 Aquatic or
separate aquatic category - not C6 - C6 is terrestrial non-crop. WHY D WRONG: Forestry trees is forestry category - not C6 - C6 is
urban structural industrial right-of-way. EXAM TIP: C6 = industrial sites, rights-of-way, parking lots, sidewalks, bare ground, ornamentals
- non-crop - memorize non-crop.
Q2: Non-selective vs selective herbicide in C6 ornamental beds?
A. Non-selective kills all vegetation contacted e.g., glyphosate - use for bare ground total vegetation control - selective kills some
plants not others e.g., 2,4-D broadleaf in turfgrass, sethoxydim grass in ornamentals
B. Selective kills all
C. Non-selective kills only broadleaf
D. Same non-selective and selective same
Answer & ULTRA-Detailed Rationale:
A. Non-selective kills all vegetation contacted e.g., glyphosate - use for bare ground total vegetation control - selective kills
some plants not others e.g., 2,4-D broadleaf in turfgrass, sethoxydim grass in ornamentals
CONCEPT: Selectivity critical for C6 to avoid damage to ornamentals. CORRECT - A: Non-selective kills all vegetation contacted
e.g., glyphosate, glufosinate, diquat - use for bare ground total vegetation control parking lots, cracks, industrial sites - must
avoid drift to desirable ornamentals. Selective kills target weeds not desired plants e.g., 2,4-D kills broadleaf weeds in turfgrass
(grass tolerates), sethoxydim fluazifop kills grasses in ornamental beds (broadleaf ornamentals tolerate), triclopyr broadleaf in
turf. WHY B WRONG: Not same - selectivity is core concept - confusing causes ornamental damage - liability - exam tests you know
difference. WHY C WRONG: Selective kills some not all - definition reversed - selective spares desired plants. WHY D WRONG:
Non-selective kills all not only broadleaf - non-selective broad-spectrum. EXAM TIP: Ornamental beds = use selective grass killer to kill
grass weeds in broadleaf ornamentals - or preemergence - non-selective would kill ornamentals.
Page 1 | NV C6 WEEDS URBAN STRUCTURAL - ULTRA - BIG TITLE - 200Q
,Q3: Preemergence vs postemergence for C6 weed control?
A. Preemergence applied before weed emergence prevents germination soil active needs incorporation or water - e.g.,
pendimethalin, prodiamine - postemergence applied after weed emergence foliar active e.g., glyphosate 2,4-D - many C6 programs
combine both
B. Same timing
C. Postemergence before weeds emerged
D. Preemergence after weeds emerged
Answer & ULTRA-Detailed Rationale:
A. Preemergence applied before weed emergence prevents germination soil active needs incorporation or water - e.g.,
pendimethalin, prodiamine - postemergence applied after weed emergence foliar active e.g., glyphosate 2,4-D - many C6
programs combine both
CONCEPT: Timing. CORRECT - A: Preemergence before emergence soil active - prevents seed germination - requires rain or
irrigation incorporation - e.g., pendimethalin, prodiamine, oryzalin, isoxaben - used in ornamental beds, rights-of-way to
prevent annual weeds. Postemergence after emergence foliar active - e.g., glyphosate non-selective, 2,4-D broadleaf, MSMA -
must contact weed foliage. Many C6 bare ground programs use pre + post tank mix for residual plus knockdown. WHY B WRONG:
Timing differs - pre before, post after - not same - label specifies timing. WHY C WRONG: Preemergence after weeds emerged too late -
pre won't kill emerged weeds - would fail. WHY D WRONG: Postemergence before weeds emerged no foliage to contact - would fail -
post needs emerged weed. EXAM TIP: Pre = before - needs water activation - post = after - needs foliar contact - many C6 questions
ask which to use for emerged weeds vs prevention.
Q4: Bare ground sterilant herbicide - what is it and use restrictions C6?
A. Short residual only few days
B. Only for agricultural crops
C. Bare ground sterilant provides total vegetation control for extended period months to year - e.g., bromacil, diuron, imazapyr,
sulfometuron - use on industrial sites, rights-of-way, under asphalt - high persistence - must avoid runoff to desirable plants, water -
buffer zones
D. No restrictions can use anywhere near ornamentals
Answer & ULTRA-Detailed Rationale:
C. Bare ground sterilant provides total vegetation control for extended period months to year - e.g., bromacil, diuron, imazapyr,
sulfometuron - use on industrial sites, rights-of-way, under asphalt - high persistence - must avoid runoff to desirable plants,
water - buffer zones
CONCEPT: Bare ground sterilants - high risk high persistence. CORRECT - A: Bare ground sterilant = total vegetation control long
residual months to >year - e.g., bromacil, diuron, imazapyr, sulfometuron, tebuthiuron - use industrial sites, substations,
rights-of-way, under asphalt, parking lots. High persistence, mobile in soil, potential runoff to non-target ornamentals, trees,
water - must have buffer zones, avoid slopes leading to ornamentals, avoid near desirable tree root zones (drip line), avoid
water. Label specifies max rate, frequency. WHY B WRONG: Short residual few days is contact herbicide like diquat - not sterilant -
sterilant is long residual - confusing. WHY C WRONG: No restrictions false - sterilants have major restrictions due to mobility and
persistence - must not use near ornamentals or water - many lawsuits from sterilant runoff killing trees - exam tests restrictions. WHY D
WRONG: Only agricultural false - sterilants are non-crop industrial right-of-way - not agricultural - agricultural uses different herbicides.
EXAM TIP: Sterilants = long residual - high risk - buffer zones - never use near desirable tree root zone - tree drip line plus 2x.
Page 2 | NV C6 WEEDS URBAN STRUCTURAL - ULTRA - BIG TITLE - 200Q
,Q5: Herbicide drift to ornamentals - how to minimize in C6?
A. Spray during inversion best
B. Use low drift nozzles air induction, larger droplet coarse, low boom height 18-24 inches, wind 3-10 mph avoid inversion, avoid high
temperature >85F for ester formulations, buffer zones downwind ornamentals
C. Use high boom fine droplets high wind
D. No drift control needed
Answer & ULTRA-Detailed Rationale:
B. Use low drift nozzles air induction, larger droplet coarse, low boom height 18-24 inches, wind 3-10 mph avoid inversion,
avoid high temperature >85F for ester formulations, buffer zones downwind ornamentals
CONCEPT: Drift minimization urban areas with sensitive ornamentals. CORRECT - A: Drift minimization: low drift nozzles air
induction AI produce coarse droplets, larger droplet ASABE coarse very coarse, low boom 18-24 inch, wind 3-10 mph ideal
avoid less than 3 mph inversion and greater than 10 mph drift, avoid high temp above 85F especially ester formulations 2,4-D
dicamba volatile, buffer zones downwind ornamentals, use amine not ester less volatile, drift retardant adjuvant if label allows.
WHY B WRONG: High boom fine droplets high wind increases drift - opposite of best practice - would cause ornamental damage -
violation. WHY C WRONG: Drift control needed especially C6 urban with ornamentals nearby - many damage claims - must minimize.
WHY D WRONG: Spray during inversion worst - inversion traps small droplets suspended long distance drift - dust hangs fog dew
indicators - do not spray. EXAM TIP: Ornamentals highly sensitive to auxin herbicides 2,4-D dicamba - use amine less volatile than
ester.
Q6: Weed life cycle - annual summer winter biennial perennial for C6 timing?
A. Annual completes 1 year summer annual germinates spring e.g., crabgrass pigweed - winter annual germinates fall e.g., annual
bluegrass cheatgrass - biennial 2 years rosette first year - perennial lives more than 2 years reproduces seeds and vegetative e.g.,
bermudagrass field bindweed
B. No life cycles
C. Perennial lives 1 year only
D. All weeds annual only
Answer & ULTRA-Detailed Rationale:
A. Annual completes 1 year summer annual germinates spring e.g., crabgrass pigweed - winter annual germinates fall e.g.,
annual bluegrass cheatgrass - biennial 2 years rosette first year - perennial lives more than 2 years reproduces seeds and
vegetative e.g., bermudagrass field bindweed
CONCEPT: Life cycle affects timing. CORRECT - A: Summer annual germinates spring summer - crabgrass pigweed purslane -
control pre spring or early post small. Winter annual germinates fall - annual bluegrass cheatgrass henbit - control pre fall or early
spring rosette. Biennial 2 years rosette year1 flower year2 e.g., mullein musk thistle. Perennial greater than 2 years reproduces
seeds vegetative rhizomes stolons e.g., bermudagrass field bindweed dandelion - harder need systemic fall timing repeated.
WHY B WRONG: Not all annual - biennial perennial exist - control differs. WHY C WRONG: Perennial lives greater than 2 years not 1 -
1 year is annual. WHY D WRONG: Life cycles exist and critical for timing. EXAM TIP: Perennial harder - systemic herbicide fall when
nutrients moving to roots.
Page 3 | NV C6 WEEDS URBAN STRUCTURAL - ULTRA - BIG TITLE - 200Q
, Q7: Ornamental tolerance - why some ornamentals tolerant to certain herbicides?
A. Tolerance due to morphology, physiology, metabolism - e.g., waxy leaves, deep roots, ability to metabolize herbicide - selective
herbicide exploits difference - must read label for tolerant ornamentals list
B. All ornamentals tolerant to all herbicides
C. No ornamentals tolerant
D. Tolerance random no basis
Answer & ULTRA-Detailed Rationale:
A. Tolerance due to morphology, physiology, metabolism - e.g., waxy leaves, deep roots, ability to metabolize herbicide -
selective herbicide exploits difference - must read label for tolerant ornamentals list
CONCEPT: Selectivity mechanism. CORRECT - A: Tolerance due to morphology waxy cuticle, hairy leaves, physiology deep roots
vs shallow, metabolism ability to detoxify herbicide via cytochrome P450 - selective herbicide exploits difference between
weed and desirable - must read label for list of tolerant ornamentals - if ornamental not on label, do not use - test on small area. WHY
B WRONG: All ornamentals tolerant to all herbicides false - many herbicides kill ornamentals - non-selective glyphosate kills all. WHY C
WRONG: No ornamentals tolerant false - many ornamentals tolerant to specific herbicides - e.g., many broadleaf ornamentals tolerant to
oryzalin preemergence. WHY D WRONG: Tolerance not random - has physiological basis - not random. EXAM TIP: Always read label
for tolerant ornamentals - if not listed, don't use or test - liability.
Q8: Spray water pH and hard water - effect on herbicide C6?
A. Hard water improves glyphosate
B. Alkaline pH best for weak acid herbicides
C. Alkaline water pH greater than 7 causes alkaline hydrolysis breakdown of some herbicides reduces efficacy - weak acid herbicides
glyphosate 2,4-D dicamba more effective acidic pH 5.5-6.5 - hard water Ca Mg Fe antagonizes glyphosate - use AMS ammonium
sulfate 8.5-17 lb per 100 gal
D. pH no effect
Answer & ULTRA-Detailed Rationale:
C. Alkaline water pH greater than 7 causes alkaline hydrolysis breakdown of some herbicides reduces efficacy - weak acid
herbicides glyphosate 2,4-D dicamba more effective acidic pH 5.5-6.5 - hard water Ca Mg Fe antagonizes glyphosate - use AMS
ammonium sulfate 8.5-17 lb per 100 gal
CONCEPT: Water quality. CORRECT - A: Alkaline water pH greater than 7 causes alkaline hydrolysis breakdown
organophosphates carbamates some herbicides reduces half-life efficacy - ideal pH 5.5-6.5 slightly acidic for weak acid
herbicides glyphosate 2,4-D dicamba - hard water cations Ca Mg Fe antagonize glyphosate bind reduces absorption - use AMS
ammonium sulfate 8.5-17 lb per 100 gal to overcome. WHY B WRONG: pH has effect - alkaline hydrolysis documented. WHY C
WRONG: Hard water antagonizes glyphosate reduces efficacy - not improves - many failures due to hard water. WHY D WRONG:
Alkaline pH worst for weak acid herbicides - acidic pH best - reverse. EXAM TIP: Weak acid herbicides acidic pH better - hard water
hurts glyphosate - AMS helps.
Page 4 | NV C6 WEEDS URBAN STRUCTURAL - ULTRA - BIG TITLE - 200Q
