Lowa Commercial Pesticide Applicator
Category 1A 2024/2025 Exam Questions
and Correct Answers | New Update
What is the greatest hazard when applying most herbicides? - 🧠ANSWER
✔✔Injury to nontarget plants
Name some herbicides which are very effective against germinating weeds
but less effective on established weeds. - 🧠ANSWER ✔✔Frontier, Lasso,
and Dual
What soil conditions reduce the activity of many herbicides and require
increased rates for adequate weed control? - 🧠ANSWER ✔✔Higher levels
of soil organic matter or clay
Two herbicides which are more active on soils with a pH above 7.5 and can
injure soybeans - 🧠ANSWER ✔✔Sencor and Lexone
Where are high pH soils most common in Iowa? - 🧠ANSWER ✔✔Next to
limestone and gravel roads
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY 1
STATEMENT. ALL RIGHTS RESERVED
, Two herbicides that are more persistent and likely to carryover residues. -
🧠ANSWER ✔✔Atrazine and chlorimuron
What factors can increase chances of herbicide carryover? - 🧠ANSWER
✔✔Dry weather, high rates, late application, and in the case of some
herbicides, high soil pH
Can additive injury occur when applying Sencor/Lexone on soybeans in
fields with atrazine carryover residues? - 🧠ANSWER ✔✔Yes
What do preemergence herbicides rely on to move the herbicide into the
weed seed germination zone (top 1/2-1 inch) of soil? - 🧠ANSWER
✔✔Rainfall or irrigation
What tillage tools will improve weed control when rainfall does not occur
soon after herbicide application, and weeds begin emerging? - 🧠ANSWER
✔✔Rotary Hoe and Harrow
Name 3 herbicides which must be incorporated to prevent evaporation loss.
- 🧠ANSWER ✔✔Sultan+, Eradicane, Eradicane Extra
Define photodecomposition - 🧠ANSWER ✔✔Chemical breakdown caused
by exposure to light
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY 2
STATEMENT. ALL RIGHTS RESERVED
Category 1A 2024/2025 Exam Questions
and Correct Answers | New Update
What is the greatest hazard when applying most herbicides? - 🧠ANSWER
✔✔Injury to nontarget plants
Name some herbicides which are very effective against germinating weeds
but less effective on established weeds. - 🧠ANSWER ✔✔Frontier, Lasso,
and Dual
What soil conditions reduce the activity of many herbicides and require
increased rates for adequate weed control? - 🧠ANSWER ✔✔Higher levels
of soil organic matter or clay
Two herbicides which are more active on soils with a pH above 7.5 and can
injure soybeans - 🧠ANSWER ✔✔Sencor and Lexone
Where are high pH soils most common in Iowa? - 🧠ANSWER ✔✔Next to
limestone and gravel roads
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY 1
STATEMENT. ALL RIGHTS RESERVED
, Two herbicides that are more persistent and likely to carryover residues. -
🧠ANSWER ✔✔Atrazine and chlorimuron
What factors can increase chances of herbicide carryover? - 🧠ANSWER
✔✔Dry weather, high rates, late application, and in the case of some
herbicides, high soil pH
Can additive injury occur when applying Sencor/Lexone on soybeans in
fields with atrazine carryover residues? - 🧠ANSWER ✔✔Yes
What do preemergence herbicides rely on to move the herbicide into the
weed seed germination zone (top 1/2-1 inch) of soil? - 🧠ANSWER
✔✔Rainfall or irrigation
What tillage tools will improve weed control when rainfall does not occur
soon after herbicide application, and weeds begin emerging? - 🧠ANSWER
✔✔Rotary Hoe and Harrow
Name 3 herbicides which must be incorporated to prevent evaporation loss.
- 🧠ANSWER ✔✔Sultan+, Eradicane, Eradicane Extra
Define photodecomposition - 🧠ANSWER ✔✔Chemical breakdown caused
by exposure to light
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY 2
STATEMENT. ALL RIGHTS RESERVED
