Ques ons and answers Newest RATED A+ 2025/2026
What is the greatest hazard when applying most herbicides? - Ans Injury to nontarget plants
Name some herbicides which are very effec ve against germina ng weeds but less effec ve on
established weeds. - Ans Fron er, Lasso, and Dual
What soil condi ons reduce the ac vity of many herbicides and require increased rates for
adequate weed control? - Ans Higher levels of soil organic ma(er or clay
Two herbicides which are more ac ve on soils with a pH above 7.5 and can injure soybeans -
Ans Sencor and Lexone
Where are high pH soils most common in Iowa? - Ans Next to limestone and gravel roads
Two herbicides that are more persistent and likely to carryover residues. - Ans Atrazine and
chlorimuron
What factors can increase chances of herbicide carryover? - Ans Dry weather, high rates, late
applica on, and in the case of some herbicides, high soil pH
Can addi ve injury occur when applying Sencor/Lexone on soybeans in fields with atrazine
carryover residues? - Ans Yes
What do preemergence herbicides rely on to move the herbicide into the weed seed
germina on zone (top 1/2-1 inch) of soil? - Ans Rainfall or irriga on
, What llage tools will improve weed control when rainfall does not occur soon a8er herbicide
applica on, and weeds begin emerging? - Ans Rotary Hoe and Harrow
Name 3 herbicides which must be incorporated to prevent evapora on loss. - Ans Sultan+,
Eradicane, Eradicane Extra
Define photodecomposi on - Ans Chemical breakdown caused by exposure to light
Name two herbicides that must be incorporated to prevent photodecomposi on. - Ans Treflan,
Sonalan
Why are Basagran, Blazer, Buctril, Poast Plus, and Fusilade 2000 only applied postemergence? -
Ans They have li(le or no soil ac vity
Are Roundup and Gramoxone Extra selec ve or nonselec ve herbicides? - Ans Nonselec ve
Are Blazer, Basagran, Buctril, and Gramoxone Extra contact herbicides or translocated
herbicides? - Ans Contact herbicides
Define translocated herbicides - Ans Herbicides which move in the phloem of plants
Do translocated herbicides move up, down, or both ways in plants? - Ans Because translocated
herbicides move within the phloem, they can move both up and down a plant.
Are Roundup, 2,4-D, Fusilade 2000, Poast Plus, Clarity, and Banvil contact herbicides or
translocted herbicides? - Ans Translocated herbicides