IOWA COMMERCIAL PESTICIDE APPLICATOR CATEGORY 1A EXAM | QUESTIONS & 100% CORRECT ANSWERS (VERIFIED) | LATEST UPDATE | GRADEA+

IOWA COMMERCIAL PESTICIDE APPLICATOR CATEGORY 1A EXAM | QUESTIONS & 100% CORRECT ANSWERS (VERIFIED) | LATEST UPDATE | GRADEA+ What is the greatest hazard when applying most herbicides? Correct Answer: Injury to nontarget plants Name some herbicides which are very effective against germinating weeds but less effective on established weeds. Correct Answer: Frontier, Lasso, and Dual What soil conditions reduce the activity of many herbicides and require increased rates for adequate weed control? Correct 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 Correct Answer: Sencor and Lexone Where are high pH soils most common in Iowa? Correct Answer: Next to limestone and gravel roads Two herbicides that are more persistent and likely to carryover residues. Correct Answer: Atrazine and chlorimuron What factors can increase chances of herbicide carryover? Correct 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? Correct 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? Correct Answer: Rainfall or irrigation