38. Which of the following is not an important consideration in planning a successful aquatic herbicide program?
A. Proper identification of the weed(s)
B. Uses of the water
C. Watertemperature
D. Clarity of the water
E. Toxicity to fish
39. Which of the following is not a true statement concerning copper sulfate?
A. Copper sulfate is strictly used for filamentous algae control
B. Copper sulfate is a preemergent herbicide
C. Copper sulfate is greatly affected by carbonate alkalinity of the water
D. Copper Sulfate has a short period of phytotoxicity
E. Copper sulfate has no restrictions on the use of the water
40. Which of the following is not true about copper sulfate?
A. It is toxic to fish at spawning
B. It is extremely corrosive to metals
C. It works best when the carbonate alkalinity of the water is high
D. The normal rate is 1 part per million or 2.7 pounds per acre-foot of
water
41. Which of the following is not an advantage of using copper chelates like Cutrine-Plus over copper sulfate?
A. They provides longer-lasting results
B. They are less toxic to fish
C. They work better in alkaline water
D. They are less expensive
42. Fish are extremely sensitive to the amine salt of endothall.
A. True
B. False
43. Potassium salt of endothall is available in liquid and granule formulation.
A. True
B. False
44. Diquat is a contact herbicide and can be applied in both clear and muddy waters.
A. True
B. False
45. Dichlobenil (Casoron) is a preemergent, granular, aquatic herbicide.
A. True
B. False
46. 2,4-D is as effective on underwater plants as it is on terrestrial plants.
A. True
B. False
47. Which of the following is not true about dalapon?
A. It provides long-term control of cattails and rushes
B. Cattails and rushes should be treated after they form flowering heads
C. Surfactants should be added to dalapon
D. Thorough coverage of the plants is required
48. Which of the following is not true about glyphosate (Pondmaster/Rodeo)?
A. Glyphosate moves systemically through the plant
B. Works best in full sunlight
C. Needs six hours before rainfall to work effectively
D. It works best if applied late in season but before leaf color change
E. It has a 7 day restriction for the use of water for swimming and fishing
49. Fluridone (Sonar) is a:
A. Systemic herbicide that inhibits a plant's ability to make food
B. Contact herbicide that controls emergent weeds
C. Systemic herbicide that works very quickly
D. Preemergent herbicide that works very quickly
50. Dosage recommendations are usually given in parts per million. How much herbicide active ingredient would it take for a recommended dosage of 3 ppm for 1 acre foot of water?
A. 5.4
B. 3.0
C. 8.1
D. 6.0
38. Correct Answer: D, ILL
Explanation: There are nine essential considerations before using herbicides to control weeds in a pond. Clarity of water can effect the amount of weeds present, but has little effect when determining herbicides to be used.
39. Correct Answer: B, ILL
Explanation: Copper sulfate is a contact herbicide. Direct exposure of the algae to the compound is required and good distribution in the water where the plants are growing is essential.
40. Correct Answer: C, ILL
Explanation: Copper sulfate is greatly affected by carbonate alkalinity of the water. Higher concentration of copper sulfate are usually required to control plants in hard, alkaline waters than in softer, acid waters.
41. Correct Answer: D, ILL
Explanation: Copper chelates are considerably more expensive per unit of copper than copper sulfate.
42. Correct Answer: A, ILL
Explanation: Fish are extremely sensitive to the amine salt (particularly the liquid formulation), but not to the potassium salt.
43. Correct Answer: A, OPM
Explanation: A potassium salt is available in both liquid and granular formulations of endothall. Fish are extremely sensitive to the amine salt, but not the potassium salt.
44. Correct Answer: B, ILL
Explanation: When diquat is added to water, diquat dissociates to form a cation. This property makes the compound extremely susceptible to adsorption to negatively charged clay and organic matter. In muddy waters, the diquat will be tied up by the organic matter and clay, and will be inactivated.
45. Correct Answer: A, ILL
Explanation: Casoron is formulated as a granule and is applied to the water or to exposed sediments in early spring before the weeds emerge.
46. Correct Answer: B, ILL
Explanation: In general, 2,4-D is not as effective on underwater plants as it is on terrestrial plants. An exception is the granular ester formulation of 2,4-D, which is effective on watermilfoil and coontail.
47. Correct Answer: B, ILL
Explanation: Plants should be treated when they are 3 to 4 feet tall and before they form flowering heads.
48. Correct Answer: E
Explanation: There are no restrictions when used for these purposes.
49. Correct Answer: A, OPM
Explanation: Fluridone is a systemic aquatic herbicide that inhibits a plant's ability to make food. This process takes 30 to 90 days to work so treatment early in the growing season is recommended.
50. Correct Answer: C, ILL
Explanation: The correct amount of formulated herbicide to use per acre-foot of water in order to give the required parts per million is usually provided in a table on the herbicide labe. The amount can also be calculated easily if the following relationship is used. Since an acrefoot of water weighs approximately 2.7 million (2,718,144) pounds, 2.7 pounds of any material dissolved in 1 acre-foot of water will equal 1 part per million by weight. Therefore,
Pounds required = 2.7 lb x ppm desired x acre-ft required
Pounds active ingredient = 2.7 lb x 3 ppm x 1 acre ft. = 8.1 Ibs.