Agronomy 105 Lab Quiz 8

  1. Photosynthesis provides what to a plant?
  2. What is Mode of Action?
    Sequence of events from the absorption of the herbicide into the plant until the plant dies
  3. Understanding Mode of Action is important because?
    • Better understanding how herbicides perform
    • Improve herbicide performance
    • Diagnosing herbicide injury
    • Prevent and manage herbicide resistance
  4. Why do we use herbicides?
    Reduce the impact of invasive species and to secure the presence of targeted species
  5. What is a selective herbicide?
    • Controls or suppresses one species of plant without seriously affecting the growth of another plant species
    • Ex: 2,4-D
  6. What is a nonselective herbicide?
    • Controls plants regardless of species
    • Ex: Round-Up
  7. What are the two types of absorption?
    Root contact and foliar contact
  8. What type of translocation is found in the xylem?
    Upward movement only
  9. What type of translocation is found in the phloem?
    Both upward and downward movement
  10. Plant Growth regulators are; selective or nonselective?
  11. Plant growth regulators affect what?
    Cell division, cell enlargement, protein synthesis and respiration
  12. Plant growth regulators act how?
    Act by upsetting the normal hormonal balance in plants
  13. Primary growth regulators trans-locate how?
    Through the xylem and phloem
  14. What plants do Plant Growth Regulators affect and name an example.
    • Broadleaf plants
    • Ex: 2,4-D
  15. What are some concerns concerning plant growth regulators?
    • Herbicide resistance, drift and injury to non-target plants
    • Ex: Groundwater contamination- Tordon
  16. What are some symptoms linked to Plant Growth Regulators?
    Twisted stems, stems swelling- due to rapid cell division, leaves crinkle or cupping
  17. What are amino acid biosynthesis inhibitors?
    Prevent synthesis of certain amino acids produced by plants
  18. Is amino acid biosynthesis inhibitors; selective or nonselective?
  19. How does amino acid biosynthesis inhibitors translocate?
    Both xylem and phloem
  20. How long does it take for a plant to die after administering amino acid biosynthesis inhibitors?
    Plant death is slow- 10+ days
  21. What is an example of amino acid biosynthesis inhibitors?
    Telar, Round-Up
  22. What are some symptoms of amino acid biosynthesis inhibitors?
    Chlorosis of leaves and necrosis eventually, stunted growth
  23. What is an example of an ESPS Inhibitor, which is an important category for the amino acid biosynthesis inhibitors?
    • Glyphosphate
    • Ex: Round-Up
  24. Photosynthetic Inhibitors shut down what?
    The photosynthetic process
  25. What are some injury symptoms of Photosynthetic Inhibitors?
    Chlorosis of leaves followed by necrosis, also a slow starvation of the plant
  26. What is an example of Photosynthetic Inhibitors?
    Spike 20
  27. When does Photosynthetic Inhibitors start working?
    Only occurs after the cotelydons and the first leaves emerge
  28. True or False: Photosynthetic Inhibitors affect older and larger leaves first
  29. Cell Membrane Disruptors are; selective or non-selective?
  30. How does Cell Membrane Disruptors work?
    Activated by exposure to sunlight to form compounds that destroy plant tissue by rupturing cell membranes
  31. How long does it take to control weeds using Cell Membrane Disruptors?
    24 to 48 hours
  32. What is an example of Cell Membrane Disruptors?
    Gramoxone Max
  33. What are symptoms of Cell Membrane Disruptors?
    Rapid necrosis
  34. Herbicide Resistance is not due to:
    sprayer skips, weather problems, poor control, "naturally tolerant' plants, or genetic changes caused by the herbicide
  35. Herbicide Resistance is defined as?
    Ability of a plant to survive and reproduce after treatment with a dose of herbicide that would normally kill the plant
  36. Your selection intensity depends on?
    • Herbicide efficacy
    • Length or soil residual period 
    • Number of herbicide applications per year
Card Set
Agronomy 105 Lab Quiz 8
Herbicides Agro 105