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