test 2 quizzes meed mgmt

If a plant survives application of a contact herbicide then you will see new green leaves emerge, but after an application of an apoplastic herbicide new leaves will be deformed and discolored.

false

Which of the following is an example of a contact herbicide?

glufosinate

A systemic herbicide may be applied on the soil or on the leaves.

true

Apoplastic herbicides move through the phloem.

false

Herbicides that move in the symplastic system always do downwards in the plant towards the roots.

false

Photosynthesis occurs within which cell organelle?

chloroplast

Atrazine is an important herbicide because: 

it is the main corn herbicide

Contact herbicides translocate within the plant.

false

Contact herbicides kill/damage a plant by disrupting what process in the weed?

photosynthesis

Cells must be disrupted in their normal processes through all of the following ways except:

duplication

If a contact herbicide does not have proper coverage across a whole plant or even a leaf what is expected?

injury and chemical burn at the site the droplet landed on the leaf

Symplastic herbicides move through the phloem.

true

Symptoms of apoplastic herbicide include:

older, mature leaves have chlorosis and necrosis

Paraquat takes about 12 hours regardless of the temperature to begin to see symptoms effects.

false

Contact herbicides can cause flower abortion on a plant in reproductive stages.

true

Using a contact herbicide on annual or biennial plants provides a high likelihood of killing the plant.

true

Apoplastic herbicides must pass through this barrier to enter the xylem:

casparian strip

Which of the following is an apoplastic herbicide?

atrazine

What description(s) best align(s) with the symplastic system?

• Phloem movement, transports sugars, source to sink

Herbicides that move in the apoplastic system always move with the direction of water movement in the plant.

true

The Palmer Amaranth plant is monoecious meaning that the male and female flowers are found on separate plants, not on the same individual plant.

false

The downside of using a row crop cultivator in a young crop field is that it will discourage the crop to grow taller.

false

An effect of target or non-target drift of chemical herbicides during flowering of a weeds is:

delayed flowering, reduced seed production

What is the growth deformity caused by 2,4-D?

epinasty

Symplastic herbicides often move to the apical meristem of the growing plant, which results in:

stopping normal growth, discoloration of young developing leaves, deformed new leaves and stems

What time of year is the generally the most difficult to control weeds using symplastic herbicides?

mid to late summer when the weather is hot and dry

Symplastic herbicides must pass through what to enter the plant?

leaf cuticle