CCA Weed Identification and Control 2

Question 1

Which weed is characterized by a triangular stem, making it easily distinguishable from grasses?

Accepted Answer

Yellow nutsedge (Cyperus esculentus)

Answer

Yellow nutsedge belongs to the sedge family (Cyperaceae) and has a distinctly triangular stem cross-section, unlike true grasses which have round or flattened stems.

Question 2

What is the primary mode of action for glyphosate herbicides?

Accepted Answer

Inhibition of EPSP synthase in the shikimate pathway

Answer

Glyphosate inhibits 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase, blocking aromatic amino acid synthesis in the shikimate pathway.

Question 3

A field scout identifies a broadleaf weed with alternate leaves, a taproot, and milky latex sap. Which weed is most likely present?

Accepted Answer

Common dandelion (Taraxacum officinale)

Answer

Common dandelion produces milky latex sap when stems or leaves are broken, and has a characteristic deep taproot with a basal rosette of leaves.

Question 4

Which herbicide class is best suited for POST-emergence control of grass weeds in broadleaf crops such as soybeans?

Accepted Answer

Graminicides — ACCase inhibitors (Group 1)

Answer

Graminicides (ACCase inhibitors) such as clethodim and sethoxydim selectively control grass weeds in broadleaf crops without injuring the crop.

Question 5

What weed management strategy involves planting competitive crop varieties and optimizing plant populations to suppress weed growth?

Accepted Answer

Cultural weed control

Answer

Cultural weed control uses agronomic practices—including competitive varieties, optimum seeding rates, and row spacing—to reduce the competitive advantage of weeds.

(CCA) Certified Crop Advisor Practice Test

(CCA) Certified Crop Advisor Practice Test

CCA Weed Identification and Control 2