Agronomy Pest and Weed Management 2

Question 1

Which group of insects are important biological control agents for aphids in crops?

Accepted Answer

Ladybugs (lady beetles) and parasitic wasps

Answer

Thrips and spider mites

Answer

Cutworms and armyworms

Answer

Wireworms and white grubs

Question 2

What is herbicide resistance in weeds?

Accepted Answer

Inherited ability of a weed biotype to survive a herbicide dose that kills normal plants

Answer

Temporary tolerance of weeds to low herbicide doses

Answer

Herbicide breakdown before it reaches target weeds

Answer

Weed dormancy triggered by herbicide application

Question 3

Soybean cyst nematode (SCN) is best managed long-term using what strategy?

Accepted Answer

Rotating SCN-susceptible and resistant soybean varieties combined with crop rotation

Answer

Annual nematicide application

Answer

Deep tillage to bury cysts

Answer

Flooding fields during fallow

Question 4

What is a pre-emergent herbicide?

Accepted Answer

A herbicide applied to soil before weed or crop emergence to prevent germination

Answer

A herbicide applied after weeds have emerged and established

Answer

A herbicide that kills only grass weeds

Answer

A herbicide mixed into fertilizer only

Question 5

The corn rootworm beetle's economic damage to corn is primarily caused by what?

Accepted Answer

Larval feeding on roots, reducing water and nutrient uptake and causing lodging

Answer

Adult beetles defoliating leaves

Answer

Beetle feeding on pollen and silks

Answer

Adults boring into stalks

Question 6

Which crop disease is caused by Fusarium graminearum and affects the heads of wheat and barley?

Accepted Answer

Fusarium head blight (scab)

Answer

Septoria leaf blotch

Answer

Powdery mildew

Answer

Crown rust