Chapter 15

Question 1

It is natural for weeds to fill empty niches in cropping systems

Answer 1

True

Question 2

Weeds can be classified by the environments in which they grow

Answer 2

True

Question 3

Crop plants are never weeds

Answer 3

False

Question 4

Biennial weeds flower in the first year

Answer 4

False

Question 5

Most dicots are easier to kill by cultivation than monocots

Answer 5

True

Question 6

A weed must be alive in order to demonstrate allopathic properties

Answer 6

False

Question 7

Over 95% of the corn, soybean and cotton crops grown are treated with herbicides

Answer 7

True

Question 8

Weeds can interfere with harvesting equipment

Answer 8

True

Question 9

Weed seed tends to be bigger than crop seed

Answer 9

False

Question 10

Animals do not have a significant role in weed dispersal

Answer 10

False

Question 11

Insecticides are used more than any other pesticide

Answer 11

False

Question 12

It is a violation of federal law to use an herbicide in a manner inconsistent with its labeling

Answer 12

True

Question 13

Selective herbicides affect almost all plants

Answer 13

False

Question 14

Different crops species select for different weed species

Answer 14

True

Question 15

A disadvantage of biological control is the possibility of affecting non-target species

Answer 15

True

Question 16

Tillage is an effective strategy of weed control regardless of weed species

Answer 16

False

Question 17

The main concern with atrazine is leaching and accumulation in surface and groundwater

Answer 17

True

Question 18

A plant can be classified as a weed if it:
A. Causes economic loss to a crop
B. Is harmful to humans and livestock
C. Is detrimental to wildlife or ecosystem
D. All answers are correct

Answer 18

D. All answers are correct

Question 19

Weeds that are especially injurious are classified by the government as: 
        A. Toxic 
        B. Noxious 
        C. Non-Native 
        D. Exotic

Answer 19

B. Noxious

Question 20

The long-term persistence of a certain annual weed species is most likely due to: 
        A. Extensive root system
        B. Herbicide resistance 
        C. High seed production 
        D. Tolerance to tillage

Answer 20

C. High seed production

Question 21

A weed that reproduces asexually is most likely:
A. An Annual
B. A Biennial
C. A Perennial
D. None of these answers are correct

Answer 21

C. A Perennial

Question 22

Milk sickness is caused when people drink milk from cows who have consumed which weed? 
        A. Poison Ivy 
        B. Musk Thistle 
        C. Pigweed 
        D. White Snakeroot

Answer 22

D. White Snakeroot

Question 23

The first defense against weeds is: 
        A. Prevention of establishment 
        B. Herbicides 
        C. Tillage 
        D. Biocontrols

Answer 23

A. Prevention of establishment

Question 24

Which agency of the USDA is responsible for preventing the introduction of noxious weeds? 
        A. EPA 
        B. APHIS 
        C. ARS 
        D. NRCS

Answer 24

B. APHIS

Question 25

``` Which agency is responsible for approving new herbicides? A. EPA B. APHIS C. ARS D. NRCS ```

Answer 25

A. EPA

Question 26

``` In what year were genetically engineered crops first introduced? A. 1991 B. 1993 C. 1996 D. 1998 ```

Answer 26

C. 1996

Question 27

``` Which type of ingredients are added to a herbicide formulation to facilitate application and handling or to increase activity? A. Active Ingredients B. Inert Ingredients C. Chemical Ingredients D. Restricted Ingredients ```

Answer 27

B. Inert Ingredients

Question 28

``` LD50 is a measure of: A. Dispersion B. Toxicity C. Activity D. Suspension ```

Answer 28

B. Toxicity

Question 29

``` The mode of action of glyphosate is: A. Growth Regulator B. Photosynthesis Inhibitor C. Amino Acid Synthesis Inhibitor D. Cell Membrane Disrupter ```

Answer 29

C. Amino Acid Synthesis Inhibitor

Question 30

``` The mode of action for 2,4-D is: A. Growth Regulator B. Photosynthesis Inhibitor C. Amino Acid Synthesis Inhibitor D. Cell Membrane Disrupter ```

Answer 30

A. Growth Regulator

Question 31

``` The mode of action for atrazine is: A. Growth Regulator B. Photosynthesis Inhibitor C. Amino Acid Synthesis Inhibitor D. Cell Membrane Disrupter ```

Answer 31

B. Photosynthesis Inhibitor

Question 32

``` Which type of herbicide is applied to foliage? A. Pre Emergence B. Pre Plant C. Systemic D. Contact ```

Answer 32

D. Contact

Question 33

``` Which type of herbicide would be most useful on an established perennial weed? A. Pre Emergence B. Pre Plant C. Systemic D. Contact ```

Answer 33

C. Systemic

Question 34

``` Which would NOT be an appropriate strategy to prevent herbicide resistance? A. Crop Rotation B. Using Extra Herbicide C. Herbicide Rotation D. Tillage ```

Answer 34

B. Using Extra Herbicide

Question 35

``` Grassy weeds would be easiest to control in which crop? A. Corn B. Wheat C. Soybean D. Oats ```

Answer 35

C. Soybean

Question 36

Weeds that live on land are classified as ________, whereas those that are a problem in water are _______

Answer 36

Terrestrial and Aquatic

Question 37

The three life cycles weeds can be classified by are _______, _______ and _______

Answer 37

Annual, Biennial and Perennial

Question 38

_______ annual weeds are those that germinate in the fall, are vegetative in the winter and flower in the following spring

Answer 38

Perennial

Question 39

Biennial plants require _______ season to complete their life cycle

Answer 39

Two

Question 40

Rye infected with Claviceps purpurea forms ________

Answer 40

Ergot

Question 41

The reservoir of weed seeds in the soil is called the ______

Answer 41

Seed Bank

Question 42

Weed can develop _______ to herbicides with detoxifying or morphological modifications

Answer 42

Biotypes

Question 43

The most widely used herbicide is ________

Answer 43

Round Up

Question 44

On its label, an herbicide has three names, including the _______ name, the _______ name and the _______ name

Answer 44

Common, Trade and Chemical

Question 45

_______ use pesticides present little danger to humans or the environment, whereas _______ use pesticides are harmful to humans or the environment

Answer 45

General and Ristricted

Question 46

The types of herbicide application based on timing are _______, ________, ________ and ________

Answer 46

Pre-plant, Pre-Emergent, Post-Emergent and Post-Harvest

Question 47

Bull Thistle

Answer 47

Biennial

Question 48

Pigweed

Answer 48

Summer Annual

Question 49

Jimson Weed

Answer 49

Summer Annual

Question 50

Bermuda Grass

Answer 50

Perennial

Question 51

Canada Thistle

Answer 51

Perennial

Question 52

Velvetleaf

Answer 52

Summer Annual

Question 53

Leafy Spurge

Answer 53

Perennial

Question 54

Shepherd's Purse

Answer 54

Winter Annual

Question 55

Dandelion

Answer 55

Perennial

Question 56

Musk Thistle

Answer 56

Biennial

Question 57

Johnsongrass

Answer 57

Perennial

Question 58

Chickweed

Answer 58

Winter Annual

Question 59

Caution

Answer 59

Category III

Question 60

Warming

Answer 60

Category II

Question 61

Danger

Answer 61

Category I

Question 62

Poison

Answer 62

Category I