3.3 crop protection

Question 1

What is a weed

Answer 1

-plants that grow in an area that are unwanted and reduce the productivity of crops

Question 2

What are the 2 types of weed

Answer 2

• annual

- perennial

Question 3

What are the characteristics of a weed that is annual

Answer 3

• short life cycle (around a year)
• rapid growth rate
• high output of seeds
• seeds have a long time viability

Question 4

What are the characteristics of a weed that is perennial

Answer 4

• long life cycle (several years)
• asexual
• have storage organs to provide food in poor conditions

Question 5

What is a pest

Answer 5

• something that feeds upon crop plants

- usually invertebrates like insects, nematodes, mollluscs

Question 6

What is another factor that can affect the productivity of the crop plants

Answer 6

• disease
• often carried by invertebrates
• can be caused by fungi, bacteria, viruses

Question 7

Define cultural methods of crop protection

Answer 7

-a technique for controlling weeds, pests and diseases that doesn’t use chemicals

Question 8

Give 3 examples of cultural methods

Answer 8

• ploughing
• crop rotation
• weeeding

Question 9

Describe the cultural method - weeding

Answer 9

• the removal of weeds from the soil, reducing competition with the crop plants
• should be done as early as possible when weeds grow

Question 10

Describe the cultural method - ploughing

Answer 10

-turning and loosening the top layer of soil and burying weeds deeper underneath leading them to die and decompose

Question 11

Describe the cultural method - crop rotation

Answer 11

-the process of growing different crops one after the other on the same piece of ground over several growing seasons

Question 12

Define pesticides (chemical method)

Answer 12

• a group of chemicals that kill any pests that are harmful to the growth of crops
• can be selective or systemic

Question 13

What does a herbicide kill

Answer 13

Weeds

Question 14

What chemical kills weeds

Answer 14

Herbicide

Question 15

What chemical kills fungal disease

Answer 15

Fungicide

Question 16

What does fungicide kill

Answer 16

Fungal disease

Question 17

What does insecticide kill

Answer 17

Insects

Question 18

What chemical kills insects

Answer 18

Insecticide

Question 19

What does molluscicides kill

Answer 19

Molluscs

Question 20

What chemical kills molluscs

Answer 20

Molluscicide

Question 21

What chemical kills nematodes

Answer 21

Nematocides

Question 22

What does nematocide kill

Answer 22

Nematodes

Question 23

What does a selective herbicide do

Answer 23

-has a greater effect on specific plant species (broad leaved weeds)

Question 24

What does a systemic insecticide, molluscicides and nematocides do

Answer 24

-spread through vascular system of plants and kills pests that feed on the plant

Question 25

What does a systemic herbicide do

Answer 25

More

Question 26

what are some of the problems when using a pesticide

Answer 26

• toxic to non-target species
• persistence in the environment
• production of resistant population of pests
• bioaccumulation
• biomagnification

Question 27

Define bioaccumulation

Answer 27

-build up of the pesticides within an organism

Question 28

Define biomagnification

Answer 28

-increase in pesticide concentration going from one tropic level to the next in a food chain

Question 29

Define biological control

Answer 29

-the introduction of a natural control agent to that of the pest

Question 30

Give problems of biological control

Answer 30

• the control agent might become an invasive species, meaning it may cause potential harm to the environment it has been introduced to
• the control agent may also become a parasite, pathogen or prey upon other species that it was not introduced to remove

Question 31

Define integrated pest management

Answer 31

• involves a combination of chemical, biological and cultural control
• should be controlled in a manner where chemicals are only used when essential alongside other methods that are not harmful to the environment