Key Area 3-Crop Protection

Question 1

What are factors that can reduce a crop’s yield?

Answer 1

• pests
• diseases
• competition from weeds

Question 2

How do factors reduce yield?

Answer 2

Reduce productivity

Question 3

What are annual weeds?

Answer 3

Weeds that complete their entire lifecycle in one year

Question 4

Give four features of annual weeds

Answer 4

• short life cycle
• rapid growth
• large quantities of seeds are produced
• seeds are viable for a long period of time

Question 5

What are perennial weeds?

Answer 5

Plants that live for several years, becoming dormant in winter and growing again in the spring

Question 6

Give two features of perennial weeds

Answer 6

They have storage organs for food for environments that don’t favour growth
They reproduce asexually using methods like runners: leads to rapid reproduction

Question 7

What are pests?

Answer 7

Thy damage plants, usually invertebrates

Question 8

What are the three groups of pests?

Answer 8

Nemotide worms: in the soil and attack the plants roots
Molluscs: snails/slugs destroy crops by eating leaves
Insects: damage plants by feeding on them

Question 9

Describe diseases:

Answer 9

Mainly carried by invertebrates

Microorganisms: fungi/bacteria/viruses

Question 10

What are three methods of control for weeds, pests and diseases?

Answer 10

Cultural
Biological
Chemical

Question 11

What is cultural control?

Answer 11

Using traditional farming methods to protect plants

Question 12

What are two methods of cultural control?

Answer 12

Ploughing-too layer of soil is turned over causing perennial weeds to be removed and buried, and decompose
Crop rotation-crops grown in a cycle in a field to break life cycle of pests specific to one crop

Question 13

What are herbicides, pesticides and fungicides?

Answer 13

Chemicals sprayed to kill weeds(herbicides), pests(pesticides) and prevent growth of fungus(fungicides)

Question 14

Describe the two types of herbicides and an advantage of each

Answer 14

Selective: only effect broad leaves plants~doesn’t affect any crops
Systemic: absorbed into transport system of plant~prevents regrowth of the weed

Question 15

Describe the two types of pesticide

Answer 15

Contact: kill pests on the leave at time of spraying
Systemic: absorbed by the root and transported through the plant so any pests who tries to feed from the plant will be poisoned

Question 16

Describe the two types of fungicides

Answer 16

Contact: prevents new fungus growth
Systemic: absorbed by the roots and transported through the plant to protect all part of the plant

Question 17

Why are disease forecasts used when spraying fungicides?

Answer 17

Disease forecasts allow you to judge when to spray the fungicide based from when the optimal conditions are

Question 18

What are four problems associated with plant protection chemicals?

Answer 18

• may be toxic to animal species
• can be persistent
• can accumulate in food chains
• can create resistant populations

Question 19

What does pesticide resistance mean?

Answer 19

Chemicals in the pesticide do not break down and remain in the environment for a long period of time

Question 20

What does magnification of pesticides in the food chain mean?

Answer 20

Organisms higher up the food chain consume more biomass and contain more fat so are found to contain more toxins

Question 21

What does selection pressure mean?

Answer 21

When pesticides are sprayed onto a field it creates a selection pressure so only pests who are resistant to pesticides survive

Question 22

What is biological control?

Answer 22

When a predator species is introduced to eradicate pest species

Question 23

What are the risks of biological control?

Answer 23

Timing is crucial: if the species isn’t released at the time when the pest species is active it will be less effective
Controlled environment: species can escape if not released contained therefore controlled environments are better as the predator can not escape and conditions can be maintained as optimum

Question 24

What is integrated pest management?

Answer 24

A combination of biological, cultural and chemical control methods are used with an emphasis on control, not eradication, of the pest