Topic 3: Crop Protection

Question 1

What do weeds compete with?

Answer 1

Crop plants

Question 2

What do pests and diseases damage and why is it bad?

Answer 2

Leaves of crop plants reducing productivity

Question 3

What are the characteristics of annual weeds?

Answer 3

Rapid growth,
short life-cycle,
high seed output,
long-term seed viability

Question 4

What is the competitive adaptation of perennial weeds?

Answer 4

Storage organs, vegetative reproduction

Question 5

What is the category most pests of crop plants arise from?

Answer 5

Invertebrate animals such as; insects, nematode worms, molluscs

Question 6

Plant disease can be caused by what?

Answer 6

Fungi, bacteria, viruses

Question 7

Plant diseases are often carried by what ‘thing’?

Answer 7

Invertibrates

Question 8

What are some cultural methods to control weeds, pests and diseases?

Answer 8

Ploughing, weeding and crop rotation

Question 9

What are the names of some pesticides?

Answer 9

Herbicides, fungicides, insecticides, molluscicides, nematicides

Question 10

What is the function of a herbicide?

Answer 10

To kill weeds

Question 11

What is the function of a fungicide?

Answer 11

Control fungal diseases

Question 12

What is the function of an insecticide?

Answer 12

Kill insect pests

Question 13

What is the function of a molluscicide?

Answer 13

Kill mollusc pests

Question 14

What is the function of a nematicide?

Answer 14

Kill nematode pests

Question 15

Pesticides can be of two categories, what are they?

Answer 15

Selective or systemic

Question 16

What is a selective herbicide?

Answer 16

Have a greater effect on certain plant species (broadleaved weeds),

Mimic the action of natural plant growth substances to stimulate the rate of growth

Question 17

What is a systemic herbicide?

Answer 17

Spreads through vascular system (transport system) of plant and prevents regrowth

Question 18

How do you systemic insecticides, molluscicides and nematicides function?

Answer 18

Spread through the vascular system of plants and kill pests feeding on plants

Question 19

How are fungicides best used?

Answer 19

Based on DISEASE FORECASTS rather than trying to treat already diseased crops

Question 20

Why can spraying diseased crops with pesticides be wasteful?

Answer 20

It is better to use disease forecasting to predict a fungal outbreak and spray before disease spreads

Question 21

What are some problems included with the use of pesticides?

Answer 21

They may be toxic to non-target species,
persistent in environment,
biomagnification,
bioaccumulation,
production of a resistant population of pests

Question 22

What is bioaccumulation?

Answer 22

The buildup of a chemical in an organism

Question 23

What is biomagnification in a food chain?

Answer 23

An increase in the concentration of a chemical moving between trophic levels

Question 24

How can weeds, other pests and diseases be controlled?

Answer 24

By biological control and integrated pest management (IPM)

Question 25

what does Integrated pest management (IPM) include?

Answer 25

combines chemical, biological and cultural control

Question 26

What does biological control involve the use of?

Answer 26

A natural predator, parasite or pathogen of the pest

Question 27

What are the risks with biological control?

Answer 27

• Control organism may become an invasive species

- May parasitise, prey on or become a pathogen of other species