U3 KA3 Flashcards
(23 cards)
1
Q
What are weeds?
A
- plants that compete with crop plants, reducing productivity.
2
Q
What are annual weeds?
A
- weeds that complete a full life cycle in 1 year.
- eg. Annual Nettle.
3
Q
Give 4 properties of Annual Weeds.
A
- rapid growth.
- high seed output.
- short life-cycle.
- long-term seed vitality.
4
Q
What are perennial weeds?
A
- weeds that grow over many seasons
5
Q
Give 2 properties of perennial weeds.
A
- they have storage organs, allowing them to grow into other plants.
- vegetative reproduction.
6
Q
What do pests do?
A
- they damage crop plants, reducing productivity.
7
Q
What are the 3 groups of animals that contain pests?
A
- insects
- nematodes
- molluscs
8
Q
What is a pathogen?
A
- a bacterium, virus or other microorganism that can cause disease.
9
Q
How is plant disease caused?
A
- cause by fungi, bacteria or virus, often transmitted by invertebrates, damaging crop plants.
10
Q
What is cultural control?
A
- a preventative that follows traditional control methods.
11
Q
Give 6 examples of Cultural Control.
A
- Crop Rotation
- Cover Crop
- Destroying Crop Residue
- Ploughing
- Sowing
- Weeding
12
Q
What is Ploughing?
A
- the turning of the topsoil to uproot any underground storage organs.
13
Q
What is Crop Rotation?
A
- not planting the same crop in the same field every year.
14
Q
What is chemical control?
A
- use of pesticides to control pests, diseases or weeds, to improve crop yield.
15
Q
What is a selective herbicide?
A
- a pesticide that has a greater effect on certain plant species.
16
Q
What is a Systemic Herbicide?
A
- a pesticide that spreads through the vascular system of a weed, killing it, and preventing re-growth.
17
Q
What is a Systemic Insecticide?
A
- a pesticide that spreads through the vascular system of a plant, killing the pests that feed on it.
18
Q
What are the negatives of Chemical Control? (3)
A
- toxic to non-target species.
- creates persistence in the environment.
- toxins can bioaccumulate in food chains.
19
Q
What is Bioaccumulation?
A
- a build up of a chemical in an organism.
20
Q
What is Biomagnification?
A
- an increase in the concentration of a chemical moving between trophic levels.
21
Q
What is Biological Control?
A
- removal of a pest species by introducing a control agent that is a natural predator, parasite or pathogen of the pest.
22
Q
What the risks associated with biological control? (2)
A
- control organism may become an invasive species.
- the control organism may become a pathogen, parasite or predator to another species.
23
Q
What is integrated pest management?
A
- the combination of Biological, Chemical and Cultural control methods to control pests and diseases.
