Unit 3 Crop Protection Flashcards
Describe 3 things can reduce crop productivity?
- weeds
- invertebrate pests
- disease
How to weeds reduce crop productivity?
Weeds are a problem due to competition
They compete for light, water, soil nutrients and space
How do invertebrate pests reduce crop productivity?
Invertebrate pests such as nematodes,molluscs and insects
They damage leaves of roots and can act as parasites or disease vectors
Name 3 pests and the type of pesticide that can be used on them?
Insects- insecticide
Molluscs- molluscicide
Nematodes-nematocide
What 3 pathogens cause plant disease?
Fungi
Bacteria
Virus’
Give three ways that pathogens can spread from plant to plant:
Soil borne
Air borne
Insect vectors
What is the main type of pesticides used against plant diseases?
Fungicides
Why do fungicides often have to be reapplied?
Due to rain washing it off and leaving the plant unprotected
How do farmers know when it is best to supply these pesticides to crops to combat diseases such as Patrao blight?
By using techniques such as the smith period or by using weather forecasting
Properties of annual weeds:
Grow very quickly
Rapidly produce flowers as short life
Produce large numbers of seeds
Seeds can live gears under ground before needing to grow
Properties of perennial weeds:
Already established in the habitat
Have storage organs
Are able to reproduce veagativley
3 examples or cultural control:
Crop rotation
Ploughing
Early weed removal
Why is crop rotation good?
As it limits the effects of soil inhibiting pests by changing the crop type
Why is ploughing good?
As it burries and destroys perennial weeds
Why is early weed removal good?
Allows crops to grow bigger and tolerate competition
What type of pesticide is used on weeds?
Herbicide
What type of plants do selective herbicides have a greater effect on?
Broad leaved plants
What is the difference between contact and systemic herbicide?
Systemic herbicides are absorbed and transported through the plant’s vascular system, killing the entire plant.
Contact herbicides kill the part of the plant in contact with the chemical but the roots may survive and the plant may regrow.
What does biological control involve?
Reduction of a pest population by deliberate introduction of its natural enemy
What’s 3 risks associated with biological control?
It may become and invasive species
It may prey on other species
It may infect other species
What is intergrated pest management (IPM)?
Combination of techniques including chemical control
cultural control
biological control
as well as host plant resistance
List three problems with chemical control:
Chemicals are not short lived
Chemical resistance
Not specific
What is bioaccumulation?
Bioaccumulation is the buildup of chemicals per animal
What is biomagnification?
The increase of concentration of a chemical between trophic levels
