higher bio unit 3 ka3

The differences in crop plants when facing weeds and pests/ diseases

Weeds compete with crop plants While pests and diseases damage crops

state the two types of weeds

Annual and perennial

State the properties of the annual weed

They have short life cycles, rapid growth, high seed viability and high seed output

State the properties of the perennial weed

They have storage organs and vegetative (asexual) reproduction

State cultural methods of crop protection

Weeding , crop rotation and ploughing

What are pests of crop plants

They are invertebrates such as molluscs, insects and nematode worms

What are diseases caused by in crops

Bacteria, fungi or viruses often carried by invertebrates

What are the 3 types of pesticides

Selective herbicides, systematic insecticides and systematic herbicides

What are selective herbicides

pesticides that are more effective with specific species of plants

What are systematic insecticides

pesticides that travel through the plant and kill the pests eating the crops

What are systematic weed killer

Spread through the vascular system of the plant including underground storage organs and prevents growth

Problems with pesticides (4)

The toxicity to non target species

Persistence in the environment

bioaccumulation

Biomagnification

What is bioaccumulation

The build up of chemicals in an organism

What is Biomagnification

increase in concentration of chemicals as you move up the trophic levels

What is biological control

The introduction of a predator, parasite or pathogen to kill pests

What’s the risk with biological control

The control organism can become an invasive species

What is integrated pest control

The combination of biological, chemical and cultural control to control pests and diseases