Organisms that are detrimental to crops And damage them
Give 3 examples of pests And explain how they harm crop yield?
1.insect pests-aphids—eat plant leaves, reducing surface area for photosynthesis—reduced growth and lower yield.
Give an Example of 3 pesticides (chemical control) ?
insecticides—kills insects
herbicides—kills plant pests
fungicides—kills fungal pests
What are the advantages of pesticide?
Increased crop yield By:
working immediately—to kill pests
Kill entire populations of pests
Easily accessible and relatively cheap
what are the disadvantages of pesticides?
1.pests can become resistant to the pesticides
2. You’ll have to Keep reapplying it regularly
3.can kill other beneficial organisms—some insecticide might kill—- bees
4. Wash into rivers and streams—harming organisms in the water
Organic farmers use biological control, what is that?
Using natural predators(ladybird—kill greenfly), (herbivores to eat weeds), parasites, or pathogens to control pests.
What are some advantages of biological control?
No chemicals used—environmentally friendly
Only need to apply once—cost friendly
Long lasting —no resistance
What are some disadvantages of biological control?
takes time to see the effects
Cannot kill entire populations—existing pests
may affect other organisms instead of pests
What is bioaccumulation?
Bioaccumulation refers to the gradual accumulation of substances, such as toxins in the tissues of organisms over time. These substances can enter the food chain through various sources, such as contaminated water or contaminated prey. As organisms consume these substances, they are stored and build up in their bodies. This can lead to higher concentrations of these substances at higher levels of the food chain.
Why is bioaccumulation dangerous ?
toxins (pesticides) build up in the body fat and organs—-can’t be excreted easily. Damage reproductive systems