Crop Protection Flashcards
What are weeds?
Crop weeds grow among crops and reduce yield by competing with crops for resources.
What are the 2 types of weeds?
Annual
Perennial
What are annual weeds?
Grow from seeds and complete their life cycle in 1 year.
Short life cycle.
Produce many seeds (viable for long periods)
Grow quickly after germination.
What are perennial weeds?
Persist from year to year.
Storage organs.
Vegetative reproduction (e.g. runners and tubers)
What are the 3 types of pests?
Nematodes
Molluscs
Insects
What are diseases?
Caused by micro-organisms- often carried by invertebrates acting as parasitic vectors.
What are the 3 types of diseases?
Fungus
Bacteria
Viruses
What are the cultural methods of control?
Preventative and uses no chemicals.
e.g. deep ploughing (damages/buries perennial weeds)
e.g. crop rotation (specific pests die out between plantings of the same crop)
What are the chemical control methods?
Herbicides
Fungicides
Insecticides
What are selective herbicides?
Over stimulates plant metabolism.
Kills leafy part of plant (broad leaved plants only)
What are systemic herbicides?
Absorbed and transported through vascular system of plants.
Totally destroys whole plant and prevents regeneration.
What are fungicides?
Kills fungal parasites.
Often sprayed on crops- can be used to protect crops when forecasts predict infections.
What are insecticides?
DDT is an insecticide- as it is persistent, it stays in the ecosystem and gets passed along the food chain accumulating in predators at the end.
Insecticides can also damage non-target insects.
What is bioaccumulation?
A build-up of chemical in an organism.
What is biomagnification?
An increase in the concentration of a chemical moving between trophic levels.
What is biological control?
This involves introducing a predator, parasite or pathogen to deal with a pest.
What’s an advantage of biological control?
No chemicals to persist in environment.
What’s a disadvantage of biological control?
Risk of biological control agents escaping into natural ecosystems.
What is integrated pest management?
Combination of cultural, chemical and biological control.
This allows the use of chemicals to be reduced.
