3.3 Crop Protection Flashcards
What reduces productivity?
- weeds compete with crop plants
- other pests and diseases damage crop plants
What are properties of annual weeds?
- rapid growth
- short life cycle
- high seed output
- long-term seed viability
What are properties of perennial weeds with competitive adaptations?
- storage organs
- vegetative reproduction
What are pests of crop plants and state categories
- invertebrate animals
- insects
- nematode worms
- molluscs
What can plant diseases be caused by and what are they carried by?
- carried by invertebrates
- fungi
- bacteria
- viruses
What are cultural methods of control of weeds, other pests and diseases?
- ploughing
- weeding
- crop rotation
What are the roles of pesticides?
- herbicides to kill weeds
- fungicides to control fungal diseases
- insecticides to kill insect pests
- molluscicides to kill mollusc pests
- nematicides to kill nematode pests
What are selective herbicides?
have a greater effect on certain plant species (broad leaved weeds)
What are systemic herbicides?
spreads through the vascular system of the plant and prevent regrowth
What do systemic insecticides, molluscicides and nematicides do?
spread through the vascular system of plants and kill pests feeding on plants
What are problems with pesticides?
- toxicity to non-target species
- persistance in the environment
- bioaccumulation or biomagnification in food chains
- producing resistant populations of pests
What is the more effective application of fungicides than treating diseased crops?
application of fungicide based on disease forecast
What is bioaccumulation?
a build-up of a chemical in an organism
What is biomagnification?
an increase in the concentration of a chemical moving between trophic levels
What is biological control and what is it used to control?
- the control agent is a natural predator, parasite or pathogen of the pest
- used to control weeds and other pests and diseases
