Controls Flashcards
Explain what is meant by cultural control, with three examples.
A procedure or manipulation of the growing environment, that results in the prevention of weeds, pests, diseases or disorders.
EG:
Right plant, right place
Companion planting
Crop rotation
Cultivation of soil
Maintaining soil fertility and water content
Maintenance of equipment (hygienic and sharp)
State benefits and limitations of using cultural controls.
Benefits:
Easy to fit in with regular routines
Has long lasting positive effects eg. weeding removes vectors for pests and diseases, and stops competition for water and nutrients at the same time.
Limitations:
Time consuming
Slow acting compared to other methods
Explain what is meant by physical control, with three examples.
A material, mechanical or hand control where the weed/disease/pest/disorder is either prevented from occurring or blocked or destroyed when it does occur.
EG:
Can be part of cultural controls, eg Weeding or cultivation of soil to expose pests to their predators
Barriers - Fences (against rabbits or deer); Netting (against wood pigeons and cabbage white butterfly); Mulches (to prevent weed growth); Fleece (low fence to prevent carrot fly or over whole crop to stop frost damage)
Traps - Pheromone traps (Plum or codling moth); Glue bands or sticky traps (flightless pests/greenfly etc)
Deterrents - companion planting (onions next to carrots to deter carrot fly); Ammonia or Citronella sprays (to deter foxes and rabbits)
State benefits and limitations of using physical controls.
Benefits:
Long lasting eg Fence/plastic sheeting
Usually low maintenance eg Fence/plastic sheeting
Limitations
Expensive eg Fence
Health and safety considerations eg use of tools (rotivators, flame throwers), safe handling of waste material (disposing of diseased or damaged material safely)
Explain what is meant by Biological control, with three examples.
Use of natural enemies to reduce damage caused by pest or disease.
EG: Frogs and toads eat slugs Hedgehogs eat slugs, beetles caterpillars etc Lacewings (adults and larvae) eat aphids and mites Ladybirds (adults and larvae) eat aphids Hoverfly larvae eat aphids Wasps eat caterpillars Birds esp tits eat aphids Birds esp thrushes eat slugs
Attract more wildlife to your garden by providing a suitable habitat - shelter and food. eg a pond with shallow edge to enable frogs or toads to enter and leave, put out bug hotels and bird boxes, feed birds in winter and hope they stick around, ensure planting is varied (avoiding monocultures) and offers insects year round food.
Parasitic animals can also be helpful in a protected environment, such as a commercial greenhouse, where certain types of wasp or nematode are introduced to deal with pest problems.
State benefits and limitations of using Biological controls.
Benefits:
Non-toxic to humans
Balanced pest/predator population develops naturally
No build up of resistance
Limitations
Needs careful timing if introducing new organisms to environment to avoid altering the natural balance
Will be affected by use of chemical controls
Explain what is meant by Chemical control, with three examples.
Use of chemical substance (can be man made or naturally occurring) to prevent or kill pests, weeds, or diseases.
EG:
Herbicides - Contact (Fatty Acids)
- Translocated (Glyphosate)
- Selective (2,4-D)
Fungicides - Bordeaux mixture
- Myclobutanil
Molluscicides - Ferric phospate
- Metaldehyde (banned)
Insecticides - Deltamethrin/Pyrethrin
- Fatty Acids
State benefits and limitations of using Chemical controls.
Benefits:
Treatment is usually successful as long as directions are followed carefully
Fast acting
Easily accessible
Limitations:
Dangerous to humans and animals, including beneficial insects and pets
Resistance can develop
Must be use sparingly to prevent accumulation in soil/environment
Careful use, storage and disposal are required to avoid affecting the natural balance within the application area, damage to the local environment, and more widespread damage such as water contamination.
Describe how knowing the life cycle and biology of weeds helps in their control
Knowing what to expect from different weeds helps select the most effective response method.
Eg, Ephemeral weeds need to be dealt with quickly before they set seed, can be easily pulled up by hand or hoed out as they have shallow roots and will not regenerate from their roots. Contact weedkillers will be effective.
Describe how knowing the life cycle and biology of pests helps in their control
Knowing the life cycle of common pests helps gardeners interrupt that cycle at the most appropriate point, or informs which type of controls will be effective at the point of discovery. Knowing the biology of pests can be useful when selecting chemical control methods.
Eg, Chemical and biological control of Vine weevils is possible to deal with the larvae, but not effective on the adult beetles.
Placing netting over (esp Brassica) plants in late spring/early summer will prevent butterflies laying eggs, making other controls unnecessary.
Knowledge of the biology of pests enables effective chemical controls on (for example) insects, such as using plant oils in order to block spiracles (insect breathing holes located on their bodies), or fatty acids to dissolve the waxy cuticles.
