Topic 2 Element 3 - Plant competition Flashcards
Why control weeds?
- they compete with desired plants for light, nutrients and water
- lack of aesphetic appeal
- act as hosts to pests and pathogens
**Capsella bursa-pastoris **
can host and spread Brassica diseases white blister and clubroot as well as host aphids
How can weeds be helpful?
- can be used as cover crops
- help recycle nutrients, deep rooted weeds bring nutrients from lower in the soil into foliage
- help to support wildlife and pollinators
- can give you an indication of soil type
What is a cover crop?
Cover crops prevent soil erosion, intercept rainwater and sustain year round ecosystem when soil would otherwise be bare.
Cultural ways to control pest, diseases and weeds?
- increasing crop/desired plant density
- crop rotation
- mulching to suppress
Benefits of cultural control?
- effects usually sustained
- easily incorporated into garden routines
Limitations of cultural control?
- can be slow to take effect
- increasing density may cause desired plants to compete
Physical ways of controlling pests, diseases and weeds
- hoeing / thermal weeding
- mechanical brushing
- hand removal of weeds
- digging out weeds
Benefits of Physical control?
- very targeted
- enables weeds to decompose and feed soil (hoeing)
Limitations of Physical control?
- may need repeating
- time consuming
- digging out weeds can release carbon dioxide and destroy mycorrhizal fungi networks
What is Chemical control of pests, diseases and weeds?
Application of chemicals to prevent or kill a pest, disease of weed.
What does Pesticides refer to?
Refers to herbicides, insecticides, fungicides and other similar substances that prevent or kill pests, diseases and weeds.
Benefits of Chemical control?
- is quick to deal with the problem
- can be targeted
Limitations of Chemical control?
- Herbicide drift can harm other plants
- can be dangerous to humans, pets desired plants and other wildlife
- Many herbicides have been withdrawn from commercial use as evidence grows that some are carcinogenic
- harmful to earthworms and other soil organisms
What is a contact herbicide?
They enter the leaf or stem and kill only the tissue it comes into contact with.
What is a translocated herbicide?
They translocate down the plant via the phloem from where they were applied usually the leaves.
What is a selective herbicide?
Selective herbicides target only particular weeds. Generally used in lawns to kill eudicotyledonous weeds in grass.
What licenses are required to apply pesticides?
- PA1
- PA6
What does The Weed Act (1959) require?
This act requires landowners by law to control injurious weds on their property.
Cirsium vulgare
Cirsium arvense
Rumex crispus
Rumex obtusifolius
Senecio jacobaea
What is a pernicious weed?
A pernicious weed is a plant that is harmful, invasive and destructive to other plants.
What is the latin name for Japanese Knotweed?
Fallopia japonica
What act prohibits Fallopia japonica to grow in the wild?
The Wildlife & Countryside Act (1981)
What form is requires sellers of a property to detail the presence and location of Fallopia japonica. As well as an eradication plan to be performed by a contractor?
TA6
Where must Fallopia japonica be disposed of?
Licenced landfill
