R2103 2 WEEDS Flashcards
Definition of a weed
A plant is growing out of place
How weeds can cause problems
- It can reduce plant growth by competing with cultivated plants for light, nutrients and water
- Reduces the visual appeal of planting
- Act as alternate hosts
Ephemeral weeds definition
Type of weeds that complete multiple growing cycles in one year
Annual weed definitiol
Type of weed that completes its life cycle in one growing season
Perennial weed
Weeds that live through several growing seasons
Weeds in hort. situations: Recently cultivated soil
Ephemeral and annual - seeds germinate when they are brought up to soil surface by cultivating
Perennials - rhizomous roots can get chopped upwhile cultivating, resulting in wider weed spread
Weeds in hort. situations: herbacous perennial border
Ephemerals and annuals - usually germinate earlier than herbaceous perennials appear depriving small shoots of light. Also unsightly
Perennials - grow rather large, difficult to remove
Weeds in hort. situations: Woody perennial plantings
Competition, looks unsightly
Weeds in hort. situations: lawns
Low growing weeds difficult to remove as they are the same level as the lawn. Bellis perennis - flowers which might be undesired
Herbicides: contact
Enter the leaf or the stem and kills the tissue of susceptable plants in the particular area where they have entered
Suitable for annual weeds i.e. on waste grounds
Active ingredient: diquat
Herbicides: systemic or translocated
Enter the leaf or the stem and then move via vascular system to reach all parts of the plant including the roots
Good for: perennial weeds i.e. growing through the cracks of the patio
Active ingredient: Glyphosate
Herbicides: selective
Are able to kill chosed weed specials through the leaf but leave the surrounding garden plants unaffected
Used for killing broadleaf weeds in a lawn while keeping the grass unaffected
Active ingredient 2,4-D
