Selective weed killers
You should know:
Two ways to kills weeds
- Pull out each weed by hand
- Spray lawn with selective weed killers
Most common weed killer – 2,4-D
- 2,4-D ➡️ similar structure to auxins, has greater effect
- Absorbed by broad-leaved plants – accumulates in stem + root tips ➡️ causes uncontrolled growth
- Plant dies, 2,4-D not absorbed by narrow-leaved plants e.g. grass
- Cutting used to produce large numbers of identical plants
- Part of plant is cut off and stem is dipped in rooting powder
- End of stem then placed in compost
- Roots develop from cut stem
- Rooting powders contain auxins ➡️ stimulate the stem cells to develop into roots
- Gas ethane (ethylene) = plant hormone
- Produced by fruits as they ripen
- Stimulate reactions = convert starch into sugar
- "weed killer". Image form the internet.
- "agent orange". Image form the internet.
- "Rooting powders". Image form the internet.
- "Plant Hormones Tissues Tropisms Agricultural Botany Biology 20", https://slidetodoc.com/presentation_image_h/279a370cc367465a13bb2d45fe48fd86/image-8.jpg
And we're done with this topic! Well Done!
Drafted by Alyssa (Biology)