Auxins

• Auxins:

  • Useful for controlling plant growth. Used for:

  1. Killing weeds

  • Most weeds growing in fields of crops or in a lawn are broad- leaved in contrast to grasses which have narrow leaves
  • Selective weedkillers have been developed using auxins, which only affect the broad- leaved plants
  • This disrupts their normal growth patterns, which soon kills them, whilst leaving the grass and crops untouched
• 2. Growing from cuttings with rooting powder

  • A cutting is a part of a plant that has been cut off it
  • If you stick cuttings in the soil they won't grow, but if you add rooting powder, which contains auxins, they will produce roots rapidly and start growing as new plants
  • This enables growers to produce lots of clones (exact copies) of a really good plant very quickly
• 3. Growing cells in tissue culture

  • Tissue culture can be used to grow clones of a plant from a few of it's cells
  • To do this, hormones such a auxins needed to be added to the growth medium along with nutrients to stimulate the cells to divide to form roots and shoots