Plant Hormones (Auxins):

• Produced at the tips of shoots or roots.
• Effects of Auxins:
  • On Stems: Promotes more rapid growth in the region just below the shoot tip and decreases down the stem.
  • On Leaves: Retains leaves on the plant, inhibits early abscission.
  • On Roots: Stimulates root development at low concentrations and inhibits at high concentrations.
  • On Fruits: Promotes fruit development.

Importance of Auxins:

• Cell Division: Promotes growth.
• Apical Dominance: Inhibits side branch growth.
• Root Growth: Stimulates development of adventitious and lateral roots.
• Cell Expansion: Facilitates elongation in the zone of cell elongation.

Practical Uses of Plant Hormones:

1. Synthetic auxins are used as weed killers.
2. Synthetic hormones promote rapid root growth in stem cuttings.
3. Helps in managing apical dominance.
4. Prevents premature fruit drop.