Apical dominance is the phenomenon in which the main central stem of a plant grows more strongly than its side branches. This happens because the apical bud (the tip of the main shoot) suppresses the growth of lateral (side) buds below it.
How it works:
- The apical bud produces a plant hormone called auxin.
- Auxin moves downward from the shoot tip and inhibits the growth of lateral buds.
- As a result, the plant focuses its energy on upward growth (elongating the main stem) instead of growing side branches.
Relation to vegetative growth:
- Promotes height growth:
- Apical dominance helps the plant grow taller to reach more sunlight during vegetative growth.
- Controls branching:
- It ensures that the plant grows in a vertical direction rather than becoming too bushy early on.
- Can be modified:
- When the apical bud is removed (for example, by pruning or pinching), the flow of auxin stops.
- This allows lateral buds to grow and produce more branches and leaves, increasing the plant’s vegetative spread and potential for higher yield.
In simple terms:
Apical dominance is the control of side branch growth by the top bud. It helps the plant grow taller, but gardeners and farmers can manage it to make plants bushier and more productive during vegetative growth.