Training & Plant Architecture
Apical Dominance & Topping
The shoot apex influences lateral growth through interacting hormonal and resource signals. Removing it changes branch competition but does not guarantee a fixed number of replacement tops.
Key concepts
- Axillary buds already exist at nodes
- Removing the shoot apex changes hormonal relationships and resource distribution
- Plant response depends on genotype, stage, health, and environment
- Cuts create wounds that require recovery
What to measure or observe
- Record node number at topping
- Track which axillary shoots accelerate afterward
- Inspect wound closure and stem support
- Compare canopy height distribution before and after
Common mistakes
- Describing auxin as a simple on/off switch
- Topping severely stressed plants
- Assuming topping automatically increases yield
Visuals this lesson still needs
- Apical dominance flow diagram
- Topping cut-location sequence
- Axillary response timeline
- Intact-versus-topped architecture