Lavender plants (Lavandula angustifolia) are commonly propagated in commercial nurseries by taking cuttings to produce new, cloned crops.
Describe how to clone a lavender plant by taking a stem cutting.
A grower wanted to find out whether liquid rooting hormone A or powder rooting hormone B is more effective at promoting root development. The grower treated one cutting with hormone A and one cutting with hormone B before planting them in identical, sterilized compost. Both cuttings were kept under the same light intensity and temperature.
After 6 weeks, the grower carefully washed away the compost and measured the dry mass of roots produced by each cutting:
The grower concluded that hormone A is more effective. A student commented that, although the experiment was valid, the single-replicate design means the results do not strongly support this conclusion.
Describe and explain how the grower could improve this investigation to have more confidence in the conclusion.
State three advantages of vegetative propagation (cloning) compared to growing plants from seeds in commercial horticulture.
