A chemical substance that controls the growth and development of a cannabis plant – root-inducing hormones help the clones root.
Merriam-Webster Online Dictionary
hormone (noun)1.
a product of living cells that circulates in body fluids (as blood) or sap and produces a specific often stimulatory effect on the activity of cells usually remote from its point of origin , also a synthetic substance that acts like a hormone
2.
- sex hormone
Controller, overseer, supervisor, coordinator, intermediary, envoy, courier, transmitter, indicator, cue, prompt, trigger, instigator, accelerator, facilitator, influencer, adjuster, tuner, balancer