It's the same chemical sealed fruits, mainly bananas give off. I've used it a time or two when I had a plant(s) go hermie on me. I've even been thinking about using it on seed runs with funny style plants like the Chems and OGs, etc.
This is a hormone that has really proven itself many times for me, much more obvious effect than the other PGRs and safer as well!
I usually only use it if I see any balls in early flower, some strains are prone to it. I use 400pm florel ph'd to 4.0-4.5 and foliar sprayed once at day ~15 if I see any balls/brown pistils and then again a week later at day ~21 to make sure.
Ethephon has the following very obvious and significant effects:
- reduced internode space and shorter plants after flip (plants stop stretching around day ~17 instead of day ~22). This is perhaps to most significant effects since it leads to much denser bud structures. I'll be able to report a rough yield impact soon.
- earlier bud maturation. The buds start more dense and solid. Instead of being airy and then "filling in," they start dense and expand out.
- Earlier terpene production. My room smells like day 50 at day 20.
- Some premature leaf yellowing (on older shade leaves). This is a side affect of the hormonal ripening response.
- Early and strong coloration
- Suppression of any seeds and nanners. Lifesaver if using an unstable strain.
Overall this is a powerful hormone that I feel is an indispensable tool for an indoor cultivator.
I'll do my best to update with thread with any concrete data as I collect it.