Plant growth regulators (auxin & cytokinin) | Tree Biology

Plant growth regulators, aka plant hormones, are chemicals that act as signals for growth. They're more accurately called growth regulators since they can both stimulate and inhibit growth.
There are 5 traditional classes of PGRs:
1. Auxin is likely the most well known, and it affects multiple areas of growth (leaf & flower formation, suppresses lateral buds, initiate roots). For arborists, this comes into play with heading cuts or topping trees - once the tip/top is removed, auxin is interrupted, and lateral buds can grow out.
2. Cytokinins are important in cell division (aka cytokinesis).
3-5. Giberellins, abscisic acid, and ethylene will be covered in a bonus video since they aren't included in the certification guide.

[@grant9047]

good job

[@arboriststudyguide]

Thanks Grant!!! for commenting on every video!

[@arboriststudyguide]

by the way - do you have your exam scheduled? when are you planning to go for it?

[@grant9047]

@@arboriststudyguideyes it’s scheduled for June 8th

[@arboriststudyguide]

@@grant9047 dang that's coming up! good luck with that, let me know how it goes

[@grant9047]

@@arboriststudyguide passed the exam today, got a 78% so I passed it by 2 % but a pass is a pass lol

[@ceebee9605]

"...a tomato plant..." 💀💀💀💀

[@arboriststudyguide]

@@ceebee9605 oh yea I didn't have one of those so I had to substitute 😂 but that's where I first heard the advice - for tomato growing

[@ceebee9605]

@@arboriststudyguide loved it so much!!! haha! 🤣🤣 great vid

[@arboriststudyguide]

@@ceebee9605 thanks! Glad to hear it 😊