I was trying to find a relationship between IBA and kelp and I've found
this article.
It seems kelp is rich in Cytokinins (CK) that promotes cell division in new shoots and it counteracts the effects of auxins (in this case IBA).
So, it seems IBA is more effective in root growing while CK in new shoots.
The use of one or the other depends on the plant's development stage.
So, my question...why is kelp used in root growing promotion? Where's the relation with the auxins?