Re: Are auxins useful to cause plants to bloom?

Yes, at least in part.
No one knows exactly what makes plants to bloom. It seems to be a balance 
between different hormones (specially auxin and citokinin) more than just a 
single hormone. It helps to give a burst of auxin but it may not work with 
every plant. Each plant seems to have particular condition for flowering 
and no such thing as a "florigen" has been characterised, despite the 
intensive search. To apply hormone to the leaves may work, but one cannot 
control the exact dosage that enters in the plant. You basically have to 
try every possibility.
Imagine if we could control the production of flowers. We would be able to 
control the production of corn, beans, rice... The economic potential of 
this is enormous, but no one has manage to do that.
Bye,
Marco.