GA3 or cytokinins delayed leaf yellowing in cut stock flowers
(Ferrante et al., 2008) and cut tulip flowers (van Doorn et al., 2011),
but leaf yellowing in these species was more delayed by cytokinins
than by GA3. The effects of these hormones on petal blackening
in lotus are also similar to their effect on Iris tepal senescence.
Cytokinins and GA3 delayed Iris tepal senescence by the same
amount of time when applied at the time of harvest, i.e. before
bud opening (van Doorn, unpublished data).