With reference to phenological stages duration
and growth, variable effects have been reported in the literature, particularly
with PBZ. The application of PBZ markedly delayed floral initiation in
sunflower and this effect was dependent on plant age (Almeida and Pereira
1996). On the contrary, PBZ foliar applications (up to 80 mg/L) for the
control of height in potted sunflower had little effect on growth and
flowering responses of the plants (Whipker and Dasoju, 1998).