DEVELOPING INFLORESCENCES OF PROTEA ‘CARNIVAL’ REDUCE THE RESPONSIVENESS OF NON-FLOWERING SHOOTS TO BENZYLADENINE INDUCTION OF FLOWERS “OUT OF SEASON”

The responsiveness of non-flowering shoots on eight and 12-year old plants of Protea ‘Carnival’ in terms of budbreak and flowering incidence following a 500 mg·L^-1 benzyladenine (BA) application (ABG-3062; active ingredient: BA 2% w/w), eight months after pruning in April 2003, was compared to that of shoots subject to BA treatment as MaxCel^TM (active ingredients: BA 1.9% w/w) at either 500, 1000 or 2000 mg·L^-1 on the same plants, 20 months after pruning.
Plants treated in April 2004 differed from the April 2003 treatment in that developing inflorescences were present on the plants in 2004. BA application enhanced budbreak in all shoots, irrespective of plant age, BA concentration or treatment year.
For both age groups of plants more shoots initiated an inflorescence when treated with BA eight months after pruning as compared to shoots treated 20 months after pruning.
The quality of shoots treated 20 months after pruning were comparable or better than shoots treated eight months after pruning.
Apparently the presence of developing inflorescences on the same plant when non-flowering shoots in autumn are treated with BA reduces the probability of flower initiation taking place.

XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on Advances in Ornamentals, Landscape and Urban Horticulture

E.W. Hoffman, G.J. Jacobs

https://doi.org/10.17660/ActaHortic.2012.937.95