THE INFLUENCE OF GENOTYPE, TERMINALITY AND AUXIN FORMULATION ON THE ROOTING OF LEUCOSPERMUM CUTTINGS.

Terminal and subterminal semi-hardwood cuttings of six clones of Leucospermum cordifolium and some Leucospermum hybrids were rooted in Autumn, with and without bottom heat and mist irrigation, at 23,0 ± 0,8 °C and 12,7 ± 2,0 °C respectively.
IBA in four formulations was applied as a basal dip at concentrations of 5 g l^-1 solution or 10 g kg^-1 powder.
Genotype and temperature influenced rooting percentage the strongest and interacted strongly with each other as well.
Rooting temperature also interacted with the other two factors.
Terminal cuttings rooted consistently better at the higher but not at the lower temperature.
Auxins had little effect on rooting percentages at the higher, but influenced rooting strongly at the lower temperature.
At the lower temperature 10 g kg^-1 IBA powder increased mean rooting percentage significantly above 5 g l^-1 IBA in 50% ethanol alone or combined with NAA and ethephon.
It was concluded that a knowledge of the temperature requirements of individual Leucos permum cultivars is required when using unheated rooting frames.
Economizing applications are discussed.

I International Protea Research Symposium

G.J. Brits

https://doi.org/10.17660/ActaHortic.1986.185.2