CUTTINGS PROPAGATION OF JARRAH FOREST PLANTS WITH ORNAMENTAL PROSPECTS: THREE PROTEACEAE AND FIVE NON-PROTEACEAE SPECIES COMPARED

A series of cuttings experiments and production investigations were completed for eight Jarrah forest species with ornamental, landscaping, revegetation and mine rehabilitation values. The effect of two alcohol based IBA dips on cuttings root production was compared with soaking cuttings in an IBA and NAA solution (Banksia dallanneyi, Hibbertia acerosa, Lasiopetalum cardiophyllum, Leptomeria cunninghamii and Leucopogon capitellatus). Either one or the other of the alcohol based IBA dips was superior for all species except the sole Proteaceae species tested (B. dallanneyi); which had its best performance with the water-based control. In a Lechenaultia biloba experiment comparing three alcohol-based IBA dips with two talc-powder-based dips the alcohol-based IBA dips did not produce higher cuttings root production. Foliar applications of IBA, vitamins, 2,4-D and fertiliser all had negative effects on rooting and survival of Adenanthos barbiger cuttings. In large scale production A. barbiger cuttings performance varied widely between production seasons whereas L. biloba had a narrower performance range. Lechenaultia biloba was successfully added to commercial production; with 230,153 plants produced from 1999 to 2014 and planted in Alcoa Mining’s bauxite mine rehabilitation. Two of the three Proteaceae species investigated were not suitable for mass propagation by cuttings. Only 6% of B. dallanneyi cuttings produced roots on the best treatment and less than 1% of Persoonia longifolia cuttings grew roots in any treatment. The third Proteaceae species (Adenanthos barbiger) was capable of large scale cuttings production; with 201,576 plants produced from 1999 to 2014 and planted in Alcoa’s mine rehabilitation. The highly variable rooting between crops was considered to be mostly due to the use of wild collected cuttings. Developing stock plants in pots could reduce this variation and reduce the need to harvest wild populations.