Influence of cutting position and rooting media on rhizogenesis in oleander cuttings

Improvement in rooting of native Nerium oleander L. cuttings can considerably enhance nursery production. The effect of rooting medium (sand, perlite A13, vermiculite M2, vermiculite M3 and cocopeat) and the position of the stem (apical, central and basal) from which the cutting is taken on the rooting quality of native oleander from SE Spain was studied. The following root parameters were measured: Percentage of rooting; No. of roots per cutting; Root Distribution Index (RDI); The number of forks per cutting; Total root length and Root dry weight. The results showed that both the medium and position of cutting significantly modified all the parameters studied. This interaction suggests that the choice of medium depends on the position from which the cutting was taken and vice versa. Both vermiculites and the cocopeat favoured rhizogenesis, while the other two substrates seemed unsuitable for oleander rooting. In general, basal cutting produced the larger root growth, although the longer number of roots and the higher homogeneity in their distribution was obtained with apical cuttings.