Influence of cutting type and size on rooting of Lavandula dentata L

Even though the Lavandula species may be propagated by seeds, it should not be the preferred propagation method because it causes a great lack of uniformity. On the other hand, asexually propagated lavender crops would provide more homogeneous crops, and clones from high quality plant material would increase the odds for obtaining a higher quality essential oil. However, problems such as poor rooting and restrict market availability for superior clones have been a problem in vegetative propagation of the Lavandula species. The objective of this work was to define which type and size of cutting is more adequate for cutting propagation of L. dentata, a very productive Lavandula species. Cuttings with 5, 8, 10 or 13 cm and from the apical or basal parts of stems cut from L. dentata stock plants were placed in Plantmax HT® filled polystyrene foam trays and kept under intermittent mist system for two months. Averages of root number, length of the longest root, fresh and dry root weight, and percentage of rooting were evaluated. Apical cuttings combined 97.9% rooting with an average of 13.2 roots per cutting and basal cuttings 93.7% rooting with 2.98 roots per cutting. Apical cuttings with at least 10 cm in length were considered the most adequate for cutting propagation of L. dentata.