Rooting of Prosopis alba mini-cuttings

Mesquite (Prosopis alba Grisebach), an important species in arid and semiarid regions, is currently commercially propagated by seeds and so there is great interest in developing techniques for species propagation, domestication and improvement. Cloning through mini-cuttings is a new and promising technique for the production of clonal seedlings of forest species. The main objective of this work was to evaluate vegetative propagation using the mini-cutting technique and indolebutyric acid (IBA) at different concentrations (0, 3,000, 4,500, 6,000 and 7,500 mg L⁻¹) on rooting of P. alba clones. Rooting was achieved in 98–100 % of the mini-cuttings at all concentrations tested. Increasing IBA concentration resulted in an increase in the number of leaves and leaflets, as well as in fresh matter weight and number and length of roots of clone seedlings, until an optimum point (between 3480 and 4800 mg L⁻¹) was reached. Plants were also vegetatively propagated in the field via conventional clonal garden cuttings under the same rooting conditions to compare the efficiency of the two propagation techniques. Mini-cuttings showed higher rooting and survival percentages than cuttings. A correlation analysis conducted between characteristics of stock plants (height, diameter, number of shoots) and shoots (height, diameter) showed a positive correlation between rooting and height of shoots with total root length, leaflet number, and height of clonal seedlings. We propose the mini-cutting technique as a tool for P. alba cloning.