ROOTING OF Pinus patula CUTTINGS

Abstract

Pinus patula Schiede ex Schltdl. et Cham. is an endemic pine in México, broadly used for commercial plantings in several countries. Massive propagation of improved individuals of this species through rooted cuttings provides the opportunity to increase and homogenize its productivity. The effect of substrate (perlite vs. mix of peat-moss with vermiculite), donor plant age (12, 18 and 24 months of age) and indole butyric acid (IBA) dose (0, 5000 and 10 000 ppm) (i.e., mg L^-1) on rooting of P. patula cuttings was evaluated using a factorial layout in a complete random blocks experimental design. Survival, rooting, number and length of primary roots, presence of secondary roots and callus development were evaluated after 14 weeks. Rooting percentage (21.4 vs. 14.7 %), as well as IBA dose and donor plant age effects on cuttings response were higher in the perlite substrate. Rooting capacity was reduced almost in half (29.2 to 15.8 %) when donor plant age increased from 12 to 24 months. IBA inhibited rooting in the youngest cuttings, but not in the oldest ones. Control of factors evaluated allowed to reach over 50 % of rooted cuttings in one treatment combination, an acceptable value for an operational cloning program.