Pinus caribaea var. hondurensis Morelet shoots
were collected from a clonal garden. The cuttings
were 4 to 6cm in length with the basal needles
eliminated. Later, the cuttings were treated with
plant growth regulators, planted in tubes and taken
to a intermitent mist system in a enclosed
polyethylene propagation house for 60 days. The
cuttings were treated with two auxins, indole-3-
butyric acid (IBA) and α-naphthalene acetic acid
(NAA), and with paclobutrazol (PBZ), by
immersing the base of the cuttings in a gel solution
for 2 seconds. The following treatments were
used: 1- NAA 2000mg L-1; 2- NAA 4000mg L-1;
3- NAA 6000mg L-1; 4- NAA 2000mg L-1 + PBZ
100mg L-1; 5- NAA 4000mg L-1 + PBZ; 6- NAA
6000mg L-1 + PBZ; 7- IBA 2000mg L-1; 8- IBA
4000mg L-1; 9- IBA 6000mg L-1; 10- IBA 2000mg
L
-1 + PBZ; 11- IBA 4000mg L-1 + PBZ; 12- IBA
6000mg L-1 + PBZ; and a control.
Effect of Plant Growth Regulators in the Rooting of Pinus Cuttings
Brazilian Archives of Biology and Technology
191
After treatment, the cuttings were planted in tubes
containing 50% carbonized rice hulls and 50%
vermiculite. Evaluations were performed 60 days
after planting, including: rooting percentage, total
sugars contents, reducing sugars contents and
phenol contents. The biochemical analyses were
conducted with cutting samples on the day the
experiment was started and at the end of the
experiment. The total phenol content analysis in P.
caribaea var. hondurensis cuttings was performed
according to the official method prescribed by the
Association of Official Analytical Chemists -
A.O.A.C. (1984), adapted by Skorupa et al.
(1998). The total sugars and reducing sugars
analyses were performed by the Somogy-Nelson
method (Nelson, 1944).
The experiment was carried out as a completely
randomized design with 13 treatments containing
4 replicates with 8 cuttings each. The data were
submitted to analysis of variance (F test) and the
means compared by Tukey test at the 5%
probability level. The data were transformed into
arc sin sqrt((x + 0.5)/100) for statistical analysis.