Effect of plant growth regulators in the rooting of Pinus cuttings

This work evaluated the rooting of Pinus caribaea var. hondurensis Morelet cuttings under the action of different levels of plant growth regulators. The cuttings consisted of 4-6 cm long shoots of P. caribaea var. hondurensis Morelet with their basal needles removed. The basal part of the cuttings were treated for 2 seconds with the following treatments: 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. After receiving the treatment, the cuttings were planted in tubes containing 50% carbonized rice hulls and 50% vermiculite. The evaluations, performed 60 days after planting, showed that P. caribaea var. hondurensis cuttings treated with IBA produced a higher percentage of rooted cuttings than those treated with NAA; the most effective treatment was IBA 4000mg L-1 plus 100mg L-1 paclobutrazol.O trabalho avaliou o enraizamento de estacas de Pinus caribaea var. hondurensis Morelet sob a ação de diferentes níveis de reguladores vegetais. As estacas foram feitas de brotações de 4 a 6cm de comprimento de mudas de P. caribaea var. hondurensis Morelet com corte bisel na base sendo as acículas basais eliminadas. A base das estacas foram submetidas aos tratamentos por 2 segundos com os seguintes tratamentos: 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 e testemunha. Após os tratamentos as estacas foram plantadas em tubetes contendo 50% de palha de arroz carbonizada e 50% de vermiculita. As avaliações realizadas aos 60 dias após o plantio mostraram que estacas de P. caribaea tratadas com IBA levaram a maior porcentagem de estacas enraizadas que aquelas tratadas com NAA, sendo o mais efetivo, IBA a 4000mg L-1 em conjunto com 100mg L-1 de paclobutrazol