ENRAIZAMENTO DE MINIESTACAS E PRODUTIVIDADE DE MINICEPAS DE CEDRO AUSTRALIANO MANEJADAS EM CANALET 5ES E TUBETES

Abstract

The planted forest stands aim to supply the growing demand for wood, especially for the sawing and veneer industries, that exclusively used wood from native forests. The Australian cedar ( Toona ciliata ) belongs to the family Meliaceae, is the species of interest for this sector. Studies with the Australian cedar propagation have carried out in latest years, mainly involving the use of mini-cuttings due to the need for high quality cuttings. The objectives of this paper were to evaluate the rooting and the productive capacity of Australian cedar mini-strains, managed in lifted seedbeds and 180 cm3 plastic tubes systems. So, two mini-clone gardens were set up. The mini-strains of both gardens were grown from cut-off seedlings originated from seeds. Successive collections of sprouts were carried out to get the mini-cuttings. Afterwards, they remained in the rooting area under intermittent mist. Thirty days later the rooting characteristics of the cuttings originated from both mini-gardens were evaluated. The period of permanence of the cuttings in the gardens was seven-month long. During this period, six collections from the lifted seedbed and four from the plastic tubes were carried out. The mini-strains in the two systems showed 100 % of survival rate. At the end of this seven-month period, an increasing tendency of the average number of mini-cutting was found out in both systems. Those from the lifted seedbed showed more productivity than those ones from the tubes. The plants from the mini-cuttings of the tube showed higher number and length of adventitious roots at the end rooting stage.Os povoamentos florestais plantados buscam atender \ue0 demanda crescente por madeira, principalmente, para as ind\ufastrias de serraria e de lamina\ue7\ue3o, que utilizavam madeira exclusivamente de matas nativas. O cedro australiano ( Toona ciliata ), pertencente \ue0 fam\uedlia Meliaceae, \ue9 uma das esp\ue9cies de interesse desse setor. Pela necessidade cada vez maior por mudas de alta qualidade, estudos sobre propaga\ue7\ue3o de cedro australiano t\ueam sido realizados nos \ufaltimos anos, principalmente envolvendo o uso da miniestaquia. Os objetivos deste trabalho foram avaliar o enraizamento e a capacidade produtiva das minicepas de cedro australiano, manejadas em sistemas de canalet\uf5es e em tubetes de 180 cm3. Assim, estabeleceram-se dois minijardins de minicepas formadas a partir de mudas recepadas, produzidas por sementes. Nestes dois sistemas, foram realizadas coletas sucessivas de brota\ue7\uf5es para confec\ue7\ue3o de miniestacas, que permaneceram por 30 dias no setor de enraizamento, em c\ue2mara com nebuliza\ue7\ue3o intermitente. Ap\uf3s este per\uedodo, foram avaliadas as caracter\uedsticas do enraizamento das mudas originadas nos dois sistemas de minijardins testados, que foram conduzidos por sete meses e, durante este per\uedodo, foram realizadas seis coletas no minijardim de canalet\ue3o e quatro, no de tubetes. As minicepas dos dois sistemas apresentam 100 % de sobreviv\ueancia. Ao final do per\uedodo observou-se tend\ueancia no aumento do n\ufamero m\ue9dio de miniestacas em ambos os sistemas. As minicepas do sistema de minijardim em canalet\ue3o s\ue3o mais produtivas que as do sistema conduzido em tubetes. As mudas originadas de miniestacas do sistema de tubetes apresentam maior n\ufamero e comprimento de ra\uedzes advent\uedcias na expedi\ue7\ue3o do setor de enraizamento