EFFECT OF THE TIME INTERVAL BETWEEN COLLECTION/PREPARATION AND PLANTATION ON THE ROOTING OF MINICUTTINGS OF Eucalyptus urophylla x Eucalyptus grandis CLONES

Abstract

O objetivo deste trabalho foi avaliar o efeito do intervalo de tempo entre coleta/preparo e estaqueamento no enraizamento de miniestacas em quatro clones de Eucalyptus urophylla x Eucalyptus grandis . O delineamento experimental utilizado foi o inteiramente casualizado, arranjo bifatorial com parcelas subdivididas, tendo os intervalos de tempo nas parcelas (0, 2 e 4 horas) e clones nas subparcelas (C1, C2, C3 e C4), em tr\ueas repeti\ue7\uf5es de 192 plantas cada. Avaliou-se o enraizamento e a sobreviv\ueancia de miniestacas na sa\uedda da casa de vegeta\ue7\ue3o e casa de sombra, a sobreviv\ueancia, o crescimento e a qualidade do sistema radicular de mudas aos 50 dias de idade. Em tr\ueas dos quatro clones estudados, per\uedodos de armazenamento das miniestacas superiores a 2 horas causam redu\ue7\ue3o significativa no percentual de enraizamento e na sobreviv\ueancia das mudas aos 50 dias de idade. No entanto, o clone C2 apresenta a m\ue1xima efici\ueancia t\ue9cnica para enraizamento na sa\uedda da casa de sombra e para sobreviv\ueancia das mudas aos 50 dias, quando suas miniestacas s\ue3o armazenadas por, respectivamente, 2,3 e 2,5 horas; assim como apresenta maior crescimento em altura, quando armazenadas por 4 horas. Em todos os clones, mudas provenientes de miniestacas armazenadas por 4 horas apresentam qualidade do sistema radicular inferior ao sistema radicular de mudas obtidas a partir de miniestacas com 0 e 2 horas de armazenamento.This study aimed to assess the effects of the time interval between the collection/preparation and plantation on the rooting of minicuttings of four Eucalyptus urophylla x Eucalyptus grandis clones. The experimental design used was entirely randomized, bi-factorial and arranged with sub-divided plots, being time intervals in plots (0, 2 and 4 hours) and the clones in subplots (C1, C2, C3 and C4), with three replications of 192 plants each. The rooting and the survival of minicuttings in the greenhouse exit and in the shade house, the survival, the growth and the root system quality of 50-day-old seedlings were assessed. Among the four clones studied, it was observed, in three ones, that storage periods of the minicuttings above two hours caused significant reduction in the percentage of rooting and in the survival of 50-day-old seedlings. However, the clone C2 presents the most efficient technique for rooting in the shade house exit and the survival of 50-day-old seedlings when their minicuttings are stored for 2.3 and 2.5 hours, respectively; as much as it presents greater height growth, when the minicuttings were stored during 4 hours. In all clones, those seedlings from minicuttings stored during 4 hours present lower quality of root system than plants obtained from cuttings with 0 and 2 hours of storage