Resgate vegetativo e propagação de cedro-australiano por estaquia

Abstract

Resumo -O objetivo deste trabalho foi avaliar métodos de resgate vegetativo para a produção de estacas (corte raso, anelamento total e semianelamento) de árvores adultas de cedro-australiano (Toona ciliata var. australis). Avaliou-se o número de brotos produzidos aos 60, 120 e 180 dias, bem como a correlação entre o diâmetro médio do tronco à altura do peito (DAP) e o número de brotos. Com as brotações resultantes de cada método, produziram-se estacas que foram submetidas à retirada e ao corte de folíolos, e então receberam a aplicação de ácido indolbutírico (AIB) (0 e 6.000 mg L -1 ). Avaliou-se a influência dos fatores método de resgate, tempo de coleta, número de folíolos das estacas e planta matriz, em presença e ausência de AIB, na sobrevivência e no enraizamento das estacas. Não houve correlação entre o DAP das árvores e o número de brotações. O corte raso aos 120 dias proporcionou a maior produção de brotos (15,31). Estacas obtidas do semianelamento apresentaram maior sobrevivência (57,8%) e enraizamento (55,5%). Estacas com dois pares de folíolos inteiros e tratadas com 6.000 mg L -1 de AIB apresentaram maior sobrevivência (65,5%) e enraizamento (56,7%). Houve grande variação na sobrevivência e no enraizamento entre plantas matrizes. O resgate vegetativo e a estaquia apresentam potencial para multiplicação clonal de árvores adultas de cedro-australiano.Termos para indexação: Toona ciliata, enraizamento, propagação assexuada, propagação vegetativa, silvicultura clonal. Vegetative rescue and propagation of Australian red cedar by cuttingsAbstract -The objective of this work was to evaluate vegetative rescue methods for the production of cuttings (clearcutting, full annealing, and half-annealing) of red cedar (Toona ciliata var. australis) mature trees. The number of produced shoots was evaluated at 60, 120 and 180 days, as well as the correlation between stem mean diameter at breast height (DBH) and the number of sprouts. From the resulting sprouts of each method, cuttings were produced and subjected to cutting and removal of leaflets, and then received the application of indolbutyric acid (IBA) (0 and 6,000 mg L -1 ). Evaluations were made for the influence of the following factors on plant survival and rooting: rescue method, collection time, number of leaflets of cuttings, and matrix tree, in the presence and absence of IBA. There was no correlation between the DBH of trees and the number of produced shoots. Clearcutting at 120 days provided the highest increase of shoots (15.31). Cuttings obtained from half-annealing had higher survival (57.8%) and rooting (55.5%) rates. Cuttings with two pairs of preserved leaflets and treated with 6,000 mg L -1 IBA showed higher rates of survival (65.5%) and rooting (56.7%). There was wide variation in survival and rooting capacity among matrix trees. The vegetative rescue and propagation by cuttings have potential for clonal multiplication of Australian red cedar mature trees.

EPICORMIC SHOOTS INDUCTION AND ROOTING CUTTINGS OF Calophyllum brasiliense

“…The low efficiency of partial girdling in epicormic shoots induction was also observed in Toona ciliata plants. On the other hand, the cuttings produced from the above mentioned technique had evidenced a high rooting cuttings percentage (PEREIRA et al, 2015).…”

“…Among these, coppicing has shown greater effi cacy in terms of vegetative rescue in Ilex paraguariensis (WENDLING et al, 2013;STUEPP et al, 2015a;, Araucaria angustifolia (WENDLING et al, 2009), Anadenanthera macrocarpa (DIAS et al, 2015) and Toona ciliata (PEREIRA et al, 2015).…”

“…Several studies have evaluated the effect of different genotypes in the adventitious rooting of plant propagules (OLIVEIRA et al, 2012;PEREIRA et al, 2015). Additionally, in Calophyllum brasiliense species, it was observed a high genetic variability regarding progenies and clones on cuttings rooting (CIRIELLO, 2010).…”

“…Several studies have mentioned the importance of using juvenile propagules in propagation of forest species (WENDLING et al, 2013;PEREIRA et al, 2015;STUEPP et al, 2015b).…”

“…However, such method is highly dependent on the regrowth of mother plants capacity and, in certain cases, it turns to be unfeasible due to low vigor. In such cases, the use of techniques such as girdling and partial girdling are recommended, not damaging the plant survival (PEREIRA et al, 2015;DIAS et al, 2015;STUEPP et al, 2015a).…”