Potencial de enraizamento de estacas lenhosas de espÃcies florestais da mata ciliar / Potential for rooting of wood cutting species from riparian forest

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

The bioengineering has been used for the containment of slopes and ravines on the banks of watercourses. One of its tools is the use of hardwood cuttings planted directly in the field, but this requires that species have local adaptation with large capacity for rooting. Thus, this study had the objective of study the propagation by cuttings of native woody forest species aiming the use in bioengineering techniques. Therefore, three separate experiments were performed. In the first experiment, cuttings obtained from nine species, with lengths ranging from 15 to 20 cm were made in the diameter classes: 1) 3.0 - 6.9 mm 2) 7.0 - 10.9 mm 3) 11 , 0 to 17.9 mm and 4) 18.0 - 30 mm, which consisted in treatment. The cuttings were planted in plastic tubes of 280 cm3 filled with vermiculite, carbonized rice husk (1:1). Completely randomized experimental arrangement was used with five replicates of ten cuttings per treatment. The rooting occurred in the greenhouse at nursery facilities belonging to the Federal University of Lavras. After 45 days were evaluated: the percentage of rooted cuttings, the number of roots (NR) and the length of the longest root (CMR). For the second experiment, cuttings of 20 species were made in the class of diameter 3, referring to the first experiment. The treatments consisted of application of IBA (IBA) on the base of the cuttings, in concentrations of 0.0, 0.5, 1.0 and 1.5 mM. The procedures used in the planting, management, environment and time of rooting, and experimental apparatus and evaluation were identical to those described in the first experiment. In the third experiment were evaluated anatomical barriers in cuttings of two species that showed high percentage of rooting, two with low percentage of rooting and not embedded in the two previous experiments. The cuttings were made at four diameter classes already described, which consisted in treatment. Sections were removed from 2 cm in length and the cutting transverse sections made with the aid of the microtome table, which were stained with safrablau 1%, for preparation of semi permanent slides. Through observation of the slides, photomicrographs were obtained with the aid of a digital camera coupled to an optical microscope. We evaluated the occurrence and distribution of sclerenchyma in the cortex of the species studied, counted the number of layers and measured the total thickness of them. In the first experiment, the nine species studied, six had rates that ranged from two roots to 88% while cuttings with diameters ranging between 11.0 and 17.9 mm had better results on rooting and quality of the root system. For the second experiment, there was no influence of the concentrations of IBA on the characteristics used for rooting. For the analysis of cross-sections of the cuttings, anatomical barriers have been identified in species, not embedded in a species with a low percentage of rooting, while the species with high percentage of rooting showed no anatomical barrier.

ASSUNTO(S)

bioengineering recursos florestais e engenharia florestal hardwood cuttings bioengenharia vegetative propagation estacas lenhosas propagaÃÃo vegetativa

ACESSO AO ARTIGO

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