Avaliação da produtividade da Acacia mearnsii De Wild. (Acácia negra) em função de diferentes espaçamentos

Abstract

The black wattle (Acacia mearnsii De Wild.), it is constituted on second main forest essence planted in Rio Grande do Sul, just losing for the Eucalyptus. The culture of that species is of fundamental importance for the tannin industries, foils and cellulose in the state, front to the good results economical coming of the exploration of the same, because the peel is sold for the extraction of tannins and the wood is marketed for conversion in cellulose, foils and energy. The black wattle has been considered as one of the main planting alternatives in the agricultural area of the state. In the present work, it was studied the productivity of the Acacia mearnsii De Wild. (black wattle) in function of different spacings, with initial base of one thousand hundred sixty trees, distributed in five treatments and three repetitions, originated of research developed jointly among the Empresa SETA (Sociedade Extrativa de Tanino de Acácia Ltda.) and the Centro de Pesquisas Florestais (Cepef) of Universidade Federal de Santa Maria (Santa Maria-RS), in the district of Capão Comprido belonging to the municipal district of Butiá-RS, in area of the company. The company uses a spacing of 3,0 m x 1,33 m in their plantings, for accomplishing them with machine, however the results obtained in the test d.m.s. they point that for the united analysis of the treatments analyzed in the period from 2002 to 2004, the volumetric average of the treatment 5 differs statisticaly of all the other ones; the treatments 1, 4 and 3 don't differ statisticaly amongst themselves and the treatment 2 differs statisticaly of all the other ones at the level of significance of 5%, being concluded the treatment 5 as soon as (3,0 m x 2,50 m) it is the most suitable for the planting of the black wattle (Acacia mearnsii De Wild.), tends in view the largest volumetric average. In the aspect regarding the analyzed period, the results obtained in the test d.m.s. they appear that so much for the analysis individual as united of the treatments, the three years-old volumetric averages differ statisticaly amongst themselves at the level of significance of 5%, and the year of 2004 in all of the treatments presented the largest volumetric average