African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6576

Full Length Research Paper

Artificial form factor equations for Tectona grandis in different spacings

Felipe Vieira da Cunha Neto
  • Felipe Vieira da Cunha Neto
  • Department of Forestry Engineering, Institute Federal of Mato Grosso (IFMT), Cáceres Campus, Cáceres, Mato Grosso, Brazil.
  • Google Scholar
Diogo Guido Streck Vendruscolo
  • Diogo Guido Streck Vendruscolo
  • Department of Forestry Engineering, Federal University of Mato Grosso (UFMT), Cuiabá Campus, Cuiabá, Mato Grosso, Brazil.
  • Google Scholar
Ronaldo Drescher
  • Ronaldo Drescher
  • Department of Forestry Engineering, Federal University of Mato Grosso (UFMT), Cuiabá Campus, Cuiabá, Mato Grosso, Brazil.
  • Google Scholar


  •  Received: 29 June 2016
  •  Accepted: 17 August 2016
  •  Published: 15 September 2016

Abstract

The use of form factors is a practical alternative for estimating tree volume. However, only a few studies in this topic are relevant to Tectona grandis, and only few to those that evaluate the effect of spacing on it. The goal of this study was to generate form factor equations and evaluate spacing influence on it in teak plantations. Samples were taking in 3 × 2 m, 4 × 3 m, 5 × 2 m, and 6 × 2 m plots. The database consisted of rigorous cubage of 120 trees, 30 of which were utilised in spacing for the calculation of the artificial form factor models; these were compared using statistical indicators and graphic analyses. In order to assess possible differences among the equations, the identity test of models at the p < 0.05 significance level was utilised. The results of the identity test of models show that it is possible to utilise a single equation (the reduced model) to estimate the form factor for all spacings, indicating that the factor was not influenced by plantation spacing. It was found that with increasing diameter, teak tree trunks became more cylindrical. Stabilisation occurs starting at a diameter of 27 cm and a height of 25 m, with a form factor of 0.47.
 
 
Key words: Teak, volumetric, plantation density.