Journal of Agricultural Science; Vol. 11, No. 10; 2019 ISSN 1916-9752 E-ISSN 1916-9760 Published by Canadian Center of Science and Education 154 Alometric Model for Estimation of Leaf Area of Garcinia brasiliensis Mart. Through Non-destructive Method Vinicius de Souza Oliveira 1 , Cássio Francisco Moreira de Carvalho 1 , Juliany Morosini França 1 , Flávia Barreto Pinto 1 , Karina Tiemi Hassuda dos Santos 2 , Jéssica Sayuri Hassuda Santos 2 , Gleyce Pereira Santos 2 , Ana Paula Braido Pinheiro 1 , Omar Schmildt 1 , Marcio Paulo Czepak 2 , Sara Dousseau Arantes 3 , Rodrigo Sobreira Alexandre 4 , José Augusto Teixeira do Amaral 4 , Edney Leandro da Vitória 2 & Edilson Romais Schmildt 2 1 Postgraduate Program in Tropical Agriculture, Federal University of Espírito Santo, São Mateus, ES, Brazil 2 Departament of Agrarian and Biological Sciences, Federal University of Espírito Santo, São Mateus, ES, Brazil 3 Capixaba Institute for Research, Technical Assistance and Rural Extension, Regional Center for Rural Development, Brazil 4 Federal University of Espírito Santo, Alegre, ES, Brazil Correspondence: Vinicius de Souza Oliveira, Postgraduate Program in Tropical Agriculture, Federal University of Espírito Santo, São Mateus, ES, Brazil. E-mail: souzaoliveiravini@gmail.com Received: April 1, 2019 Accepted: May 13, 2019 Online Published: July 15, 2019 doi:10.5539/jas.v11n10p154 URL: https://doi.org/10.5539/jas.v11n10p154 Abstract The objective of the present study was to test and establish mathematical models to estimate the leaf area of Garcinia brasiliensis Mart. through linear dimensions of the length, width and product of both measurements. In this way, 500 leaves of trees with age between 4 and 6 years were collected from all the cardinal points of the plant in the municipality of São Mateus, North of the State of Espírito Santo, Brazil. The length (L) along the main midrib, the maximum width (W), the product of the length with the width (LW) and the observed leaf area (OLA) were obtained for all leaves. From these measurements were adjusted linear equations of first degree, quadratic and power, in which OLA was used as dependent variable as function of L, W and LW as independent variable. For the validation, the values of L, W and LW of 100 random leaves were substituted in the equations generated in the modeling, thus obtaining the estimated leaf area (ELA). The values of the means of ELA and OLA were tested by Student’s t test 5% of probability. The mean absolute error (MAE), root mean square error (RMSE) and Willmott’s index d for all proposed models were also determined. The choice of the best model was based on the non significant values in the comparison of the means of ELA and OLA, values of MAE and RMSE closer to zero and value of the index d and coefficient of determination (R 2 ) close to unity. The equation that best estimates leaf area of Garcinia brasiliensis Mart. in a way non-destructive is the power model represented by por ELA = 0.7470(LW) 0.9842 and R 2 = 0.9949. Keywords: Garcinia brasiliensis Mart., mathematical models, modeling of leaf area, foliar allometry 1. Introduction The species Garcinia brasiliensis Mart. (Rheedia brasiliensis Planch e Triana), belonging to the family Clusiaceae, commonly known as bacuri, bacupari, porocó and bacuripari, is a native of the Amazon region and having specimens spread throughout the Brazilian territory, being an important source of food for the fauna, as well as use as raw material for medicine (Oliveira, Ribeiro, Matias, Gusmão, & Pereira, 2011). Its therapeutic potential and its compounds provide multiple medicinal activities such as antianphylactic, antimicrobial, antispasmodic, anti-inflammatory, antioxidant, antiproteolytic, antiproliferative and leishmanicidal (Pereira et al., 2010; Santa-Cecília et al., 2013). Allometry in determining leaf area is an important biological attribute of plant growth, which affects biological and economic productivity (Schwab et al., 2014). It is possible to estimate the transpiration intensity, net assimilation rate, leaf area ratio, specific leaf area and leaf area index, in addition, quantifies variations in growth due to genetic or environmental changes (Marrocos et al., 2010). The estimation of the leaf area can be done by direct and indirect methods. The direct methods involve the