Modelos locais de produção de látex em seringueira utilizando variáveis dendrométricas e de sensoriamento remoto

Abstract

The rubber tree (Hevea Brasilienses Muell. Arg.) is considered the most important source of natural rubber in the world. Due to the characteristics of elasticity and high impact resistance, it is difficult to replace it with synthetic rubber. As the main raw material, it is essential to evaluate different ways of obtaining the estimate of latex production. In this sense, the objective of this work was to model latex production in a rubber tree plantation using dendrometric (DV) and remote sensing (SR) variables. The plantation is located in Monte Carmelo, Minas Gerais, with 13.2 ha, with the cultivar RRIM 600, planted at a spacing of 8.00 x 2.90 m, with 11 years of age. Through a forest inventory with the release of eight sampling units, the diameter at breast height (d), total height (h), commercial height (hc) and latex production (l) were measured. Satellite images were obtained through the USGS (United States Geological Survey) platform, using images from the Sentinel 2A satellite, for the date on which data collection was performed. Spearman's correlation analysis was used to determine the degree of association between latex production with RV and SR. The modeling of latex production was performed using regression analysis techniques, and models were evaluated to estimate latex production per tree and per sampling unit. The criteria used to evaluate the performance of the developed models were the adjusted coefficient of determination (R2ajust), crude coefficient of determination (R_b^2), standard error of the percentage estimate (Syx%) and graphical analysis of residuals. To verify the statistical similarity of the latex production estimates, Graybill (1976) test was used. The dendrometric variables analyzed were not able to provide adequate estimates of latex production, both per tree and per sampling unit. The average production of latex in the area was 553.34 ± 77.52 kg ha-1 and the production per tree was 8.15 kg year-1. Through the analysis of the NDVI index, the plantation is in stage A and its leaf vigor is classified from very low to low. The vegetation index that best represented the behavior of the area was the GLI index.