Yerba-mate (Ilex paraguariensis St. Hil.) is a subtropical, evergreen, dioecious, South-American tree, and an economically important species, whose leaves and twigs are extensively used as a primary material in the preparation of diverse beverages. Its architecture is defined by Rauh's model, which comprises the rhythmic growth, and consequently, the existence of growth units. The aims of this study were to define the mathematical functions for growth unit formation related to various morphological parameters, to interpolate the 3D reconstructions for two-year period and to calculate the leaf/fine twig production of males and females cultivated in two contrasting environments (monoculture - and forest understory). For this purpose, InterpolMateS1, one deterministic and empirical model, has been developed. It interpolates the structural reconstructions of plants in 3D based on several known growth stages, and estimates the plant production for beverage industry. Various morphological characters were defined to parameterize the InterpolMateS1: metamer number, individual leaf size, main axes elongation, leaf number increase per axes, total leaf area, leaf shed per axes and branching. The VPlants and PlantGLViewer software were used for plant codifying and 3D reconstruction, while the modules of InterpolMateS1 were written in NetBeans IDE (Java). The cubic splines functions fitted correctly with the observed values of morphological characters during four growth flushes in two-year continuum. The out-put of useful biomass production in InterpolMateS1 was related to mock-up leaf area, fine branch volume and various forest productive parameters (i.e., specific leaf area, specific wood mass). The next steps in development of this forestry/agronomy useful software consider the coupling of yerba-mate mock-ups with carbon gain and storage on plant and landscape scale for two environments - monoculture and forest understory.