Indirect and expedite assessment of Ilex paraguariensis commercial yield

Abstract

Commercial biomass production is one of the main indicators for selecting erva-mate (Ilex paraguariensis) progenies and clones. Traditional techniques to obtain such information depend on the harvesting of trees and there are some limitations involved, such as high cost and reduced convenience. Thus, in our research we evaluated the efficiency of indirect methods through commercial biomass estimation and score of productivity according to the different provenances, gender and morphotypes. In a provenances and progenies trial installed in 1997, two methodologies of visual analysis were evaluated in August 2015 (two years after the last harvest). For that reason, five expert evaluators determined, for each plant, an estimate of the commercial biomass (kg), and a grade, based on a score of productivity (0-10). In order to assess the productivity using traditional techniques, all plants were pruned and their commercial biomass (leaves and fine branches smaller than 7 mm diameter) were harvested and weighed (kg.plant-1). The evaluations were performed in a randomized-block experiment with five repetitions, seven different provenances and 126 progenies, totaling 5,292 evaluated plants. The methods utilized were effective to estimate the commercial biomass. The evaluators showed accuracy, expressing efficiently the largest productivity obtained when comparing the means of provenances, plants gender and morphotypes. The highest correlations were observed in the general analysis of the means, and the estimation of commercial biomass was considered the best methodology for estimating the commercial biomass assessed in adult erva-mate plants.