Nitrogenized Fertigation and Genotype Effects in Yerba Mate Leaf Production in a Semi-hydroponic System

Yerba mate (Ilex paraguariensis) is a South American tree, and its leaves are used for beverages, cosmetics, pharmaceutical, and other products. The global market demands raw materials with specific phytochemical characteristics and continuous supply throughout the year. Currently, in the field cultivation systems, yerba mate mature leaves are harvested every 18 or 24 months, and new production methods need to be developed to meet a growing demand for this species. Therefore, we studied the efficiency of a semi-hydroponic system as a new production method, evaluating the leaf production of distinct clones with five nitrogen concentrations in nutritive solution. The production of young and mature leaves of two genotypes (EC40 and EC22) was evaluated under increasing nitrogen (N) concentrations (114, 206, 380, 760, and 1142 mg L−1), over 11 harvests (2 years). There was a slight variation in production between harvests. Nitrogen concentration affected leaf production, and the lowest concentrations analyzed, 114 and 206 mg L−1, are recommended for both genotypes. The EC22 genotype showed a pronounced decrease in leaf production at high doses of N. The maximum annual yield of total fresh leaves occurred with 206 mg L−1 N in the second year, being 4.9 kg m−2 year−1 for both genotypes. The results confirm the efficiency of the proposed system since there is a large leaf production throughout the year. A similar proportion of young and mature leaves demonstrates the potential for different market niches. N concentrations and genotypes influenced yerba mate leaf production.