Characterization of hops (Humulus lupulus cultivar Hallertau Magnum) grown under different doses of nitrogen fertilization in a subtropical climate

Abstract

Hops are an essential ingredient in brewing, contributing to beer flavor and aroma. Brazil imports hop products such as pellets and extracts to meet domestic demand, while research on hop production under subtropical conditions remains limited. Nitrogen fertilization strongly affects hop growth and yield, although its effects on cone quality are not fully understood. This study evaluated the effects of nitrogen fertilization on ‘Hallertau Magnum’ hops grown under subtropical conditions during two consecutive production cycles between 2022 and 2023. Nitrogen (N) rates of 0, 90, 180 and 270 kg ha−1 were evaluated in a randomized complete block design. Cone yield increased significantly with N application in both production cycles, with the highest cone yield obtained at 270 kg ha−1 of N (426.7 g plant−1 in the 1st production cycle and 76.2 g plant−1 in the 2nd production cycle). The α- and β-acid contents were significantly affected only in the 2nd production cycle, increasing with increasing N rates. The marked reduction in productivity during the 2nd production cycle was mainly associated with less favorable photothermal conditions. These results indicate that hop production in subtropical regions is strongly influenced by seasonal environmental conditions, requiring adjustments in nitrogen management strategies adjusted according to crop phenology and harvest season.