Growing hops (Humulus lupulus L.) in subtropical climates: Effects of climatic patterns on phenology and seasonal crop performance

Crop diversification has emerged as a crucial strategy for advancing agricultural sustainability and mitigating the impacts of climate change, while also presenting novel economic opportunities in emerging climatic zones. The burgeoning global craft beer industry has intensified interest in cultivating hops (Humulus lupulus L.) in nontraditional regions, including Brazil, the Southeastern United States, and the Mediterranean. Traditionally adapted to temperate climates, hops must be acclimated to local conditions for successful cultivation in new environments. This study assessed various methodologies for calculating growing degree days (GDDs) and found that Method I demonstrated superior stability for both vegetative and reproductive phases, though Method II exhibited a better overall fit. While the application of T_max > 30°C corrections reduced variability and enhanced R² values, no single method proved definitively superior. Analysis indicated elevated GDD requirements during vegetative stages, attributable to increased thermal averages across the 2-year study period. Positive correlations between GDDs and biometric data suggest distinctive growth responses in subtropical environments compared to temperate regions. Quality evaluations revealed significant variability in bittering and aromatic compounds, with spring 2021 showing higher overall quality. These findings advocate for the viability of a double annual harvest as a strategic approach to optimizing hop production in subtropical climates. The results underscore the necessity for appropriate infrastructure to support post-harvest processing and provide valuable insights for local agricultural stakeholders and brewing industries.