Cultivation trials of hop (Humulus lupulus L.) in a Mediterranean environment

In the modern brewing industry hops are an essential element for the characterization of the brewing product. Although several works have been addressed to evaluate the yield performance of hop in Northern Italian environments, scarce information is available about the suitability of hop to the semi-arid Mediterranean areas, where this crop could represent a valuable resource for farmers. Hop being a perennial crop, a major issue is the lack of knowledge about the mechanisms underlying the development of the hypogeal system related to cones yield. An experimentation was conducted in Sicily in 2018 and 2019, to test the growth and yield performance of three hop cultivars (‘Cascade’, ‘Chinook’, and ‘Nugget’). Biometrical characteristics, phenological stages, and plants’ development rates were evaluated, and put in relation to heat accumulation (GDD; °C). Furthermore, organic (fragmented pine bark) and synthetic (PE plastic film) mulches were applied. Finally, sensory analysis of the cones collected was carried out, by using them to brew small batches of beer. The results showed a high variability of yields and biometrical characteristics of the tested hop varieties according to the cropping management. Indeed, the cultivation technique was able to influence the accumulation trends of the hypogeal biomass, but this effect proved genotype-dependent. The development rates had a direct influence on the hypogeal biomass accumulation, even though they could not be considered a reliable indicator of productivity: the faster the growth in the first two phases of plants’ elongation, the lower the yield in both cones and total epigeal biomass. The sensory analyses assessed the excellent organoleptic characteristics of Sicilian hops, as well as of beers produced. Hop demonstrates to be a promising crop for semi-arid Mediterranean environments although a proper choice of the variety demonstrated crucial.