2021 journal article
Results from Hop Cultivar Trials in Mid-Atlantic United States
HORTTECHNOLOGY, 31(4), 542–551.
‘Hop’ ( Humulus lupulus ) cultivar trials were conducted at sites in three Virginia counties (Northampton, Chesterfield, and Madison) in response to demand by the craft beer industry for local ingredients. In 2016, a replicated study involving five cultivars (Cascade, Chinook, Newport, Nugget, and Zeus) was established on an 18-ft-tall trellis system at each site. Weather data influencing infectivity of downy mildew ( Pseudoperonospora humuli ) and powdery mildew ( Podosphaera macularis ), two economically important hop diseases, was collected, and to the extent possible, similar cultural practices were applied at each site. Climatic conditions favorable to P. humuli and P. macularis were present throughout the experimental period, and P. humuli infection was widespread at all sites starting from 2017. Among common pests, Japanese beetle ( Popillia japonica ) was the only one observed to cause significant damage. Unseasonably high rainfall in 2018 led to crop failure at all but the Northampton site, and harvesting was done at all sites only in 2017 and 2019. Yields (kilograms per hectare by weight) in 2017 were found to be ≥45% lower than second-year estimates for yards in the north and northwestern United States. Quality attributes (α and β acids; essential oil) for cones harvested from the Chesterfield site were comparable to published ranges for ‘Cascade’ in 2019, but lower for the other cultivars. More work is needed to identify or develop cultivars better suited to conditions in the southeastern United States. The influence of terroir on quality of commercial cultivars produced in the region should also be examined.