Hops are used in brewing and are commonly grown in the Pacific Northwest of the United States, Europe (especially Germany and the United Kingdom), Australia and New Zealand.
Hops grow from rhizome cuttings of female hop plants. Hop vines grow up to 4.5 to 7.5 m or more during the growing season. These vines are trained to climb up heavy trellis wire or heavy cords. Hops are traditionally spaced 2 m apart in each direction with two cords per plant going to the overhead trellis wire at about 45° angles. Trellises are about 5.5 m high and are made from 10 ´ 10 cm pressure-treated timbers or poles sunk 0.6 to 1 m into the ground.
Manual labour is used to train the vines after the vines reach about a third of a metre in length; additionally, the lowest metre is pruned to allow air circulation to reduce disease development.
Hops vines are harvested in the fall. In the United Kingdom, some hops are grown in trellises 3 m high and harvested with an over-the-row mechanical harvester. In the United States, hop combines are available to harvest 5.5-m-high trellises. The areas that the harvesters (field strippers) are unable to get are harvested by hand with a machete. Newly harvested hops are then kiln dried from 80% moisture to about 10%. Hops are cooled, then baled and taken to cold storage for end use.
Workers need to wear long sleeves and gloves when working near the vines, because hooked hairs of the plant may cause a rash on the skin. Some individuals become more sensitized to the vines than others.
A majority of the injuries involve strains and sprains due to lifting materials such as irrigation pipes and bales, and over-reaching when working on trellises. Workers should be trained in lifting or mechanical aids should be used.
Workers need to wear chaps at the knee and below to protect the leg from cuts while cutting the vines by hand. Eye protection is a must while working with the vines.
Many injuries occur while workers tie twine to the wire trellis wire. Most work is performed while standing on high trailers or platforms on tractors. Accidents have been reduced by providing safety belts or guard rails to prevent falls, and by wearing eye protection. Because there is much movement with the hands, carpal tunnel syndrome may be a problem.
Since hops are often treated with fungicides during the season, proper posting of re-entry intervals is needed.
Worker’s compensation claims in Washington State (US) tend to indicate that injury incidence ranges between 30 and 40 injuries per 100 person years worked. Growers through their association have safety committees that actively work to lower injury rates. Injury rates in Washington are similar to those found in the tree fruit industry and dairy. Highest injury incidence tends to occur in August and September.
The industry has unique practices in the production of the product, where much of the machinery and equipment is locally manufactured. By the vigilance of the safety committees to provide adequate machine guarding, they are able to reduce “caught in” type injuries within the harvesting and processing operations. Training should focus on proper use of knives, PPE and prevention of falls from vehicles and other machines.