Under Johannis Raiser's influence, low trellis hop production expanded to Europe, to Bulgaria, under Bulgarsko Pivo, where it flourished. As much as 500 acres of low trellis hops were produced there during its prime in the 1980's. HopUnion, under the direction of Johannes Raiser, took Bulgarsko Pivo under its wing, and contracted with the company to supply hops for low trellis and create new varieties, as well as providing technical support and equipment. The collapse of the Communist system in 1991, however, created chaos in the Bulgarian hop industry and for several years very little was known about who controlled the industry or whether the industry would continue at all. Today in Bulgaria, low-trellis production is greatly reduced from its heyday but still remains quite strong.
Hop production in Bulgaria was losing momentum until the world hop shortages of 2006 & 2007 revived the industry. The country produces primarily American hop varieties and still maintains several hundred acres of low-trellis hops. Hop production is in the Velingrad and Rakitovo regions in the southern parts of the country. From a western perspective, following the collapse of the Soviet Union and it's influence in the area, there emerged a great uncertainty regarding the future of the Bulgarian hop industry. It emerged as a private firm under the control of Vladimir Ivanov, but since the mid 1990's acreage has been on a steady decline to roughly half of its former glory.
In China hops have been grown on low trellis since their inception. The vines are completely cut down by hand, loaded into sacks and driven to a stationary picking facility were the cones are stripped and separated from the leaves and stems. Each worker responsible for several rows manage some large fields. Government farms are encouraged to employ their workers.
The Fubei Sapporo Farm in Urumqi, supplements their hand picking with smaller Japanese UK style picking machines produced in the Czech Republic.
Low trellis hop production has developed significantly in England since the 1970's. Acreage of low trellis and dwarf hops remains strong and continues to increase while overall acreage in the country continues to decrease.
As of 2007, low trellis and dwarf hop production was the strongest part of a shrinking industry. The English hop industry is plagued by some of the highest labor costs in the world. It is, in effect, the canary in the coal mine.
England represents what will happen to hop industries around the world if prices remain low and new innovation is not encouraged and developed. Because of these facts, low trellis and dwarf hop production has flourished in England in recent years. The varieties developed there and techniques learned through the experiences of English growers will benefit low trellis growers worldwide.
French hop growers do not currently produce hops on low trellis but they have tests beginning in the 1970's.
The French hop industry, represented by Cophudal, conducted extensive feasibility studies regarding hop production on low-trellis as late as 2004. The reports concluded that low trellis hop production is a cost effective way to produce hops, in particular the Tradition variety. Ironically, despite these findings, growers have moved away from this method in favor of the typical French 7 meter (22.75 feet) high trellis.
Based on the experiences gained with low trellis systems in hop production in the USA and UK trials to grow hops on low trellis systems were conducted between 1993 till 2002 funded by the German Federal Ministry of Food, Agriculture and Consumer Protection via the Federal Agency for Agriculture and Nutrition (BLE). Within these R&D projects trials on low trellis wireworks were conducted in Bavaria and Saxony on an acreage of approximately (1.6 ha in Bavaria, 1 ha in Saxony, 2.1 ha in Tettnang) aiming to investigate various economical and ecological aspects of this new production system. Mr Rossbauer from the Bavarian State Research Center for Soil Science and Crop Production, Hop Production Group, (the today´s Bavarian State Research Center for Agriculture) was in over all charge of these trials.
In 1998 Dr. Darby provided his dwarf varieties First Gold, Pioneer and Herald as references for the trials on low trellis wirework. And from 1999 onwards these real dwarf cultivars could be compared to the performance of high trellis Huell cultivars and of Huell breeding lines with less vigorous growth or growing characteristics similar to the English dwarfs. Special focus was put on yield, disease susceptibility and brewing quality. Huell breeds selected for the growth on 7 m high trellis showed 40-60 % less yield when grown on 3 meter-trellis. The English dwarfs showed much better yield, but were highly susceptible to downy mildew and did not fully comply with the demands for high alpha acids or excellent aroma.
The trials stopped in 2002 with the end of the R&D projects. Results obtained during these years showed some potential for cost savings due to reduced training work (non- cultivation with no cutting in spring and only self-training, was not satisfying), less amounts of fertilizers and pesticides. But it clearly turned out that new hop varieties especially suitable for the growth on low trellis systems were urgently needed.
In 2007 after getting financial support once more from the Federal Agency for Agriculture and Nutrition (BLE) efforts started to develop hops especially adapted to the growth on low trellis systems. Now special crosses are conducted each year and systematic selection for hops suitable for low trellis wirework is performed. Now on 1.5 ha in Bavaria and 1.6 ha in the Elbe-Saale hop growing region new breeding lines and the above mentioned real English dwarfs First Gold, Herald and Pioneer are grown. So far there are a few breeding lines showing better performance in single traits, but hop varieties fulfilling all demands - good yield, broad resistance or tolerance to diseases and excellent brewing quality - are not available so far.
In addition, the harvest technique and special cultivation steps have to be improved.
The production of hops on low trellis system so far was and is only used for research, not in practice.
Information provided by:
Dr. Elisabeth Seigner
Bayerische Landesanstalt für Landwirtschaft Institut für Pflanzenbau und Pflanzenzuechtung Arbeitsbereich Hopfen, Zuechtungsforschung