National Clean Plant Network
National Clean Plant Network
National Clean Plant Network
University of California
National Clean Plant Network

Welcome to the National Clean Plant Network for Hops

NCPN-Hops logo



CPCNW Hop Plants 02


NCPN-Hops was added to the National Clean Plant Network in 2010. Currently there is one hop center in the network, the Clean Plant Center Northwest (CPCNW) at the Washington State University research and extension center in Prosser, Washington:

Since 1964, a virus-free certified hop planting stock program at WSU has been supported by industry contributions. Hop stunt disease is a devastating disease that can reduce hop yield by 60% or more. It was detected for the first time in the U.S. hop industry in 2004. By 2005, there was evidence that on-farm propagation of two different cultivars from diseased plants had resulted in large blocks of infected plants. Awareness of this development led to a dramatic increase in demand for reliable sources of disease-free hop propagation material. The state-oriented program quickly adopted a regional approach to help curb the further spread of hop stunt disease between production regions of the northwest, where virtually all of the commercial hop production of the U.S. occurs. The three northwest states produce 30% of the world’s hops and 37% of the world’s yield of alpha-acids. Support from the NCPN greatly accelerated the ability of the program to develop hop propagation material that is free of viruses and hop stunt disease, and to promote the use of disease-tested planting stock. This quick response was critical since current market volatility in the industry is inducing growers to establish niche markets with many specialized and diverse cultivars.

The hop program at CPCNW currently has 58 selections at various stages in the program; of these, 31 have been released and are available to the industry. At the request of the industry, the CPCNW recently obtained an NCPN pest permit to import hop propagation material directly from foreign sources. This new capacity will provide greater access for North American hop producers to hop cultivars developed and residing in other countries. Since 70% of the U.S. production is exported, it is important that the products from our farms meet global demands for quality and product innovation.

The clean plant centers within the hops network include:

NCPN LogoThe National Clean Plant Network (NCPN) produces and distributes asexually propagated plant material free of targeted graft transmissible plant pathogens to ensure the global competitiveness of specialty crop producers and to protect the environment. The NCPN operates under the auspices of three agencies within the United States Department of Agriculture - Animal and Plant Health Inspection Service (APHIS), Agricultural Research Service (ARS) and National Institute of Food and Agriculture (NIFA).



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