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

NCPN Network News

Fiscal Year 2021 Open Period

NCPN Open Period

NCPN provides high quality asexually propagated plant material tested for targeted plant pathogens and pests to protect the environment and ensure the global competitiveness of specialty crop producers. In FY 2021, APHIS will provide at least $5 million to support NCPN clean plant projects...

Posted on Thursday, July 16, 2020 at 2:45 PM

Rhonda Smith "Heroine of the Vineyards" Wraps up Career - American Vineyard Magazine


Congratulations to Rhonda Smith on her retirement! The “Heroine of the Vineyards” emerged as Sonoma County's resident expert on all things wine grape during her nearly 34 years as the viticulture advisor for the University of California Cooperative Extension. NCPN was fortunate to have...

Posted on Thursday, July 16, 2020 at 2:01 PM

International Year of Plant Health

IYPH2020 Logo Vertical  EN

The United Nations declared 2020 as the International Year of Plant Health (IYPH). Please join us in this once-in-a-lifetime opportunity and help protect the world's crops, forests, gardens, and landscapes against invasive pests. When we protect plant health, we protect the food we eat, the air...

Posted on Friday, February 14, 2020 at 2:38 PM

Joint Conference of the International Organization of Citrus Virologists XXI and the International Research Conference on Huanglongbing

Joint Conference of the International Organization of Citrus Virologists XXI and the International Research Conference on Huanglongbing   March 10-15, 2019 Riverside CA Conference website

Posted on Tuesday, December 18, 2018 at 9:03 AM

Article available: What is Rose Rosette Disease?

New open access article on RRD published by HortScience: What is Rose Rosette Disease?  

Posted on Thursday, August 2, 2018 at 1:26 PM

Dr. Georgios Vidalakis Awarded APS Excellence in Regulatory Affairs and Crop Security

Georgios Vidalakis, chair of NCPN-Citrus, has been recognized by the American Phytopathological Society for his outstanding contributions to regulatory plant pathology and crop security. Read more at the link below:...

Posted on Wednesday, May 16, 2018 at 7:49 AM

Rose Rosette Disease Video Available

View the 'What Wednesday' video clip on Rose Rosette disease: TXPlantClinic/videos/ 10154736863317558/   Are you aware there is a website dedicated to Rose Rosette disease? Check it out at:

Posted on Wednesday, May 16, 2018 at 7:43 AM

Grapevine 'Variety Focus' Lectures Available for Viewing

Grapevine ‘Variety Focus' lectures are now available on Foundation Plant Service's website at These lectures, from 2005-2011, were given by a talented group of guest speakers including UC Davis faculty, UC farm advisors, experienced California...

Posted on Wednesday, May 16, 2018 at 7:41 AM

Video on Virus Elimination Therapy

"Excising sweetpotato microshoot tips for virus elimination therapy” is now available on YouTube.

Posted on Wednesday, May 16, 2018 at 7:35 AM

Breeding for Disease Resistance

RosBREED is a national research and extension team focused on targeting breeding approaches in Rosaceae crops for disease resistance, horticultural quality and increased consumer satisfaction. Learn more about who is on the team and their research by clicking the link...

Posted on Wednesday, May 16, 2018 at 7:34 AM

Field Guide Integrated Pest Management in Hops

Start clean by purchasing virus tested hops for your yard and stay clean by following best management practices outlined in the link below.

Posted on Wednesday, May 16, 2018 at 7:30 AM

Five Terms Defined for Sweetpotato Clean Plant Programs

Virus indexing is a method used to determine the presence and identity of sweetpotato viruses.  The Brazilian morning glory (Ipomoea setosa), a close relative to sweetpotato, is sensitive to sweetpotato viruses. I. setosa is referred to as an indicator species because when infected...

Posted on Saturday, January 6, 2018 at 1:22 PM

Five Ways to Manage Rose Rosette Disease

Monitor for symptoms frequently (once per week). Bag and remove diseased plants quickly (there is no known cure for Rose Rosette disease).Bagging is necessary to prevent further spread of the disease via the air borne mite vector. Remove the root ball. This does not have to be bagged as the mite...

Posted on Saturday, January 6, 2018 at 1:01 PM

Tips for Managing Hop Viruses in the Field

Plant with propagation material that is virus indexed. Destroy and replace diseased plants with virus-indexed plants as soon as possible to limit spread. Start work in virus-indexed yards before working in infected yards, to preclude transferring pests and other vectors between...

Posted on Saturday, January 6, 2018 at 1:00 PM

Five Facts About Grape Viruses and NCPN-Grapes

Wine quality is affected by a very common disease, leafroll disease, which reduces sugar content and color of grapes and increases acidity. Leafroll disease is caused by one or more viruses in the grapevine leafroll virus species. Archived leaf tissue in the UC Davis Herbarium from the...

Posted on Saturday, January 6, 2018 at 12:58 PM

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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