• The USDA's Tree Assistance Program (TAP) provides financial aid to California winegrape growers who have suffered losses due to the Red Blotch Virus (GRBaV), Pierce’s Disease and Leafroll Viruses,
• Eligibility. Growers in specific California counties, including Amador, Contra Costa, El Dorado, Fresno, Marin, Mendocino, Monterey, Napa, Riverside, Sacramento, San Joaquin, San Luis Obispo, San Mateo, Santa Barbara, Santa Cruz, Solano, Sonoma, and Yolo
• Application. Applicants must apply within 90 days of the disaster event or when the loss is apparent. Applications are accepted until funding runs out.
• Process. Before removing any vines, applicants must have a FSA representative visit the site and test ten samples from each block to be replanted.
• Restrictions. Applicants must have an average adjusted gross income (AGI) of less than $900,000.
• TAP is administered by the USDA Farm Service Agency (FSA). The program was made permanent by the 2014 Farm Bill.
• The Red Blotch Virus is spread by grafting and propagation of infected plant material, and by insect vectors. It's not known if the virus can be spread by unsanitary equipment.
• Agri-Analysis is an approved laboratory and has helped growers meeting the testing requirements for over ten years. Please give us a call or email us today.

Research funded by American Vineyard Foundation (AVF) found that in Washington, Oregon and California, over 90% powdery mildew samples tested were found to be resistant to QoI (FRAC Class 11) and about 60% were resistant to both QOI and DMI (FRAC Class 3) (2017 data). The QoI resistance is attributed to a single point glycine to alanine mutation at position 143 of cytochrome b gene (G143A) of Erysiphe necator.  A change from tyrosine to phenylalanine in the cytochrome 450 gene (Y136F) is associated with tolerance higher DMI fungicide.

What is Qualitative Resistance?  It is like a light switch on or off.  For resistance to quinone outside inhibitor (QoI) fungicides (FRAC Group 11), the identification of the G143A mutation in Cytochrome b indicates that QoI resistance is present.  This is a classic case of qualitative resistance where resistance comes from the modification of a single major gene (Cytochrome b), Erysiphe necator subpopulations are either sensitive or fully resistant to the fungicide.  The FRAME Research team has only found the G143A in the CYTb gene from over 400 samples sequenced.  

What is Quantitative Resistance?  It is like getting a suntan.  A slow progression in tolerating higher and higher dose or the gradual erosion of disease control over time.  For resistance to DeMethylation Inhibitors (DMI) fungicide (FRAC group 3), the FRAME Research team has found Y136F mutation to be associated with most resistant isolates. In addition, there is a correlation of copy number of Y136F to DMI tolerance level.  CYP51 mutation copy number is important.  Isolates with high copy number of CYP51 with Y136F mutation is 99% likely to be highly tolerant.  If these mutations are present, in the short time, the disease may be managed by increased dosage.  However, eventually, even the highest manufacturer's suggested rates and/or shortest application intervals may fail to adequately control the disease.    

Here at Agri-Analysis, we use a combination of qPCR and DNA sequencing to accurately determine the G143A and Y136F mutations and estimate the relative abundance of mutated vs wild type E. necator from field samples. Please contact us at info@agri-analysis.com for more details and questions.

We have studied the relative level of red blotch virus in green grafted vines and found that the virus titer level can vary significant in different parts of the vine. Sampling positions and data are shown below.  This knowledge has been instrumental in guiding us how to best sample the green vine in order to provide the most accurate results during this time of the year. 

[TAP (REV. 4) OR AMEND 1] states that "The STC has approved Grapevine Red Blotch-associated Virus (GRBaV), commonly referred to as "Red Blotch", as an eligible plant disease for select counties in Oregon and California.  A claim of loss due to GRBaV must be verified through polymerase chain reaction (PCR) testing performed at a commercial laboratory."  In addition to red blotch, leafroll and Pierce's Diseases are also eligible under TAP.  For more information, please refer to the USDA fact sheet. A minimum of ten (10) symptomatic vines must be tested from each block claimed to be infected. This sampling, coupled with visual indicators identifiable to the FSA representative, will be used to determine the extent of damage. To apply for TAP, please contact your county USDA Farm Service Agency (FSA) offices. For tesing, please contact Agri-Analysis at info@agri-analysis.com or call us at (800)506-9852 ext 3.

As you source for clean materials for the upcoming seasons, whether they are from your own vineyards, a neighbor's, a friend's or a nursery, we would like to share some good practices from growers who are in the know in order to best protect your investment:

1. All plant materials, including top grafting vines or new scion buds, should have their virus status independently tested and verified.

2. Depending on the number of buds (i.e. vines) needed, back-calculate the number of mother vines needed with certain overage ratio based on the number of buds per mother vine.

3. Sample and test every mother vine for a suitable panel of economically important viruses prior to grafting.

4. Use composite sampling to reduce testing cost. We can process up to ten cuttings per sample.

5. If testing the mother vines are impractical, use statistically sound methods to sample and test starting, finishing, or finished product

6. If testing budget is limited, test, at the least, grapevine leafroll 3 virus and red blotch virus - two of the most devastating viruses affecting grape production.

7. Inspect potted and bare root vines suitably in advance before delivery for physical conditions to permit sourcing of alternate materials should plants be in poor physical condition or test positive for virus.

8. Consider hiring an outside experienced expert if your internal resources are limited.

Please contact Agri-Analysis at (800)506-952 and info@agri-analysis.com; or James at 707-217-2539 and james@jamesstamp.net.

Grapevine diseases can be caused by viral, bacterial and fungal pathogens and/or combination of them. Infections by these pathogens can have severe negative impact on vine health and grape production.  Diseased vineyards are not physically, economically and ecologically sustainable. Located in Davis, CA, Agri-Analysis continues to be the center of excellence in testing grapevine viruses and diseases since 1981.  Our grapevine disease testing service can help identity the exact cause of a diseases and help track and trace its potential origin. Testing is a value added investment to help clients make informed decisions and mitigate risks in these and related areas:

1) Source and screen new planting materials such as budwood, rootstocks; and finished products from nurseries and/or other sources;

2) Survey the health status of existing vineyards to make informed management decisions;

3) Meet requirements of federal, state, and local programs such as the USDA Tree Assistance Program (TAP);

4) Meet requirements of various sustainability programs such as Napa Green;

5) Diagnosis of vineyard abnormalities such as leaf reddening, sudden vine collapse, stunted growth, cankers, diebacks, uneven lignification, crown gall, low brix, delayed ripening, and abnormal wine chemistry characteristics, etc.

6) Due diligence in vineyard transactions for both buyers and sellers;

7) Positively identify bed blotch and/or LR3 and other virus infected vines for elimination so that they do not become an innoculum source for insect-mediated new infections.

If you have any of these needs, please contact us, or download our sample submission form here.

California's world-class wines depends on the health and well being of our premium vineyards. Diseased vineyards are not physically, economically and ecologically sustainable. Located in Davis, CA, Agri-Analysis continues to be the center of excellence in testing grapevine viruses and diseases since 1981.  Our Grapevine virus testing service is value added investment to help clients make informed decisions and mitigate risks in these and related areas:

1) Source and screen new planting materials such as budwood, rootstocks; and finished products from nurseries and/or other sources;

2) Survey the health status of existing vineyards to make informed management decisions;

3) Meet requirements of federal, state, and local programs such as the USDA Tree Assistance Program (TAP);

4) Meet requirements of various sustainability programs such as Napa Green;

5) Diagnosis of vineyard abnormalities such as leaf reddening, low brix, delayed ripening, and wine chemistry characteristics

6) Due diligence in vineyard transactions for both buyers and sellers;

7) Positively identify bed blotch and/or LR3 infected vines for elimination so that they do not become an innoculum source for insect-mediated new infections.

If you have any of these needs, please contact us, or download our sample submission form here.

As you make post-harvest plans for new plantings next year, we encourage growers to continue their vigilance against viruses and diseases by conducting independent quality control of new planting materials. Agri-Analysis has provided virus testing services for vineyard, winery, and nursery clients worldwide since 1981. Here is some advice from industry expert Dr. James Stamp when sourcing for quality grapevine stock nurseries or other sources:

1.  All plant materials should have their virus status independently tested and verified.

2.  Use statistically sound methods to sample and test starting, finishing or finished product for, at the least, grapevine leafroll 3 virus and red blotch virus - two of the most devastating viruses affecting grape production.

3.  Ideally, test ALL mother vines for a suitable panel of economically important viruses prior to grafting.

4.  If possible, inspect potted and bare root vines suitably in advance before delivery to permit sourcing of alternate materials should plants be in poor physical condition or test positive for virus.

Please contact Agri-Analysis at (800)506-952 and info@agri-analysis.com; or James at 707-217-2539 and james@jamesstamp.net.

Our Grapevine Red Blotch Virus testing service has helped clients: 

1. 1Source and screen new planting materials such as budwood and rootstocks; 
2. Survey the health status of existing vineyards; 
3. Meet requirements of federal, state, and local assistance programs such as the Tree Assistance Program (TAP); 
4. Meet requirements of various sustainability programs; 
5. Diagnose vineyard abnormalities such as low Brix; 
6. Due diligence in vineyard transactions to protect both buyers and sellers. 

"No Vines, No Wines." California's world-class wines depend on the health and well being of our premium vineyards. Disease infected vineyards are not physically, economically and ecologically sustainable. Located in Davis CA, Agri-Analysis has proudly provided grapevine disease testing services to grapegrowers since 1981. We use state of the art technologies such as ELISA, PCR, RT-PCR, qPCR, DNA sequencing, fluorescence, bioluminescence, chemiluminescence and nanotechnology to help growers protect their investments and mitigate risks in winegrape production.

Please call or email us to discuss your testing needs. 

Agri-Analysis LLC

950 West Chiles Road

Davis, CA 95618

Tel: (800)506-9852

Email: info@agri-analysis.com

While next generation sequencing (NGS) is receiving all the headlines, traditional Sanger sequencing is carrying on the grunt of the work in day-to-day laboratory analysis. Here at Agri-Analysis we routinely use DNA sequencing, combined with other techniques such as PCR or RT-PCR, to help answer growers questions in number of areas:

1. Pathogenic strains of Agrobacterium vitis are known to be the causal agent for crown diseases. PCR alone is insufficient for the reliable identification of A. Vitis. We use a combination of PCR followed by DNA sequencing for reliable identification of A. vitis in both vineyards and nursery materials.
   
2. Confirmation of fungicide resistance of powdery mildew to Qoi (Franc 11 ) and DMI (frac 3) fungicides in grapevines has been increasingly requested by growers when they experience field failures when using these fungicides.  PCR followed by DNA Sequencing can help us pin-point the exact mutations in PM genes attributable to resistance.
   
3. Grapevine leafroll associated virus type 3 (GLRaV-3) is the most devastating virus in grape production worldwide.  Because GLRaV-3 genomes are highly variant, some strains can escape detection.  We have used PcR followed by DNA sequencing for early discovery and testing of the emergence of a new grapevine leafroll associated virus type 3 (GLRaV-3) variant in commercial vineyards.  Our work preceded the discovery of the same by NGS by several years. This provided us with a competitive advantage by being able to test for the new variant several years before its identification and publication by researchers.
   
4. Cherry X disease, attributable to candidatus phytoplasma, is an economically impactful disease in the cherry producing regions of the U.S.  We have used nested-PCR followed by DNA sequencing for identification and confirmation of phytoplasma infection in cherry orchards in California.
   
5. We have used PCR followed by DNA sequencing for the identification and confirmation of infection by a number of known viruses in Apple and Cherry orchards such as Apple Stem Grooving virus, Apple chlorotic leaf spot virus, prunus dwarf virus and prunus necrotic ringspot virus.
   
6. We have used PCR followed by DNA sequencing  identification and confirmation of hop latent viroid (HLVd) which is the biggest concern for cannabis and hop growers worldwide although most HLVd-infected plants can remain asymptomatic.
   
7. We have used PCR followed by DNA sequencing identification and confirmation of new infection of a known virus such as Pinot Gris virus (GPGV) for the first time in California commercial vineyards;
   
8. We have used PCR followed by DNA sequencing for clade typing and phylogenetic analysis of viruses in infected plants. For example, we found that GPGV infections in California vineyards, to date, are attributable to the non-symptomatic clade of GPGV which is less economically damaging than its symptomatic variant.
   
9. Sometimes, we are asked to conduct clade typing analysis of grapevine red blotch virus in infected vines to aid growers tracking where the infection may have initiated and spread. There are two known clades of GRBaV which vary by about 7% in genetic sequences but otherwise are phenotypically identical. 

Please email me at apwei@agri-analysis.com with any questions and comments on this and other topics.

An example of a DNA sequencing chromatogram (partial).