Latest information on viticulture, UC research and newly released UC publications.
Apr 1, 2021
During drought years, we often experience large VMB populations, putting Napa vineyards at increased risk for crop damage and pest spread. Respond accordingly by scheduling early interventions to reduce populations.
Follow the newsletter link for an early April update on VMB populations.
Download (6,755KB PDF)
Jan 25, 2021
Dr. Jay Pscheidt and Sarah Lowder at Oregon State University are recruiting participants to a study on regional communication and group cooperation. If you are involved in pest or disease management decisions, please consider participating by completing one or both surveys.
Thank you in advance for your consideration & participation!
Survey 1: How do you communicate? (5- 10 minutes) https://oregonstate.qualtrics.com/jfe/form/SV_b9hHZAhnRS79feJ
Survey 2: What do you think about pest management? (20-30 minutes) https://oregonstate.qualtrics.com/jfe/form/SV_25hRtjl2G5JuBrn
Download (43KB PDF)
Dec 3, 2020
The Napa County Agricultural Commissioner's Office has reported the following information regarding the herbicide Weed Slayer.
"It has come to our attention that the organic herbicide, Weed Slayer, Agro Research International, is under investigation by the California Department of Food & Agriculture and the California Department of Pesticide Regulation for possible product contamination.
If you have any product in storage, we recommend that conventional and particularly organically certified growers do not apply the herbicide pending results from the ongoing investigations."
If you have any questions, please contact staff of the Ag Commissioner's office in your county.
For Napa, that is email@example.com or (707) 253-4357.
Download (94KB PDF)
Aug 13, 2020
Life cycle and monitoring guidelines for threecornered alfalfa hopper in vineyards.
Download (310KB PDF)
Jun 26, 2020
Three leafhopper species--western grape, variegated and Virginia creeper--are present in Napa vineyards. Both variegated and Virginia creeper are invasive species, whose range has expanded considerably in Napa in the last 10 years. Proper identification of vineyard leafhoppers is critical to development of a successful management strategy. Access the newsletter link below for a "Quick Reference Guide to North Coast Vineyard Leafhoppers".
Download (242KB PDF)
Jun 22, 2020
The UCCE-Napa viticulture team has a new resource for Pierce's disease: https://ucceviticulturenapa.wixsite.com/uccevitnapa/bgss-live-map
On this website you will find:
Blue-green sharpshooter trap counts from county-wide monitoring program
Guidelines for trapping blue-green sharpshooters
Resources for identifying common vectors
Sharpshooters and spittlebugs are vectors of Xylella fastidiosa, the causal agent of Pierce's disease of grapevines. In 2020, the UCCE-Napa viticulture team, with support from the Napa County Wine grape Pest and Disease Control District, launched a county-wide monitoring program for blue-green sharpshooter (BGSS), the most common vector in the north coast region. Trap data are updated in real time and are accessible via the link above. Trap data are viewable by growing region, by date, and by landscape category (riparian, ornamental, other).
Download (113KB PDF)
Dec 6, 2019
Spotted lanternfly is a newly invasive pest that has been found in several eastern states. Feeding activity and copious honeydew production can damage vines and fruit trees and promote the growth of sooty mold.
There is great potential for dispersal of this insect from the eastern US to other regions, given that females will lay eggs on a variety of inanimate objects (pallets, outdoor equipment, railway cars) that may be moved large distances.
UCCE IPM Advisor Cindy Kron developed these resources to support identification and detection efforts:
Vigilance and efforts to identify early invaders are critical to a successful response, should this pest be introduced to California. Report sightings and bring suspicious specimens to your local Agricultural Commissioner's office for confirmation.
Download (3,268KB PDF)
Apr 27, 2018
Follow the link to the newsletter below for more information on the status of resistance testing for grape powdery mildew for the DMI (FRAC 3) fungicides.
Download (343KB PDF)
Aug 10, 2017
Vine mealybug has been found on recent nursery shipments of green-growing vines in the North Coast region.
Follow the newsletter link below to learn more. The newsletter can be used as training tool for crews inspecting vines as they are received.
In Napa County, staff of the Agricultural Commissioner inspect all incoming shipments of green-growing vines and nursery plants. If you are expecting a shipment, contact the Agricultural Commissioner's office: (707) 253-4357
Download (22,933KB PDF)
Nov 3, 2015
In early September 2015, the California Department of Food & Agriculture confirmed the presence of thousand cankers disease of walnut in Napa County.
Access the newsletter below for additional information on this fungal disease and the beetle that moves it from tree to tree.
Download (5,462KB PDF)
Jul 8, 2015
On June 24, 2015, staff of the Napa County Agricultural Commissioner found one male Western Grapeleaf Skeletonizer in a pheromone-baited trap in a vineyard on Tubbs Lane in Calistoga.
UCCE Advisors Lucia Varela and Monica Cooper developed a "Monitoring Guide for Western Grapeleaf Skeletonizer" so that vineyard owners, growers and workers could familiarize themselves with the pest's life stages and feeding habits.
Please use the newsletter link below to access the Monitoring Guide (English and Spanish versions).
If you find this pest or feeding damage in Napa County please contact the office of the Agricultural Commissioner: 707-253-4357, firstname.lastname@example.org OR contact UC Cooperative Extension: 707-253-4221, email@example.com
For additional information on biology and management of this pest, access the UC IPM Pest Management Guide for Western Grapeleaf Skeletonizer.
Download (1,370KB PDF)
Jun 1, 2015
In April, we observed leaf symptoms in select vineyards consistent with feeding damage by arboreal camel crickets.
For photos and additional information, access the newsletter using the link provided below.
Download (33,926KB PDF)
Jan 20, 2014
Resources for water management of grapevines under drought conditions (courtesy of our colleagues in Australia) are available in the Irrigation section of the UC Cooperative Extension-Napa County website: http://cenapa.ucanr.edu/Napa_County_Programs/Viticulture/Irrigation/
Considerations for managing vine growth & yield under water-limiting conditions include:
1. Managing crop size through reductions in bud numbers and/or thinning after set. Adjust crop size to predicted water availability.
2. If possible, target supplementary irrigation to critical physiological periods: (a) budburst to flowering, (b) flowering to fruit set, (c) veraison to harvest, (d) harvest to leaf fall--hopefully will be raining by then!
3. Organic residues (from cover crops or weeds) and mulches may moderate soil surface temperatures.
Download (23KB PDF)
Jul 30, 2015
Update on Virginia creeper leafhopper (VCLH) populations:
Populations of Virginia creeper leafhopper (VCLH) have been identified in Napa County, in Pope Valley.
Follow the newsletter link below for additional information on VCLH and variegated leafhopper populations in Napa, including photos and links to additional training tools. Early detection and identification can be critical to avoiding economic injury.
Download (1,847KB PDF)
Feb 7, 2013
Dr. Arturo Calderon, Postdoctoral scholar, USDA and UC Davis has released an instructional video (in Spanish) on the use of the pressure bomb to measure grapevine leaf water potential.
We hope you will find this video to be a useful training tool.
Download (21KB PDF)
Jun 27, 2012
Since its introduction to the United States from Asia in the 1990's, the brown marmorated stink bug has become established in the mid-Atlantic states, as well as Portland, OR and Los Angeles, CA.
You can support pest prevention efforts by being aware, recognizing the pest, and reporting suspicious specimens.
The UC IPM Pest Alert Card for BMSB provides information on identification and damage. Consider printing and displaying it to increase awareness.
Download (2,022KB PDF)
Jun 20, 2012
We have updated our newsletter addressing phylloxera on resistant rootstocks.
Follow the newsletter link below to read our updated report.
Download (630KB PDF)
Mar 5, 2012
In January, Dr. Gubler and I visited a vineyard that seemed to have very clear symptoms of a trunk disease (Eutypa or Botryosphaeria). Yet when we looked closer, we determined the symptoms were not caused by a pathogen...link to the newsletter below to see photographs and read our full report.
Download (515KB PDF)
May 4, 2011
Thursday, May 26, 2011
9:00 am - 11:00 am
UC Davis Oakville Experimental Vineyard
1380 Oakville Grade Road
Speaker: Dr. Roger Baldwin, UC IPM, Statewide Vertebrate Control Advisor
Dr. Baldwin will provide an overview of pocket gophers and discuss the use of baiting and trapping. He will also provide demonstrations on baiting and trapping techniques.
Attendance is limited to 50 participants (3 maximum per company).
Pre-registration is required.
1.5 CE hours have been approved for this workshop.
Register at http://ucanr.org/gophercontrolworkshop
Download (110KB PDF)
Aug 26, 2010
It's that time of year: shriveled berries on ripening clusters. See the attached article by Krasnow et al. in California Agriculture. The authors describe the distinctive symptoms of 4 common types of berry shrivel disorder in grape in California.
Oct 31, 2008
Leafroll Spread and Plant Material information and survey form; Planting Material Workshop flyer and registration form; Napa County UCCE Viticulture Farm Advisor position, more..
Apr 1, 2008
Viticulture Program Representative, View from Below the Vine, Weed Field Meeting
May 27, 2007
New Weed Advisor in Napa Light Brown Apple Moth Herbicide Resistant Weeds ... More
Sep 30, 2004
Vine Mealybug - Little Good News Berry Shrivel Napa Valley Viticultural Fair ...More