Napa County UCCE
University of California
Napa County UCCE

Vineyard Views & Events

Latest information on viticulture, UC research and newly released UC publications.

Issue Articles Type Date Added
Monitoring and Detecting DMI Fungicide Resistance in Grape Powdery Mildew (343KB)

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. 

PDF 4/27/18
Inspecting green-growing vines for VMB (22,963KB)

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

PDF 8/10/17
Potential benefits of powdery mildew resistant grapevines (201KB)

Recent research from the UC Davis Department of Agricultural and Resource Economics evaluated the potential economic benefits to California of powdery mildew resistant grapevines. (See newsletter link below).

As a follow-up to this study, the research team is collecting information on grower preferences for specific traits. We would appreciate if you could take a few minutes to respond to their survey questionshttps://okstatecasnr.az1.qualtrics.com/SE/?SID=SV_5AwMOELdrMZ9xJ3

Please direct questions to Olena Sambucci, sambucci@primal.ucdavis.edu

PDF 12/10/15
Walnut Twig Beetle and Thousand Cankers Disease (5,462KB)

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. 

PDF 11/3/15
Monitoring Guide for Western Grapeleaf Skeletonizer (1,370KB)

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, agcommissioner@countyofnapa.org OR contact UC Cooperative Extension: 707-253-4221, cenapa@ucanr.edu

For additional information on biology and management of this pest, access the UC IPM Pest Management Guide for Western Grapeleaf Skeletonizer

PDF 7/8/15
Arboreal Camel Cricket (33,926KB)

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. 

PDF 6/1/15
Vine mealybug management and FAQs (10,329KB)

The Napa County Wine grape Pest & Disease Control District sponsored a seminar on vine mealybug (VMB) on February 25. We discussed VMB detection, biology and management. As a follow-up, this article summarizes significant points from the day, focusing on issues that are of particular concern for management of VMB, and also addresses FAQs

PDF 3/16/15
Grape Erineum Mite (5,526KB)

The results of grape erineum mite trials in the North Coast region were recently published in the December edition of CAPCA Adviser.

The article includes a monitoring data collected during the fall migration of erineum mites,  from galls in grape leaves to from grape leaves to overwintering sites beneath latent bud scales.

It also includes results of a preliminary trial evaluating the efficacy of post-harvest sulfur treatments for control of erineum mite populations, in an early-harvested variety (Sauvignon Blanc).

Follow the newsletter link below to access the erineum mite article.

PDF 12/9/14
Vine mealybug (221KB)

The results of the Napa County 2013 VMB Trapping Program are now available as downloadable maps on the Agricultural Commissioner's website.

Vine mealybug (VMB) is a serious invasive pest of grapes in California. In 2012, the Napa Agricultural Commissioner's office, with support from the Napa County Wine grape Pest and Disease Control District, implemented a more intensive VMB survey program, using pheromone-baited sticky traps. All vineyard acreage in Napa County was trapped for VMB at a density of 25 traps per square mile. These trap results are now available on the Napa Agricultural Commissioner's website

For additional information on vine and grape mealybug populations in Napa County, please see the UCCE-Napa Vineyard Mealybugs newsletter

 

PDF 2/28/14
Water limiting (drought) conditions (23KB)

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.  

PDF 1/20/14
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Webmaster Email: cenapa@ucanr.edu