As in much of the state, acreage of wine grapes in Sacramento County increased rapidly during the 1990s. According to the 2013 Sacramento County Crop & Livestock Report, there were 31,522 harvested acres of wine grapes, with a value of $141 million dollars - the leading commodity in Sacramento County.
The main varieties growing in Sacramento County are Chardonnay, Cabernet Sauvignon, Merlot, Zinfandel, Sauvignon Blanc, Syrah, and many growers have planted blocks of Pinot Gris, Pinot Noir, and Petite Sirah. Unlike pears, wine grapes are produced throughout the southern part of the county. Although there are no large wineries in Sacramento County, there are some small wineries and tasting rooms. Sacramento County contains a portion of two crush districts: the Lodi district, east of Interstate 5, and the Clarksburg district west of I-5.
Below are articles and links related to several locally important vineyard problems. Also visit the UC IPM Pest Management Guidelines.
Grapevine red blotch disease is a new virus disease that has no known vector (as of Jan. 2015). The disease occurs in some vineyards in the northern San Joaquin Valley. Rhonda Smith, viticulture advisor in Sonoma County wrote an excellent article on her Viticulture web page: http://cesonoma.ucanr.edu/viticulture717/.
Sugar accumulation disorder (SAD) causes poor berry coloration and low sugar accumulation; it is triggered after veraison. SAD-affected fruit typically have lower pH, berry weight, and Brix compared to normally developing fruit. Berries may contain up to 70-80% less sugar than healthy berries and are often shriveled. Click here for photos and a summary article on SAD.
Powdery mildew and bunch rot pose problems each year. For powdery mildew, dusting and/or spraying with sulfur and/or any of a number of fungicides is required, although some varieties are more susceptible than others. To see recent reports of Doug Gubler's powdery mildew trials, click here. For bunch rot, control strategies are usually necessary on tight clustered varieties.
Vine mealybug (Planococcus ficus) can be found throughout the region, and several insecticides are available for its control. Click here for a 2012 newsletter article that discusses current vine mealybug control methods. Other pests include grape leafhopper, spider mite, and omnivorous leaf roller (OLR).
Canker disease is a serious problem that affects the long-term viability of vineyards. Late pruning (February to early March) is recommended but is often not practical. Fungicides are available to spray immediately after pruning, which can prevent most infections. Click here for a 2011 newsletter article that discusses canker disease.