Toxic fungicides, pesticides, insecticides and herbicides are routinely used in large quantities and applied most frequently and intensively in the "fine wine" growing regions of Sonoma and Napa as well as in Lodi, as you can see in this map below from the California Dept. of Pesticide Regulation's most recent report showing the active ingredients applied to wine grape vineyards in 2016.
(The 2017 report is due out in June).
While sulfur is the most frequently applied active ingredient, glyphosate, copper and oils are commonly applied.
The 2 percent of vineyards in California that are organic may use sulfur, copper and oils, but the vast majority of these materials is used in conventional vineyards (98 percent of vineyards in California).
Despite the widely publicized growth of industry sponsored sustainability programs, pesticide use is increasing, not declining, the report states. It says (page 119), "The long term trend over the last two decades is an
increasing area treated for all pesticide types except for sulfur which has tended to fluctuate more
annually (Figure 37)."
Copper, this chart suggests, is used on 400,000 acres of grape vines.
California has about 550,000 acres of planted wine grape vines.