Disease and pests are not yet much of a problem in the northern grape growing reaches. Temperatures are still the key concern as spring progresses.
Dana Grande, viticulturist with Jordan Vineyard and Winery in Healdsburg, Calif., has heard reports of frost damage and injury to the vines, but it may be too early to know the full extent of the damage.
“We've had a bit of leaf burn due to cold injury, but fortunately, our vineyards without frost protection were pruned late this year. We began the practice of double pruning in order to limit the spread of Eutypa and other wood fungi, and we've happily experienced the added benefit (at least this year) of late bud break.”
Other than the uncertainty of weather, things are just about par, according to Rhonda Smith, UCCE Sonoma County farm advisor in Santa Rosa, Calif.
“Mildew sprays have been applied,” Smith says. “In some vineyards, grape mealybug and European fruit lecanium (EFL) scale can be seen on the spurs or canes. Portions of these populations are just starting to move to the shoot. Some growers are applying Stylet oil. Most are not concerned about grape mealybug at this time and are waiting to see what the next generation's population does. A few people may spray for grape mealybug in a few weeks.”
Thiolux has been in short supply due to a plant explosion, according to Smith. “For many growers, the first applications for mildew have been with Stylet oil when they would have preferred to use a micronized sulfur spray,” she says.