What is in this article?:
- Wine grape challenges of the 2010 season
- Overall crop
- Vine mealybug
- Overall conditions were conducive to powdery mildew, but there were enough washing rains and very cool temperatures, so that problems were scattered and light where normal control programs were followed.
- The big concerns on the mind of many growers were new pests.
- The overall crop came in well below last year’s crop and slightly less than average in yield for most varieties in most sites.
The 2010 season presented interesting challenges to growers both long-experienced and relatively new. With the World Series under way, what comes to mind is after several very warm years Mother Nature decided on a changeup. Budbreak began slightly behind average, with weather conditions somewhat rainy and very mild the entire season. One grower mentioned they would rather grow grapes in a hot year as opposed to a cool year, as challenges seem more straightforward. That being said, fruit quality appears to be excellent, with good colors, nice flavors and higher total acids and lower pH. The double-edged sword is a light crop; the early spring rains and continued cool temperatures did reduce cluster development, flower set, and yield. Individual growers sacrifice income, but that should avoid an oversupply of wine as the economy struggles.
Overall conditions were conducive to powdery mildew, but there were enough washing rains and very cool temperatures, so that problems were scattered and light where normal control programs were followed. The early May rain of more than an inch helped reduce stress on vines and might have been part of the reason mite problems appeared light, as with leafhoppers. Compared to last year, this season there was less summer (sour) bunch rot in tight-clustered and thin-skinned varieties such as Zinfandel and Petite Sirah.
The big concerns on the mind of many growers were new pests to the county; light brown apple moth (LBAM) found in the south county in 2009, spotted wing Drosophila (SWD) also found in 2009, and European grapevine moth (EGVM) found in August of this year in east Lodi. The good news seems that SWD doesn‘t damage wine grapes as much as cherries or bush berries. The bad news has been that both EGVM and LBAM require quarantines and compliance agreement programs for growers in affected areas, as well as the added cost of possible treatments. Fortunately, only two EGVM were found and no new finds have occurred.
