- 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 overall crop came in well below last year’s crop and slightly less than average in yield for most varieties in most sites. The cool temperatures delayed harvest to the later side of the long-term average for early varieties such as Pinot grigio, Chardonnay, Sauvignon blanc, and Pinot noir going to sparkling wine production. White Zinfandel harvest began in earnest around Aug. 18, compared to a long-term average of about Aug. 10, and at about the same time as last year, possibly due to the lighter crop this year.
Many of the mid-season varieties sped up in development with a hot spell as harvest began and varieties such as Sangiovese, Syrah, and red Zinfandel were ready about the same time as last year. It seems the traditional core of the Lodi District caught up in fruit development; while the margins of the District to the east and west remained delayed as was most of the coast and foothills. A trace of rain occurred on Oct. 5, but a late-season warm spell before and after allowed rapid fruit ripening ahead of the initial rain of Oct. 17 with about 0.25 inch.
As harvest continued, fall weather turned for the worse; when more than 1.5 inches to 2 inches of rain fell with 30 mph winds, over two days on Oct. 23-24. Although not as bad as last year‘s deluge of 2.9 inches and 40 mph plus winds on Oct. 13, a small percentage of fields were still waiting to be picked. The ground was dry enough from the three-year drought that the rain soaked in fast. Most remaining blocks should have been harvested before significant negative effects of breakdown developed. But it‘s never good.
The 2010 season received above-average rainfall. The last rain occurred on May 27 for a seasonal total of 19.2 inches; compared to 15.1 inches in 2009, 13.6 in 2008 and 12.1 in 2007. However, vineyards need another wet winter to totally recover from the dry conditions. From mid-July on, most daily maximums were below average, but even when daytime maximums were average or higher, the nighttime lows consistently were at or just slightly above record lows each morning with very little dew. Accumulated stress, unusually cool spring growing conditions, and unexplained problems were very evident in farm calls this year. Even with above-average irrigation programs, there was only moderate growth in many vineyards, especially younger vines. And there were many vineyards with late-season berry shrivel or parts of clusters raisining. Often these problems were not attributable to disease, nutrient deficiency, or excessive sun exposure. It occurred across varieties, across trellis systems, and across the district.
Some of these symptoms appeared last year; and as I recall appeared with the dry conditions seen in 2003 and 2004. But the widespread incidence of berry shrivel and cluster collapse was last seen in the 2000 season, when berry and cluster shrivel was rampant across the Lodi region. There are several theories about the problems seen this year, but nobody has the answer and hopefully it will be a long time before we see as many problems, in the meantime maybe we‘ll discover some clues. I think three years of drought had something to do with it (but I could be wrong as I am reminded at home). Other factors to consider are winter, spring, and summer temperatures, nutrient, crop load, and irrigation.