The 2015 Harvest came to a close by the second week of October. Harvest began on the earliest date that most anyone can remember. It is an interesting year to say the least, but there have been previous harvest starts in July. Let’s look back on some local observations from the recent past. Checking some of my notes; Zinfandel for red was picked in August in 2001, 2004 and 2007; at 24° to 26° Brix, compared to usual harvest dates around mid to late September for red programs. A Chardonnay clone trial was harvested on August 17 in 1994. In my 29 years as Farm Advisor, my impression has been that Mother Nature follows her own schedule irrespective of what we plan or do.o.
The 2015 season did start out with budbreak a full three weeks ahead of average on February 28, but the previous early record start was on March 1st in 1997. The cool April and May slowed crop development enough to put the harvest about 10 to 12 days earlier than long term average. And a surprise hailstorm caused some scattered but severe damage in the area west of downtown Lodi between Highway 12 and just north of Turner Rd. A few small areas of damage also occurred to the north and south of Lockeford.
June tended to be warmer than average, but July was average or slightly below average for temperatures. Some color in Zinfandel occurred as early as June 23 compared to the average date around the July 4. After veraison the weather heated up with a few 100°F days (38°C in Australian), but returned to more average maximums as harvest ramped up. The season ended with a total of 14 days when the maximum temperature for the day reached 100°F or above, versus an average total of about 17 days. The Growing Degree Day (GDD) accumulation as of October 1st was just slightly above average for this point of the season, with about 3200 GDD accumulated.
A recent visit to Alabama reminded me why California, and Lodi in particular, is a good place to grow grapes. But on returning, everything here irrigated or not, looked pretty stressed compared to the green countryside back East.
The positive aspect of weather this year is that the heavy December rains and a couple of well-timed spring rains mitigated the below average total rainfall and dry soil conditions, which developed over the last four years. This year’s total rainfall of was 13.2 total inches in the North County, which at 80% of average is better than initially expected. The majority of this total (9.2 inches) came early in the Fall and Winter months from October through December. This helped to recharge the lower root zone and to alleviate some vine stress, at least early in the season.
In most years, mornings will begin with significant dew on the windshield. This year with warm days, cooler than average nights and many windy days there was little morning dew. At his point in the season (as was the case last year) I counted less than a handful of days when there has been morning dew present. Maybe as evidence the wild fires that burned coastal and foothill areas proved difficult to get under control.
Added to low humidity there were many windy days through April, May and June, not as much as last year but quite a few through the spring and early summer. These windy days did help keep temperatures down and may be part explanation for the dry mornings. Similar to last year, conditions were good for powdery mildew (PM). Although problems were scattered and not as bad as feared, it was relatively easy to find PM, as disease pressure was severe from April on.
- If the weather stays dry, post-harvest irrigation to help maintain soil moisture is okay until rains are steady.
- Little to no nitrogen should be applied now, but potassium (now or early next year) is okay. It won’t “move” like nitrogen. To get full benefit of compost, it needs to be disked in.
- Make a note of any problem weed species that may be increasing.
- Mark any vines with excessive red leaves and/or leaf roll for monitoring of fruit quality next year of for possible removal before then.
- Renew your Irrigated Lands Regulatory Program permit/membership and stay up to date on implementation of Waste Discharge Requirements (WDR) for 2015.
- Update your air pollution mitigation plan if you have 100 acres or more in a single vineyard.
- Also, review your pesticide use reports and get everything up to date.
- Check for locations near riparian areas, trees and other bird roosting sites for VMB. Focus on these areas next spring in any VMB control program. Lorsban (chlorpyrifos) is still an option for a late winter application, but be careful of sprays before any late winter/early spring storms, especially near natural drains and waterways.
- Gophers, voles and squirrel activity are common this time of year and may deserve attention with baits, gas cartridges, fumigant pellets (usually better in spring), trapping, shooting, or a combination of several of the methods. Remember ground squirrels are fair game, tree squirrels require a depredation permit. Owl boxes can help stabilize rodent populations, but do not control them.
Mite problems flared somewhat in the last part of the summer, but still occurred rather scattered and inconsistent, and light considering the dry soil conditions. The good soaking rains from October to December I think helped alleviate many problems that could have been a lot worse.
Four dry years have taken a toll on older vines. Interestingly, three out of the four very dry years produced two big crops in 2012 and 2013. There is a fair amount of dieback and dead vines, especially in Old Vines (30 year plus). If we get a halfway “normal” Fall/Winter vines should stabilize and maybe recover somewhat.
Chardonnay was ready for harvest in the third week of July. Some small plantings of German varieties in the Victor area were also harvested as of August. Harvest got fully under way about July 24 with Pinot grigio, some Sauvignon blanc, some Muscat selections and some Pinot noir for sparkling wine. The first Zinfandel berries with color began to show on June 23 and some vineyards for red programs were at 28 Brix by August 20.
Other mid-season reds were also ready to go with some Pinot noir approaching 24° Brix in late August! The crop was about average across varieties, but ranged from about 20% below long term performance to well above average for young vines. Exceptions on the heavier side might be Chardonnay, while exceptions on the light side of average, for old vines and less vigorous vines.
Strong shoot growth early in the year from good soil moisture may have helped keep berry and cluster size close to normal although generally slightly below average. Cluster counts were mostly average, in many cases as good as last year, but cluster size and set varied by variety and location. Some of this variability possibly depends on the erratic temperatures during a rapid bloom period, but mostly from four years of drought and the two of the three previous seasons with record crops. Overall berry and cluster size may be smaller this year as extremely dry conditions prevailed during early spring development of berries. Fortunately, Sour (Summer Bunch) rot was very much less than last year and almost nonexistent.
A new concern, or actually an old one that seems to be more of a problem as grape varieties are now clean of most common Grape Leaf Roll associated Viruses (GLRaV), is Grape Red Blotch associated Virus GRBaV). It doesn’t seem to be as severe as some of the traditional problem viruses, but in some varieties and some sites does seem to inhibit sugar accumulation. The frustrating part of GRBaV is we don’t know if there are pest vectors, where it came from, how long it has been around or if there are different strains. For more information see this National Clean Plant Network’s fact sheet or visit the UC Integrated Viticulture site HERE.
Market demand continues to be positive if not great, and improved for most varieties such as Cabernet sauvignon, Petite sirah, Muscat varieties, Red zinfandel, and even Merlot, among others. Many other varieties such as Chardonnay and Pinot grigio (gris), Pinot noir, Sauvignon blanc, still seem to be in good demand. But at the same time there were a few scattered blocks that were not picked either from low prices offered or difficulty maturing after the rian on October 1 (about 0.2 inch).
The mini-boom in planting new vineyards and the replanting of old blocks has slowed. The problem of the general economy and its sluggishness remains and may affect market demand, even with wine consumption still growing. Local growers overall are still in a relatively good position compared to most other sectors of the state and national economy, maybe because everyone needs a drink.
Vine Mealy bug is still spreading through the county, so be aware of any new infestations, often indicated by sooty (black) mold and honeydew staining on bark of the trunk or cordons, or excessive honeydew and waxy secretions in clusters, on spurs or along cordons. A high degree of ant activity in and around vines can also indicate problem spots. Good places to focus on a first look are where birds tend to perch or roost. It may be the mild and dry winter, along with the early budbreak increased VMB movement earlier. It does appear the materials available for control are working, but just have taken longer to fully suppress active populations. At this point there don’t appear to be any control problems, but be on the lookout.
The Light Brown Apple Moth (LBAM) continues to expand its territory in the south County around Manteca since it was found in 2009. It is very similar to Omnivorous Leaf Roller (OLR); somewhat in appearance, also in the number of host crops, and definitely in damage; but also in control. It does appear in some areas of the state LBAM is showing some effects of control by native beneficial insects. Learn more about LBAM on the UC IPM website. A new invasive species of concern for many crops is the Brown Marmorated Stink Bug (BMSB). First spotted in Stockton a couple of years ago, may have been identified just west of Lodi recently. The Ag Commissioner’s staff is working hard to monitor both of these threats as well as several other invasive species affecting other crops.
Some general observations (no data) come to mind after four years of drought conditions:
- More evidence of trunk canker diseases and vine dieback.
- Fewer weed problems
- More concern of apparent early and increased Vine Mealybug (VMB) activity
- More over all vine stress on vines young and old and more potassium “deficiencies”
This year an average or slightly below average grape crop may help maintain a balanced inventory in the wineries and slow any potential price drops. For growers and most other businesses, costs and regulations continue to increase, but more recognition of Lodi affordable and quality oriented value wines quality can help sustain operations. There are lots of unknowns and uncertainty in the world, but Lodi and San Joaquin County are in a good position to continue the tradition of quality wines of value.