Wines & Vines Interview: Bill Petrovic

The verdant expanse of San Bernabe Vineyards shows the scope of Petrovic's responsibilities as vineyard manager. Petrovic doesn't believe that stressed vines produce better fruit. Photos: Courtesy DFV

Bill Petrovic is manager of DFV Wines' large San Bernabe Vineyard in King City, Calif., where he grew up. He has worked at San Bernabe (pronounced san behr-NAH-beh) for 29 years. Since the Indelicato family, founders of DFV, bought the rolling southern Monterey County property in 1988, Petrovic has had the opportunity to reshape much of it, and put into practice what he has learned about Central Coast viticulture over a lengthy career.

Managing a property of 12,000 acres, of which about 5,000 are currently planted to winegrapes, Petrovic (PET-ro-vitch) has experienced on a broad scale what many growers only see in microcosm. San Bernabe has its own AVA designation, and grows an assortment of cool- to warm-climate varieties, notably Riesling, Chardonnay, Sauvignon Blanc, Pinot Noir and Merlot. Some of each year's harvest goes into DFV Wines' own brands such as Monterra, Irony and King Fish, while a large proportion is sold as grapes or made into bulk wine on the property to sell to other brands. Claude Hoover is president of the vineyard.

Bill Petrovic has overseen San Bernabe Vineyards since 1978, 10 years before its purchase by the Indelicato family.

Petrovic received a bachelor's degree in psychology from the University of San Francisco, and traveled in Europe for a year before starting work at San Bernabe.

W&V: Why and how are you redesigning the water system at San Bernabe?

Bill Petrovic: The entire vineyard at one time was under sprinkler irrigation for both frost control and irrigation. We now have independent mains for drip and sprinkler, due to not being able to drip until June 1, which is the traditional end of frost. With the new design, we can drip or fertigate basically independent of the frost system.

Due to the increasing cost of power, and the political and public emphasis on water, we have initiated a lining project for our canals and reservoir system, which is composed of 14 miles of canals and 18 reservoirs. Analysis of our yearly extraction and application showed a huge loss to percolation. This year, we focused on the areas of the greatest need, and sealed one reservoir and approximately 5 miles of canals. Currently we have six lined reservoirs, five being from a previous install. The water savings are already apparent. We have replaced approximately 6 miles of additional canal system and high-energy-demand pumps with 36,000 feet of 21-inch mainline and 30 high-efficiency pumps. This conversion should be completed by November of this year.

W&V: What's the basis for water management decisions?

Petrovic: Design of the water system really needs to start at the rootstock level. Over the years, we have tried many different rootstocks for the traditional reasons: vigor and resistance to soil-borne pathogens. There is a significant water use difference among rootstocks. Saltcreek and 1103P, which are both deep-rooted, use a minimum of 50% less water than 5c or 101-14, for example. As an added bonus, we do not see the vine stunting in the Central Coast region-which I believe is a combination of cold damage and salts-in these rootstocks.

Water is one of the focus points of sustainable farming practices, both the control of too much-floods, runoff and erosion-and on the other side of the coin, the lack of. We have, through the use of cover crops, tillage practices, road design and catch basins, addressed the issue of abundance for many years. The conservation of water in both a social and economic context is coming to the forefront. To keep farming, we must sustain both the source and the economic model in relationship to water.

W&V: Which trellis systems do you prefer at San Bernabe?

Petrovic: I am in my 29th year of this business, and I have a bit of a comical outlook on trellis systems. Many of the contracts of the '70s had penalties for fruit exposure to the sun, and that included reds. California reds were considered vegetative and thin. Throw in unexposed fruit on vines the size of a redwood and then Brix levels of 22° on reds, what does one expect? The next faux pas was the feeling that weak, stressed vines make the best wine. In reality, it was not weak, stressed vines, but the exposure of the fruit to ambient sunlight due to small canopies. In California, with fertile new soils, small canopies are not the norm; trellis systems are the way to achieve the same light frequency as vines in traditional European vineyards.

Fruit exposure is a question of not only the variety, but also the winemaking style of the individual wineries. Sauvignon Blanc is a classic example. Some wineries want exposure, for a more rounded and fruit forward flavor and others want a thinner, more mineral style. We have found that moderate exposure is the best for both reds and whites. We do not leaf pull on the south side of vines except in trial work. All the reds and some of the whites are leafed on the north side. People are beginning to realize that over-exposure or full exposure actually detracts from color in red varieties.

The classic original two-wire California sprawl is still an excellent system for many varieties, and is my second favorite after the Smart Dyson system. The real essence of the Smart Dyson system is that we can have higher density by decreasing the distance between vines as they are farmed up and down, are equal in spur capacities to a 7- or 8-foot spacing in 5 feet and still maintain a vine row width of 9.6 feet. Narrow-row vineyards go hand-in-hand with high cost, low resale and low reliability equipment, higher mildew and rot pressure and higher accident rates. It has never made sense to me to plant low vigor rootstocks so one can have high density.

The one trellis system we will never use again at San Bernabe is the split canopy or quad system. It does not lend itself to efficient, clean mechanical picking, and pruning costs are higher than a vertical system. We have spent a fortune in design and redesign, and finally have decided to hand pick quads, due to fruit loss from both juicing and fruit left behind.

W&V: Are you practicing deficit irrigation?

Petrovic: Remember that most traditional winegrowing regions in the world have summer rains and high annual rainfall. We have neither, and our summer irrigation emulates the summer rains of other regions.

Deficit irrigation should be called managed irrigation. We applied only 3.8 inches of irrigation water last year from June to harvest in our reds, due to high rainfall in the winter months and a substantial rain in June. We use two different types of soil moisture probes, visual inspection and the best tool of all, a shovel. We try to establish a canopy balanced to the fruit load, providing enough leaf mass for ambient light by mid-June, and then try to maintain the canopy until harvest with no real additional growth.

W&V: Does San Bernabe mechanically prune?

Petrovic: Due to high Eutypa pressure, we do not mechanically prune, except in one trial block, and that is actually hand pruned to simulate machine pruning. Many of the original blocks died of Eutypa, due to previous mechanical pruning. Lose a spur, lose a vine, it is as simple as that. Our old blocks, within three years of mechanical pruning, were dying of Eutypa.

We have elected to hand prune, hand shoot-position, cluster thin and leaf pull due to the lack of efficient and nondamaging equipment. I looked at a leafing machine, which was also dropping crop, and the crop loss exceeded the cost of hand leafing by 3 to 1. We sometimes forget that we are in business and need to have a business model, which follows budgets and spends monies in the correct categories. We have elected to use chemical weed control and mechanically pick so that we have monies left over for cultural practices, which truly make a difference in wine quality.

W&V: Does San Bernabe mechanically harvest?

Petrovic: We have since the inception of the vineyard. Currently 90% of the fruit is machine harvested, and just the young vines and varieties which may have a quality issue are hand picked. If wineries have a desire for hand picking, it is available at the variance between the cost of machine picking and hand picking. The real key to machine harvesting is the time-to-winery on white varieties and temperature of the fruit. We pick in the cool of the late night and morning on the whites, and the majority of the fruit is crushed on site at the Delicato Monterey Winery.

There can be spur damage on the vines, especially with bow rod machines, but the vines are active and exude fluid in the wound area, eliminating the Eutypa spores from the wound. Both trunk shakers and bow rod machines are used, and in easy-picking varieties the shaker is favored due to no mechanical issues in the spur area. In hard-picking varieties, it is a toss-up, due to having to use rods in the spur area on the trunk shakers. Long term, machine picking will be the norm due to labor constraints. Any hand picking is by the hour, as a piece rate crew can do more damage and leave more fruit than any machine I have ever seen.

W&V: What's your approach to pest control, specifically of mealybugs?

Petrovic: The industry has to have constant vigilance on any pest which can affect it, as there is constant interaction between different growing regions via vehicles, trucking and equipment exchange. The proposed quarantine in the 2005 season is not the answer, as the pest is widespread. The grower has the obligation for identification and control. We actively field monitor, and have the findings analyzed for species at the lab.

On the issue of spray materials for vine mealybug, the evolution to softer and more sustainable materials will come down the road. There is not a long-term issue with mealybug, as long as the grower is on top of the vineyard.

W&V: Is labor an issue?

Petrovic: Currently we are fine, due to having a comprehensive wage and benefit package for our permanent staff. Our seasonal work is through several labor contractors, and we pay above the minimum and try to make every day a full day. With the price of fuel, day care, the general cost of living, we feel a moral and ethical obligation for the people to have a full day of work.

Owl boxes are one sustainable method of keeping pests down at San Bernabe.

I have made references to sustainable farming throughout the interview, and labor is a huge part of the continuation of farming. We are taking an active role as part of the farming community to promote agricultural-related courses in the local junior colleges.

Having mechanical systems which truly can prune and do other cultural practices in the vineyard is another form of sustainable farming practice. We continue to test and trial machinery that has the potential to make an individual more productive or eliminate hand labor in one area so the labor is available for another practice. Labor is an issue that must be managed for agriculture to sustain itself into the future.

W&V: Why do you continue to enjoy farming?

Petrovic: Ultimately, it is the people one has the privilege to work with. The staff at San Bernabe is wonderful, and in general good and competent people man the wineries we deal with and the vendors we buy from.

After the people element, it is the diversity of the problems and solutions that is attractive. Farming is not boring, and the scenery changes constantly. There is a sense of history and accomplishment, and also failure, over the years that one would not have in a normal job. Every day is not a duplicate of the past.

San Bernabe is unusual in that it remains family owned. There is a direct contact between the family and staff on a daily basis, not only on the farming end, but also the winery end. It's unique in modern corporate structure, in that many decisions involving risk can be made on the spot. The Indelicato family has been in the farming and wine business for 80 years, which is a statement on sustainability in itself. They are committed to the continuation of the vineyard on a long-term basis. I have always said working at San Bernabe is as close as one can get to farming for yourself.

"Why farm?" ends up being a very complex and simple question. Living in a rural environment, working predominantly outside, being part of the solution and decision process on a family scale and working with a staff that is appreciated by ownership, are some of my answers. Pretty good deal, if you ask me.