Tour of Southern Vermont Vineyards 7/30/2014

by Terence Bradshaw

Doug McBride of Brook Farm Vineyards recently invited me down for a consultation at his farm in Proctorsville, VT. After several weeks (months?) of trying to make it happen, we agreed on a date, and he indicated that some neighboring growers were interested in participating. I asked Doug to set up an itinerary, and he pulled together a great group and a rewarding tour schedule. The focus was on problems that new growers are experiencing in their vineyards, rather than successes.  All of the tour hosts were very open and accommodating of myself and other participants looking over their sites, nothing was hidden.  Thanks Doug for making this visit happen!

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We began our tour in Doug’s vineyard. Like all of the others that we saw, he planted in 2009. Vines were generally under-vigorous, but many had been adversely affected by last winter’s extreme cold temperatures. We saw Foch vines in particular that were damaged, with many blind spots on cordons, and shoots that had emerged from secondary or even tertiary buds. Doug pointed out some abnormally-shaped leaves on a few vines that appeared to me to be representative of glyphosate (Roundup) injury. We discussed best practices for applying herbicides, especially systemic ones. in the vineyard: apply before bud break, use a shielded spray boom, and avoid drift. In 2011, Brook Farm Vineyards was flooded with gravel during Tropical Storm Irene. In most of the vineyard, this gravel was removed, but some vines still had this layer of ‘mulch’ at the bases, and it appeared to do a decent job preventing weed growth. I don’t recommend that growers seek out 100-year floods to apply gravel mulches, but this was a unique situation that hasn’t seemed to harm the vineyard in the long-term.

We did identify some poorly-performing vines with low vigor and a lot of winter damage. These were located in a low spot in the vineyard with poor soil drainage, which highlighted  the need for excellent soil water drainage. This characteristic of the soil is the most important site consideration when choosing to grow grapes. If you haven’t yet planted but are considering it, I strongly recommend that you consider installing drainage tiles on any marginally-poor draining land. Some vines, especially in the wetter area, showed some crown gall symptoms. This bacterial disease is systemic in affected plants, and cannot be managed through spraying or other common disease management techniques. Disease symptoms are expressed in vines with cold damage on the lower trunks in particular. Best management is preventative: choosing an ideal site; ensuring adequate air and water drainage; and selection of cultivars hardy to the cold temperatures typically experienced in the vineyard; and selection of disease-free planting stock. Galls form at wound sites and may choke out the vine- affected plants may be cut back below the site of infection but the disease may return in future season.

We saw some disease in the vineyard, primarily phomopsis and a little black rot, which can be managed with a modest fungicide program. Doug has been spraying the vineyard with a boom sprayer, and disease incidence was low and appeared to be clustered in certain areas of the vineyard. He mentioned difficulties with spraying while maintaining peace with neighbors, a concern I am well-aware of since the UVM vineyard abuts a residential neighborhood. The best times to spray to avoid drift and ensure good coverage tend to be in late evening though early morning because wind speeds are generally lowest then, which means waking up neighbors with associated noise. Delaying spraying until later in the day makes the activity more visible, and often means spraying in the wind. Each grower needs to assess the best spray conditions for their site and neighbors, and often a compromise must be struck. I explain to our neighbors the need to spray during low-wind periods, and keep them alerted to when I may be spraying ahead of time so that they may adjust their sleep schedules or turn on white noise as needed. I suspect that in Doug’s case, he had some areas of poor spray coverage due to wind or other factors that allowed for disease development. Thankfully, it was not widespread in the vineyard.

We next visited Newhall Farm vineyard, a small planting located in Reading. The vineyard was small, about 1/2 acre, and initially planted with aesthetics as a primary consideration. This included terracing the hillside with bulldozers prior to vineyard establishment. This sitework resulted in two problems: soil compaction and removal of topsoil. As a result, the vines were relatively low-vigor, and some nutritional deficiencies were observed. We discussed subsoil tillage that may help loosen the compacted soil, and the need for collecting soil and petiole samples annually in order to address nutrient needs. While generally small, vines were well-balanced overall, and good canopy management had been performed to expose clusters to sunlight and direct shoots downward.

Possibly one of the most interesting vineyards that I have visited in Vermont was at the home of Tony Antinori. I suspect that Doug planned for the tour to end at Tony’s in order to highlight the uniqueness of his management style. I have often stressed the importance of maintaining a modest, protective, IPM-based fungicide program in vineyards to manage diseases that will decimate crops in virtually every season. Where   growers have attempted to manage vineyards organically, I have seen complete crop losses, often in the third or fourth year after planting. When grapes are planted on sites where grapes are at most an incidental wild vine here and there in the landscape, disease and insect inoculum often start out low. This allows the vineyard to be established without sprays for a few years, but as the vines grow, so do levels of disease, such that right around year four, all of the fruit are lost, most often to black rot, as well as phompsis, anthracnose, downy mildew, and powdery mildew.

Tony informed the group steadfastly that he “just won’t spray, it’s not going to happen.” Given that scenario, he needs to manage his vineyard differently than I generally recommend in order to find success. Tony is meticulous about hand-labor in his vineyard: Doug McBride stated several times during our visit that “no one works harder in their vineyard than Tony.” Diseases leaves and tissue are hand-pulled during the growing season and burned to reduce inoculum. Vines are trained onto a high (as in, you can walk under the whole canopy) trellis/arbor that improves airflow and moves the canopy above leaf litter that may serve as inoculum refuge. The soil under the vines is double dug by hand each year and incorporated with Tony’s own compost, resulting in some of the finest weed management I have seen in a vineyard in this state. The vineyard is small, and truly a work of art.

That said, there are disease issues in the planting. The vineyard consists of two small blocks on either side of the road, and the vines nearest his house were cut back to three-foot high trunks in spring 2014 because of fungal issues on the canes and older wood. I observed plenty of phomopsis in those vines, but the newest leaves that emerged were relatively free of disease symptoms. Fruit in the vineyard across the road were infected with black rot, phompsis, and anthracnose, and those diseases as well as powdery mildew and downy mildew were present on the foliage. Given the size of the vineyard, I wouldn’t expect it to be a significant income-producing enterprise, even if diseases were managed perfectly. But Tony obviously finds much satisfaction in his efforts in it, and I applaud him for sticking with it. That said, I cannot recommend his management style over the long-term for anyone who intends to harvest a commercial crop from their vines. Tony’s experience will be interesting to follow in future seasons.

Overall, this was an enjoyable tour, and I again thank Doug for pulling it together. I think I helped the fifteen attendees gain some knowledge on sustainable viticultural practices, and I certainly learned a lot over the course of the day.