After what felt like a long winter, it seems safe to say that spring is around the corner. I hope everyone’s pruning season is going well, this is the home stretch for sure. I often recommend that growers look for bud damage before commencing final pruning to adjust for buds that may have been killed over the winter. We have not completed our bud assessments at the UVM vineyard yet, and have seen little damage in recent years, given the cold-climate cultivars that we grow. That said, I am a small bit concerned about the low temperatures we observed in late January and February, so I’ll be doing some bud dissections this weekend. Stay tuned.
Pruning and early season sanitation aren’t just horticultural practices, but also form a critical foundation for early disease management on the vineyard. Inoculum for several diseases overwinters on diseased wood, stems/rachises, and mummified berries, and those should all be removed and burned or otherwise destroyed / dumped well away from the vineyard. As the Vermont grape industry is hovering around the 25 year mark, many vines are getting older and you may consider renewing older wood by replacing trunks and cordons where appropriate.
Once dormant pruning is done, it is not a bad idea for vineyards that had Phomopsis or anthracnose or that will be managed organically to receive a dormant application of liquid lime sulfur. I discuss this material in a prior post, and it deserves extended discussion as it is not only very effective in reducing overwintering inoculum, it is also very caustic and among one of the more acutely dangerous pesticides I have ever used. That said, it is very useful and could be a primary tool for the growing field of organic / biodynamic / ’natural’ viticulture.
On that note, expect more material in coming days on these alternative production practices. The UVM Grape program has long promoted an effective, relatively low-input, but certainly ‘conventional’ (I don’t like that word, and prefer to use ‘non-organic’) program for disease and, to a lesser degree, insect management in vineyards. A substantial portion of the Vermont industry, however, is growing grapes under, for lack of a better term, ‘natural’ management programs that take inspiration from organic and biodynamic practices. This is somewhat new practice for me, although I have worked with organic apple systems for over 15 years. The cold-climate grapes that we grow present a unique opportunity to implement such practices, since they are generally more disease-resistant than vinifera and even older French American hybrids. My graduate student, Bethany Pelletier, and I are beginning an intentional focus on supporting this style of production. Expect to see the results of our recent survey in a bit that may help us to define just what ‘natural’ viticulture is, and to hopefully come up with a name and definition we can agree on.
I’d like to end with a plug for growers to register to attend the VitiNord 2022 conference, which will be held in Burlington December 4-7. This is a big deal. VitiNord is the world’s premier grape and wine conference focused specifically on cold climate production. It alternates every three years between Europe and North America, and we are truly honored to be hosting it. Registration is open now, and is discounted at least until the end of the month. Thanks to a grant I procured from the Vermont Agency of Agriculture, members of the Vermont Grape and Wine Council receive a further discount, but those are limited, so plan on booking soon. To join the council, contact them here.
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