Organics in Eastern Viticulture
Few crops are woven into the fabric of human history and mythology as intimately as grapes. For as long as people have been cultivating plants, we have been growing grapevines and adapting them to the lands we farm.
Grapevines can be a challenge to grow in the humid climates of the East and Midwest. Diseases are a constant concern and if left unchecked can damage a canopy or crop quickly. For some pathogens, organic control measures are limited. That said, there is a clear place for “organics” in Eastern Viticulture.
At the foundation of any good disease management program are cultural controls. All grapes will benefit from a well managed (uniform) canopy and fruit zone, which allow for light and air penetration. Sunlight and air-flow are the most effective disease control measures, and a vineyard that is set up to maximize their benefits is set up to succeed - leaf pulling and fruit thinning are essential. Healthy plants are more resilient; a good fertility program is an important part of pest and disease management. Genetics also play an important role - many hybrid and native grape cultivars are less susceptible to disease pressure and may make good additions to vineyard or winery programs.
Many of the mainstay tools of modern viticulture are approved for use in organic production; oils, sulfur, copper, potassium bicarbonate and hydrogen peroxide are all highly effective at preventing and/or controlling various fungal pathogens. There are also a number of relatively new, biologically-based fungicides that are proving to be effective alternatives to their conventional counterparts.
A key point in favor of using organic materials to prevent diseases such as Powdery Mildew, Downy Mildew and Botrytis is the continual development of pathogenic resistance to conventional fungicides. Fungicide resistance is an issue in many crops and in many areas of the country. Organic and biological materials offer a rotation away from conventional chemistries, ultimately working to slow or potentially prevent the evolution of resistant pathogens. In many cases, organic and biological control options are as effective as their conventional counterparts for the practical intervals required by Eastern viticulture.
A wide range of insects and mites are either direct or indirect pests of grapevines. In the same way that canopy architecture is the grower’s number one tool against diseases, scouting is the foundation of a solid pest management plan. Pest pressures will vary more in their intensity and timing from site to site and year to year than disease pressures… for this reason, vigilant scouting is necessary to stay ahead of pest outbreaks. Organic insect controls, while effective, often have a relatively short active period meaning that the timing of a given treatment should be fairly precise. A good rule of thumb is to treat for diseases preventatively, but to treat for insects and mites when they are present. Understanding the life-cycles and habits of key vineyard pests is essential for achieving good control and a clean crop.
During the course of a season any number of issues can arise in the vineyard. If you encounter a challenge not outlined in our guides please feel free to call and our viticulturist can work with you on a solution.