Cold Climate Viticulture
-excerpt from “What are Northern Grapes” by William Shoemaker, University of Illinois
Grapes, as food and drink, have been integral to human culture for thousands of years, particularly in the Mediterranean and Middle East, so it might seem a little unusual to describe grape cultivars as ìNorthern Grapes.î But the work of the Northern Grapes Project focuses on an important new development in wine grape cultivar selection — the emergence of new varieties of wine grapes with much greater cold-hardiness than other wine grapes. Where did these new types of grapes come from? Are they really different? Why do they deserve the attention they are getting?
History and genetics. Wine grape cultivars are historically derived from Vitis vinifera, the grape species native to Europe and western Asia. These cultivars, such as ëChardonnayí, ëRieslingí, and ëMerlotí, developed over thousands of years in Europe and the Middle East, becoming important elements of their economies and culture. In recent centuries they have spread globally to form important wine industries in many other regions, including mild regions of North America.
But many other species of grapes are found around the world. This is particularly true in North America, where more than 15 distinct wild species of grapes are found. The Europeans, quite familiar with grapes, took interest in these wild species as they explored the newly-discovered continent of North America. Their interest led them to export some of these grapes back to Europe. Unfortunately, these grapes gave rise to pest problems that were inadvertently exported with the grapes. This was particularly true of grape phylloxera, an insect that feeds on grape root systems. Because European grapes are very susceptible to phylloxera, the grape industries of Europe began to decline in the 1800ís due to an epidemic. The French eventually learned to crossbreed V. vinifera grapes with North American wild grape species, which imparted genetic resistance to phylloxera in the resulting seedlings. In doing so, they established a model for interspecific breeding of grapes, or creating hybrid grape cultivars.
Eventually, another method was developed to address the phylloxera epidemic in Europe – using North American grape species as grafted rootstocks. However, interspecific breeding of grapes to create new wine grape cultivars continued into the middle of the 20th century in France. Many new cultivars of hybrid wine grapes were created, some of which were introduced to North America. These hybrid cultivars, such as ëChancellorí and ëSeyval Blancí, became popular with grape growers in the eastern United States because they were more hardy and pest resistant than vinifera grape cultivars. Slowly, a hybrid wine grape industry began to emerge.
Full article can be found at http://northerngrapesproject.org/wp-content/uploads/2012/06/2012May18Newsletter.pdf