Grapes a valuable asset for US growers

Grapes are the highest-value fruit crop grown in the United States.

More than 70 per cent of the grapes grown are used in wine. As wine grape production expands to new areas in the US, growers need grape varieties suited to their growing conditions, which can differ environmentally and economically from traditional regions.

Growers also need varieties that are more resistant to common pests and diseases. Wine producers are interested in new varieties they can use to create new wines and expand sales.

To find the best grapes for US growers and wine producers, researchers at land-grant universities across the country are testing the performance and resulting wine quality of different grape varieties, including traditional, lesser-known, and new varieties.

Researchers supported by USDA’s National Institute of Food and Agriculture also set up a database to store information on the characteristics of each variety and shared their findings with the industry through newsletters, farm tours and websites.

This information is improving the economic viability of and respect for grape growers and wine producers nationwide.

As part of this collaborative project, researchers are growing different kinds of grape vines at more than 20 test sites across the country.

Researchers are collecting high-quality data and compare results. After harvest they analyse grape colour, acidity and other qualities.

Establishing vines at a wide range of sites is helping distinguish how genetic factors, environmental conditions and management practices influence grape yield and wine quality.

For example, at the University of Nebraska, researchers are evaluating whether reducing crop size improve wine quality. Other scientists showed the effects of grapes’ nitrogen nutrient supply on wine flavour.

Researchers have also identified grape varieties and management practices to prevent damage from cold weather and grapevine diseases, both of which affect many American grape-growing regions.