Wine grape varieties from warm climate grape growing regions are being imported to California, and tested in the San Joaquin Valley.

It has been estimated that fewer than ten different winegrape varieties account for up to 80% of varietal wines. The San Joaquin Valley (SJV), historically a major producer of winegrapes, has increased the acreage of these core varieties over the past two decades.  However, many of the most popular wine grape varieties were selected from cool climate regions, and thus fail to achieve optimal varietal character in the hot climate of the SJV, even when the best viticultural practices are employed.  Therefore, extension specialists and farm advisors at the Universityof...