Kay Gray (Plant patent 4943), released from a private breeding program in Wisconsin operated by Elmer Swenson, is listed as one of the hardiest grapes grown in the upper Midwest.

• 凯灰色（植物专利4943），从威斯康星州的一个私人育种程序中埃尔默斯文森经营获释，被列为在中西部葡萄种植的顽强之一。