Since its inception in 1964, the grape breeding program of the Arkansas Agricultural Experiment Station has developed and released four seedless table grape cultivars. While the major thrust of the Arkansas breeding program is to develop table grapes for fresh marketing, some effort has been given to improving juice and wine grapes for processing. 'Sunbelt' is the first juice grape released from this program. Sunbelt fulfills the need for a high quality juice and jelly grape that can be grown in areas of the south-central United States where the Concord cultivar cannot be grown successfully. In Arkansas, Concord is not adapted to the central, southern and eastern regions of the state. In those areas, Concord fruit ripens very unevenly, and many berries in the clusters never ripen, thus lowering the quality of processed products. Sunbelt fruit ripens evenly in all regions of Arkansas. Sunbelt originated from open-pollinated seeds collected from Concord grape at Fayetteville in 1968. It was selected from a fruiting seedling field in 1971 and has since been tested as Ark. 1335. Tests have been conducted at four Arkansas locations (Fayetteville, Clarksville, Bald Knob, Hope), and plants have been distributed to several other U.S. states and southern Brazil for testing. Ripens Evenly. Sunbelt is similar to Concord in most plant and fruit characters, differing primarily in its ability to ripen its fruit evenly under high temperature conditions. Plants are moderately productive, yielding similarly to Concord; clusters are small; and berries are blue, large and seeded. Soluble solids and harvest date (Table 1) correspond closely with Concord in areas where Concord is grown. Comparison of yields at the four Arkansas locations shows that Sunbelt has been more productive during the reported test years at Fayetteville and Clarksville than at Bald Knob and Hope (Table 1). The yield reduction at Bald Knob is due to inadequate control of black rot disease in some years, while the lower average yield at Hope is due to the younger age of the vineyard, which has not yet reached maximum productivity. Vines are vigorous and moderately resistant to black rot and anthracnose and show high resistance to powdery mildew and downy mildew, the major diseases in Arkansas. A spray program that is adequate for disease control in Concord is sufficient for this new cultivar. Sunbelt matures its wood early in the fall and has demonstrated good cold hardiness in tests in Arkansas and Kansas, showing no injury at minus 10F. In addition, late bud break (April 2 in Central Arkansas) and late bloom (May 5) help avoid spring freeze damage. In Kansas tests, Sunbelt exhibited sensitivity to 2,4-D, showing injury similar to that for Concord. Juice Quality. Juice quality of Sunbelt was equal to or better than that of Concord in all characteristics (Table 2, 3). In these comparisons, Concord juice commercially produced by a major national manufacturer was used. Sunbelt juice was obtained from grapes grown at the University of Arkansas Fruit Substation and prepared using a procedure similar to that used by commercial processors. Objective analyses were conducted as reported by Morris et al. (1).
