Margaret Worthington, Renee Threlfall, and Carmen Johns
Table of Contents
In 2025, the University of Arkansas Division of Agriculture (UADA) released its first muscadine cultivars following nearly two decades of breeding and evaluation. Muscadines are well adapted to the hot, humid conditions of the southeastern United States, but many existing cultivars were developed in the Deep South and can suffer winter injury in the Upper South. The Arkansas muscadine breeding program was established in 2007 with goals of improving fruit quality, developing self-fertile cultivars with strong productivity, and increasing adaptation to regions with greater winter cold.
The first two releases from the program, Mighty Fine™ and Altus™, target distinct market segments. Mighty Fine™ was developed for the fresh market, while Altus™ was developed primarily for wine, juice, and other processed products.
Mighty Fine™
Mighty Fine™ is a black-fruited, self-fertile muscadine intended for fresh-market production and home gardens. Berries average approximately 11 g, slightly smaller than Supreme (13.6 g), but larger than many perfect-flowered cultivars (e.g., Tara 10 g). Fruit are notable for their outstanding flavor and texture. Soluble solids are consistently high, typically 18–21 °Brix, the skins are tender and edible, and it has a classic muscadine flavor with floral and grape bubble gum aromatic notes.
The cultivar ripens in early to mid-September in Clarksville, Arkansas, approximately one week earlier than Supreme. Berries detach readily and have a high proportion of dry stem scars, contributing to acceptable postharvest performance. In storage evaluations, Mighty Fine™ maintained favorable skin and flesh texture and compared well with established fresh-market cultivars.
Vines are vigorous, productive, and consistently healthy under Arkansas growing conditions. One of the most notable characteristics of Mighty Fine™ is its cold tolerance. During the February 2021 Arctic outbreak, when temperatures fell below –10 °F in Clarksville, vines experienced minimal injury while all fresh-market muscadine cultivars grown at the UADA research vineyard (including Supreme, Black Beauty, Tara, and Summit) were killed to the ground. This performance, combined with strong vine health and balanced cropping, suggests good adaptation to the Upper South and other regions where winter injury can limit muscadine production.
Key traits:
- Self-fertile (perfect flowers)
- Large black berries (≈11 g)
- High sweetness (18–21 °Brix)
- Tender edible skin
- Dry stem scar
- Early-mid season ripening
- Vigorous and productive vines
- Enhanced cold tolerance
Altus™
Altus™ is a black-fruited, self-fertile muscadine developed primarily for wine, juice, and other processed products. Named after Arkansas’s historic wine-producing region, Altus™ was developed as a potential complement or replacement for Noble, the industry standard black processing muscadines.
Fruit average approximately 6 g, substantially larger than Noble (~3.5 g), with thick skins and juicy pulp. The cultivar produces wines and juices with distinctive floral and fruity aromas and an attractive bright purple color. Consumer sensory evaluations conducted by UADA consistently ranked Altus™ wines and juices favorably compared with products made from Noble, with panelists preferring Altus for flavor, mouthfeel, and overall liking.
Altus™ is also notable for its vine performance. Plants are vigorous, productive, and self-fertile, eliminating the need for a pollinizer cultivar. Fruit ripen relatively uniformly, which may improve harvest efficiency. Harvest is approximately, one week before Noble in early- mid September. Like Mighty Fine™, Altus™ demonstrated strong cold tolerance following the 2021 Arctic vortex. In a large demonstration planting at Post Winery in Altus, AR, Altus™ vines had minor spur injury while most Noble vines suffered severe trunk and cordon damage.
Although intended primarily for processing, the larger berry size of Altus™ may provide opportunities for limited dual use in fresh-market sales.
Key traits:
- Self-fertile (perfect flowers)
- Medium-sized black berries (≈6 g)
- Excellent wine and juice quality
- Distinctive floral and fruity flavor profile
- Attractive juice and wine color
- Early-mid season ripening
- Vigorous and productive vines
- Enhanced cold tolerance
Summary
Mighty Fine™ and Altus™ represent the first muscadine releases from the University of Arkansas Division of Agriculture breeding program and provide new options for growers serving both fresh and processing markets. Both cultivars combine self-fertility, strong vine health, productivity, and improved cold tolerance with fruit quality characteristics tailored to their intended uses. For licensing information or a list of licensed propagators, contact agritco@uada.edu.
