Origin: USDA/ARS – New Jersey Agricultural Experiment Station
- High-bush type cultivar.
- Height of bush is 4-6 feet and upright like most high-bush cultivars.
- Ripening date is July 1 in the South Haven, Michigan area.
- Yield has been recorded in Michigan as consistently high, 10-15 pounds per plant.
- Fruit is medium size, 1.8 to 2.1 grams per berry. Berries are light to medium blue and have a firm skin; fruit marketed mainly for the early fresh markets.
- Quality of the fruit is excellent and could be used for fresh market as well as process.
- Harvesting is mainly done by hand because of the early ripening fruit. The berries are produced on long stems and loose clusters, so it is adaptable for mechanical harvesting. Two harvests about 7-10 days apart should complete the Duke harvest, before starting to harvest the Blue Crop.
- Duke is the best cultivar that we have now for early ripening and high quality fruit. It has adapted well in all blueberry growing areas in the United States, and it is a very popular cultivar for all growers. Hardiness Zones 7a-5a.