Origin and Description

In 2001, Georgia Dawn™ was designated as advanced seedling 01-28 in Griffin, GA, originating from a cross of ‘Star’ × ‘Bladen’ made in 1998 by D. Scott NeSmith (Lyrene and Sherman, 2000; Rooks et al., 1995). In 2003, it was designated ‘TH-819’ (USPPAF) and was propagated for additional testing. Georgia Dawn™ is being released for commercial use. The new cultivar has an estimated chill requirement of 300 h or less (less than 7 °C). It is a very early-season southern highbush with medium to medium–large size fruit (1.5 to 1.9 g/berry). Berries are medium to light blue in color and have a small, dry picking scar. Berry flavor is very good and firmness is good. Georgia Dawn™ plants are vigorous and have an upright bush habit with a narrow crown. Propagation is easily accomplished using softwood cuttings; however, there have been some difficulties with in vitro propagation. Plants are self-fertile, but planting with other southern highbush blueberry cultivars for cross-pollination is recommended.

Performance

Georgia Dawn™ was established at the UGA Blueberry Research Farm in Alapaha, GA, and at a grower test site in Ware County, GA, as multiple plants in 2004. An additional grower test site was established in 2007 in Bacon County, GA.

An outstanding feature of Georgia Dawn™ is early ripening fruit (Tables 1 through 3). In all tests in southern Georgia locations, Georgia Dawn™ averaged ripening 7 to 12 d earlier than ‘Star’ or ‘Rebel’ and ripened more than 2 weeks earlier than ‘Emerald’ (USPP 12165) (Lyrene, 2008). A more detailed view of ripening time is shown in the yearly data for the cultivars being compared at the Alapaha Research Farm location over a multiyear period (Table 4). In each year, Georgia Dawn™ consistently ripened earlier than any of the other three commercial cultivars. The data are estimates of 50% ripening time, and typically berries will begin ripening (10% ripe fruit) 7 to 10 d earlier than this. Thus, with Georgia Dawn™, there was harvestable fruit ready on the plants in some years by 15 Apr., which is very early ripening for southern Georgia.

Table 1.

Five-year average ratings of some fruit and plant characteristics of Georgia Dawn™ and standard southern highbush cultivars Emerald, Rebel, and Star (2006–11) in field test plots at Alapaha, GA.^z

View Table

Table 2.

Five-year average ratings of some fruit and plant characteristics of Georgia Dawn™ and standard southern highbush cultivars Emerald, Rebel, and Star (2005–10) in field test plots at a grower test site in Ware County, GA.^z

View Table

Table 3.

Three-year average ratings of some fruit and plant characteristics of Georgia Dawn™ and standard southern highbush standard cultivars Emerald, Rebel, and Star (2009–11) in field test plots at a grower test site in Bacon County, GA.^z

View Table

Table 4.

Date of 50% ripening for Georgia Dawn™ and three standard southern highbush blueberry cultivars at the Alapaha Research Farm during 2006–11.^z

View Table

As mentioned previously, the early-ripening berries of Georgia Dawn™ are coupled with an early flowering time as well. Data from the three trials indicated that the fruit development period of Georgia Dawn™, ‘Rebel’, and ‘Star’ is similar and that Georgia Dawn™ simply starts flowering earlier. This early flowering can result in freeze/frost issues during many years in southern Georgia; therefore, it is recommended that Georgia Dawn™ be grown using freeze protection measures (i.e., overhead sprinkler frost protection) when possible. Early flowering has often caused problems with growers producing the variety ‘Emerald’. Growers particularly become frustrated with the fact that although ‘Emerald’ flowers early, it does not ripen early; thus, there is little reward for the risk of growing the cultivar. However, the early ripening of Georgia Dawn™ should offer growers a chance for higher market prices, thus a reward for the risk.

Along with very early-ripening fruit, Georgia Dawn™ has additional favorable attributes. In most evaluations, Georgia Dawn™ had the best flavor as compared with the other cultivars, especially to ‘Rebel’ (Table 5). ‘Rebel’ often has bland flavor, and Georgia Dawn™ offers an improvement. Georgia Dawn™ fruit size is similar to ‘Star’ in most years, although ‘Rebel’ berry size was larger. Georgia Dawn™ has a good fruit scar and good plant vigor. Firmness is less than ‘Star’ and ‘Rebel’ but is adequate.

Table 5.

Berry weight, firmness, and Brix for Georgia Dawn™ and standard southern highbush blueberry cultivars grown in Griffin, GA, during 2013.^z

View Table

Although yields were not obtained in the trials, cropping estimates (related to yield) were made each year for the various trial entries. Georgia Dawn™ cropping has been good, especially for an early-flowering cultivar. Note that plants at the Alapaha site were not frost-protected in any year, whereas the Ware County site was frost-protected in some years, and the Bacon County site was frost-protected each year. Georgia Dawn™ has demonstrated good flower bud production and fruit set, both contributing to reasonable yield potential.

Availability

Southern highbush blueberry ‘TH-819’ (USPPAF) Georgia Dawn™ is owned by the University of Georgia Research Foundation. Propagation rights controlled by the University of Georgia Research Foundation, Technology Commercialization Office, GSRC Boyd Building, Athens, GA 30602-7411 (<http://www.ovpr.uga.edu/tco/>).