2019 ASHS Annual Conference

Three main commercial types are grown for the United States blueberry market. These are northern highbush (NHB, Vaccinium corymbosum L.), rabbiteye (RE, V. virgatum Aiton), and southern highbush (SHB, Vaccinium sp., which is a species complex between V. corymbosum L. and V. darowwi Camp). NHB blueberry types are grown in northern states of the country. The majority of blueberries grown in Georgia are RE and SHB types. SHB and NHB blueberries are perceived to have superior fruit quality characteristics compared to RE, yet information to support this is limited. Storage capability, rate of spoilage, and fresh postharvest keeping quality of these types is largely unknown. The main objective of this study was to investigate if percent healthy fruit of respective cultivars can be predicted based on 2017 and 2018 blueberry harvest seasons’ physical and chemical fruit quality attributes of SHB, RE, and NHB blueberries. Fruit were collected from commercial packers representing the early-, mid-, and late- 2018 harvest season from Michigan, Canada, and Georgia. Cultivars included were: seven SHB [‘Star’, ‘Farthing’, ‘Meadowlark’, ‘Legacy’(from GA and MI), ‘Camellia’, ‘Keecrisp’, and 'Suziblue’], five RE (‘Vernon’, ‘Alapaha’, ‘Brightwell’, ‘Powderblue’, and ‘Austin’), and five NHB (‘Bluecrop’, ‘Draper’, ‘Nelson’, ‘Elliott’, and ‘Liberty’). All except ‘Powderblue’, ‘Austin’, and ‘Brightwell’, were hand-harvested. Fruit were kept at 4 °C after collection and processed for a 30 day period at four timepoints (TP): 1) 3-4 days, 2) 10-11 days, 3) 20-21 days, and 4) 30-31 days. Physical characteristics evaluated included: skin strength (puncture-in), and fruit firmness (Kramer shear). Chemical characteristics evaluated include: soluble solids, total titratable acidity, and sugar/acid ratio. Low and high ethylene emitting cultivars were also evaluated to see their relationship with percent healthy fruit. Pearson’s correlation coefficients were performed between physical and chemical fruit attributes during TP1 and % healthy fruit of TP3. Analyses will determine significant differences in % healthy fruit and significant correlations that will enable early detection of postharvest losses that certain cultivars may experience more than others. Indicators of percent healthy fruit would be beneficial to producers to target specific markets based on postharvest storage capabilities of cultivars and choose those cultivars best suited for long term postharvest storage. This information will be used to help growers and breeders select and develop new cultivars with superior postharvest keeping quality.