2017 ASHS Annual Conference

The majority of blueberry (Vaccinium corymbosum L.) production in Mississippi is using Rabbiteye blueberry cultivars, which ripen from mid-May to July. Southern highbush blueberries have the potential to provide earlier fruiting and increase growers’ competitiveness for blueberry fresh market. However, early flowering and fruiting of southern highbush cultivars are subject to late spring frost damage in Mississippi and require protection. The objective of this study is to evaluate early fruiting and yield of southern highbush blueberries grown under a high tunnel in Mississippi. One-year old liners of ten southern highbush cultivars (‘Emerald’, ‘Farthing’, ‘Georgia Dawn’, ‘Gupton’, ‘Jewel’, ‘Meadowlark’, ‘Pearl’, ‘Rebel’, ‘Star’, and ‘Sweetcrisp’) were transplanted into 15-gal plastic containers in Apr. 2015. Blueberry plants were fertilized with either a conventional slow-release fertilizer Osmocote^® Plus (15-9-12 (15N-2P-10K), 8-9 month, Scotts Miracle-Grow Co., Marysville, OH) or an organic fertilizer (5-3-4 (5N-1P-3K), McGreary Organics, Lancaster, PA). Cultivars were evaluated for the date of first ripe berry, fresh yield, single fruit weight, and soluble solid content. With the protection of a high tunnel, Southern highbush cultivars ‘Emerald’, ‘Meadowlark’ ‘Rebel’, and ‘Sweetcrisp’ produced their first ripe berry in Dec. 2015. ‘Georgia Dawn’, ‘Meadowlark’, and ‘Rebel’ produced peak harvest from Apr. 22 to May 18, 2016. ‘Emerald’, ‘Farthing’, ‘Jewel’, ‘Star’, and ‘Sweetcrisp’ produced peak harvest from May 13 to May 27, 2016. ‘Gupton’ and ‘Pearl’ are the two latest cultivars, producing peak harvest from May 27 to June 16, 2016. Peak harvest ranged from 258 g berries per plant, in organically fertilized ‘Georgia Dawn’, to 612 g berries per plant, in organically fertilized ‘Jewel’. ‘Farthing’, ‘Jewel’, ‘Meadowlark’, ‘Pearl’, ‘Rebel’, and ‘Sweetcrisp’ had comparable total fresh yield all season in 2016, averaging from 1766 g to 2136 g berries per plant. ‘Georgia Dawn’ had the lowest total fresh yield of 966 g berries per plant. ‘Sweetcrisp’ had the highest soluble solid content of 14.16 % Brix, higher than the other nine cultivars (ranging from 10.6 to 12.12 % Brix). There was no difference in total fresh yield, single fruit weight, or fruit soluble solid content between blueberry plants fertilized organically or conventionally.