2019 ASHS Annual Conference

Southern highbush blueberry production requires acidic and well-aerated soil with high organic matter. Thus, soil amendment cost represents around one third of the total initial investment for blueberry traditional production. As a result of the high establishment cost, it takes growers more than five years to archive profits. The number of years from investment to archiving profits can be reduced by increasing earnings in the early years of production, which is increasing yield per area or advancing fruit harvest season to enter the market when price is high. This goal may be achieved by planting optimal evergreen cultivars in containers with optimal soilless substrate under high-density spacing. In this study, five evergreen cultivars and advanced selections (‘Vireo’, ‘Chickadee’, ‘FL06-19’, ‘FL09-216’, and ‘FL09-311’) with different growth habits were tested. One-year-old plants were planted in 15-gallon pots with five combinations of pine bark, coconut coir, and perlite (T1 = 5:4:1, T2= 6:3:1, T3= 7:2:1, T4= 7:3:0, and T5 = 10:0:0). Plant height and canopy size were measured in fall and after harvest. Leaf nutrient concentrations were analyzed during vegetative growth (Sept.), after last vegetative flush (Dec.), and at fruit development stage (Feb.). Yields were measured and compared among cultivars, substrates, and harvest season. After 5 months of growth, plants did not show differences in height and canopy size among substrates. The effects of substrates on berry yield were not significant as well. However, plants with substrate T5 showed greater leaf copper, manganese, and calcium concentration than those with T1 in Sept., T1 in Dec., and both T1 and T3 in Dec., respectively. Plants showed significant differences in height, canopy size, leaf nutrient concentrations and berry yield among cultivars. After nine months of planting, all cultivars except ‘Chickadee’ produced more than 1.13 kg of total yield per plant which was equivalent to 11,300 kg/ha.