Growing Organic Rabbiteye Blueberries in Georgia, USA: Results of Two Multi-Year Field Studies

Abstract

South Georgia is a major blueberry production region located in the warm and humid northern subtropics. The region enjoys a favorable market window, but pressure from weeds, insects, and diseases raised questions as to whether organic production would be feasible in this climatic zone. Two multi-year field studies were conducted to determine the best practices for organic culture of blueberries and to compare yields with conventional production. Various methods of weed control were tested. While organic burn-down herbicides performed poorly on the grasses that are the dominating weeds in blueberry in southern Georgia, mulches and a rolling cultivator were successful in maintaining a weed-free strip on the side of the organic beds. Hand-weeding was needed at the interface between the mulches and the cultivated strip. Pine straw and pine bark mulch resulted in the lowest hand-weeding times, whereas pine bark and wheat straw were the highest-yielding treatments. Some other locally available plant-derived or synthetic mulches also performed well for organic blueberry establishment, hence, the decision as to which mulch to use can be based partly on availability of local resources. A separate 6-year study compared yields in conventional and organic production systems. Weed problems in year 1 caused the growth of the organically managed plants to fall behind those grown conventionally, but over time very good yields (ca. 5,900 kg /ha) were produced by the organic method using pine bark mulch, and net returns over the 6-year period were higher than conventional. Organic production of rabbiteye blueberries in Georgia appears commercially feasible.