The 2011 ASHS Annual Conference

The effects of adjusting soil pH with diluted sulfuric acid (H₂SO₄) solution were investigated to maintain stable and vigorous growth without root damage in blueberry. The ‘Spartan’ blueberry which was planted in 45L black unwoven container was used to fine out the proper concentration of sulfuric acid. To adjust soil pH level to 4.5 from 6.3 untreatment, 3 concentrations of sulfuric acid of 10^-2N, 10^-3N and 10^-4N were injected with 15L per container once a week. The targeting soil pH 4.5 can be reached faster when injected with the higher concentration of sulfuric acid solutions. However, the concentrations of cation contents including potassium and calcium were slightly lower as 0.12, 0.38 cmol⁺ kg^-1 in 10^-2N sulfuric acid treatment than the other treatments. The treatment of 10^-4N sulfuric acid solution showed highest leaf size and fruit weight as 2.0 cm2 and 2.4 g but presented lowest total acidity as 0.45% among treatments. In the treatment of 10^-3N sulfuric acid solution, soluble solid content was highest as 16.2 °Brix and shoot length and width were also highest as 59.1 cm and 6.16 mm. In conclusion, tree growth and fruit marketability were better in the treatment of 10^-3N sulfuric acid solution than the others though leaf size was the biggest in 10^-4N sulfuric acid treatment. The sulfuric acid solution of 10^-3N would be a suitable treatment for tree growth and fruit quality through the adjusting soil pH to 4.5 without root damage in ‘Spartan’ blueberry.