Effect of acidity on germination and seedling growth of Paulownia tomentosa.
In connection with the species' suitability for use in reclamation of acidic strip-mine environments, evaluations were made in greenhouse experiments over a pH range of 1.5-7.0. No germination occurred below pH 4.0. Seedling emergence was significantly reduced at pH 4.5. Seedling growth was depressed at pH 4.5, with significantly lower root length, leaf number and root and shoot DM, compared with seedlings grown at pH 5.5 and 6.5.