Effect of Acidity and Aluminium on the Growth of Pinus massoniana Seedlings

Effect of pH and A1 on the growth of masson pine (Pinus massoniana )seedlings was studied with liquid medium culture method. The masson pine seedlings exhibited strong tolerance toward acid conditions, growing normally at the pH range of 3.5—5.5. Growth was promoted in ultra-low concentration of Al. The masson pine seedlings were moderately sensitive to the toxicity of aluminium. The threshold of toxic concentration for aluminium to masson pine was about 4.0 ppm. Calcium ions could ameliorate the inhibition effect of A1 to some extent. The threshold ratio of A1 to Ca was about 0.2 at the level of A1 inhibition to growth of masson pine.