Effects of Hydrogen-ion Concentration of Culture Solution on the Growth of Spinachs

Abstract

Effects of hydrogen-ion concentration in the culture solution on the growth of spinachs were examined using gravel culture technique. The degree of acidity of the solution was maintained at pH 3, 4, 5, 6, 7, and 8 by adding HCl or NaOH.
Spinach growth was normal at pH 5, 6, and 7 but downward at pH 3, 4, and 8. At pH 3 and 4 leaves became darker green and at pH 8 they tended toward the occurrence of a yellowish green coloring.
Chemical analysis revealed that calcium and magnesium contents were low at pH 3 and 4, while iron, manganese, and boron contents decreased significantly as pH increased.