ACID-SOIL-STRESS INFLUENCE ON MINERAL-ION CONTENTS OF SORGHUM LEAVES AND JUVENILE PANICLES

Sorghum [Sorghum bicolor (L.) Moench cv RTX430, SC214, SC574, SC599, TAM428, and SC326xSC103] were grown on soils of pH 4.2 or 6.2-6.5. Leaf and nonexserted juvenile panicle tissues were collected at 75 days after planting. Fresh and dry weights were measured and element contents [sulfur (S), phosphorus (Pi, magnesium (Mg), calcium (Ca), potassium (K), zinc (Zn), iron (Fe), and copper (Cu)] were measured by atomic absorption. Significant cultivar differences in ion concentration (mu mol/g dry weight) were found. Juvenile panicles had higher ion concentration (mu mol/g dry weight) [S, P, Mg, Ca, K, Zn, and Cu) than leaves. Within leaf tissue, ion concentration (mu mol/g dry weight) was correlated with tissue water content (g water/g dry weight).