Variation in Chemical Composition of Dracaena sanderiana Leaves as Influenced by Leaf Maturity and Shade Intensity

Abstract

Seventy-five tops of D. sanderiana were grown and harvested, 15 from each of five different shade intensities. The leaf blades of each top were separated as to position in the stem. Composite samples of the leaves having the same numbered position in the 15 tops at each level of shade were chemically analyzed for nitrogen, phosphorus, potassium, calcium, and magnesium. Leaf position definitely influenced the chemical content of the leaves. The immature leaves showed lower values of nitrogen, calcium and phosphorus. The values increased with age. There was a reduction in the chemical content farther down in the stem. Leaf potassium was high in the young leaves with a definite decrease with age, until it became stabilized or it increased in the old leaves. Leaf phosphorus did not seem to vary with age. The shade intensities did not seem to affect the leaf nutrient content markedly, except potassium and magnesium to some extent, expecially in immature leaves. Functional relationships were established for leaf position and leaf nutrient content, with a high percentage of explanation of the variability. It can be concluded that leaf samples midway in the stem are suitable for analysis. Leaves of the 2d, 3d or 4th position will possibly reflect the nutritional status of the plant.