Seasonal Partitioning of Dry Matter and Nitrogen in Andropogon Tectorum Regenerated from Rhizomes
Seasonal partitioning of dry matter and nitrogen over a growing season in Andropogon tectorum regenerated from rhizomes were studied under nutrient and water regimes in sand culture. The dry matter and nitrogen content of Andropogon tectorum was partitioned into leaf, stem, root and rhizoms fractions under both regimes. The leaves constituted the largest component of the biomass under both treatments over the growth period and its contribution ranged from 30.96% to 72.19% while the rhizome constituted more or less the least component of the biomass (3.19% to 38.25%) over the entire growth period except at the early stage and stem and root had intermediate proportions. Percentage total nitrogen in leaf, stem, root and rhizome generally declines from the beginning of growth period to maturity. The total nitrogen concentration of leaves of both treatments was constantly higher than those of other parts monthly throughout the study period. The proportion constituted by the leaves declined from the early stage to maturity whereas in rhizomes the proportion was increasing from the early stage to maturity. At maturity a notable general trend of percentage total nitrogen proportions constituted by different parts of plants is that proportion constituted by belowground parts was higher than those of above-ground parts while reverse was the case with dry matter.