Some aspects of the root system of tall fescue (Festuca arundinacea Schreb.)

Abstract

Some results from pot, laboratory, and field experiments studying the root system of tall fescue (Festuca arundinacea Schreb.) are presented. The root weight of vegetative tall fescue plants was found to be lower than the root weights of ryegrass (Lolium perenne L.) and cocksfoot (Dactylis glomerata L.) The variability of root weight (W_R) and of root-to-shoot ratio (R:S) in cultivars of different origins was confirmed. The average root growth rate of the tall fescue cultivars studied (RGR_R) was 0.08 g g^-1d^-1, it was reduced 50% by water deficiency. Presumably, genotypes with more robust root systems are more productive and their leaf elongation rates (LER) are higher. Both water deficiency and increased fertiliser nitrogen rates reduced the root system of tall fescue. Roots were more numerous and longer in plants produced from seeds with higher thousand-seed weight (TSW). Concentrations of N, P, Mg, and K were lower in roots than in shoots. On the other hand, concentrations of Ca, Na, Cu, Zn, and Mn were much higher in roots than in shoots. A strong negative relationship was observed between concentrations of Na in the root and shoot. The concentration of carbohydrates was lower in roots than in shoots. Among the grasses studied, the slowest root decomposition was found in tall fescue (the lowest CO₂ production), with marked differences among its cultivars. It might be concluded that root decomposition is related to the concentration of N in roots.