| Abstract: | The chemical analysis of needles and wood of roots of trees belonging to four stages of disease caused by A. mellea in fertilized (N, P, K, Ca, Mg) and non-fertilized three Scotch Pine plantations were made. The attack caused gradual interruption of absorption and resulted in the exhaustion of some elements (N, P) and concentration of other ones (K, Ca) in needles and in the decrease of P and transitional growth of Mg-level in wood of roots. Considerable growth of concentration of some chemical substances in wood of roots of dead trees was observed. This referred to the fertilized and nonfertilized trees as well. The rate of these changes, however, was different after treatment: fertilization had no effect on the concentration of K in needles of trees in intermediate stages of disease, but it influenced in the lower rate the exhaustion of Mg in wood of roots. The role of K and Mg in defensive reactions is discussed. |
