Size of Necrotic Areas on Poplar Bark (Caused by the Fungus Dothichiza populea Sacc. et Br.) and their Dependence on Plant Development

1989

4 Tab., 20 Lit. Ang.

Unselbständiges Werk

6366

200055910

Investigations of dependence of the size of necroses on the rooting ability of artificially inoculated cuttings and development of shoots from cuttings in a certain period of time were carried out within a large-scale study on pathogen characteristics of Dothichiza populea Sacc. et Br. in different clones (Avramovic, 1988). In all examined clones a relation between the size of necroses and development of plant can be observed, as well as, between degree of the roting ability and length of formed shoot. In order to examine this connection two field experiments were established. Eight cuttings of four clones (cl. I-214, I-45/51, 618 and 725) were inoculated artificially by mycelium. In the first trial there were four repetitions, and in the second one three (one repetition 8x4=32 cuttings). Cuttings with the length 35 cm were picked at a distance 10x10 cm, with inoculum above the ground, so that it can be developed freely in cortical tissue. In the first trial cuttings were grown 110 days, and in the second one 165, after what they were taken out and evaluated. On the basis of the obtained results and analyses it can be concluded that on cuttings of four poplar clones, artificially inoculated by mycelium of the fungus Dothichiza populea grown in the field under the same conditions, different size of necroses were obtained. On cuttings with good rooting ability considerably smaller size of necroses were observed than on cuttings without roots (Table 1 and 2). On plants with more developed shoots considerably shorter necroses are formed when compared to plants with not so developed shoots (Table 3 and 4). Damages caused by D. populea in poplar plantations can be considerably reduced by introducing measures for improving development of the root system and development of crown.