EN
Seedlings produced with a covered root system were intended to be used in the afforestation of ‘difficult’ soils in post−agricultural lands, on post−fire areas, in wastelands, within zones of industrial damage or on mining heaps. It is assumed that the suitable substrate and properly grown seedling ensure a good start for a plant in a new, unfavorable environment. In many forest districts so−called ‘container nurseries’ were established and produced millions of seedlings with a covered root system, including seedlings equipped with mycorrhiza under them, controlled mycorrhization. In recent years, however, more and more often such seedlings are also introduced into forest soils during the renewal of logging or gaps. Phytopathology sees many weaknesses of such an approach. The article indicates potential and actual threats in the production cycle of planting material in containers and after planting trees in cultures.