ZLV Online

The potential risk of impaired root expansion from the space of container or plug into surrounding soil exists after planting of containerized plants under extreme climatic and soil conditions of mountain localities. On research plot in the Krkonoše Mts. (Harrachov, 940 m a. s. l.) the growth of bare-rooted plants of Norway spruce (Picea abies (L.) KARST.) has been compared to containerized plants. In more concrete terms, the seedlings grown in peat pots (Jiffy pots) and seedlings (plugs) intensively grown in plastic trays in greenhouses have been tested. The development of root systems, namely growth of roots outside the planting hole, was assessed 7 years after planting. Results indicate very good root growth of seedlings grown intensively in nursery greenhouses (plugs) even under extreme conditions of mountain localities. During seven years after planting the plugs drew up the size advance of bare rooted planting stock. A different architecture of root systems among plant types was observed 7 years after planting. In all types of plants, however, a good growth of roots out of original root ball occurred, which is a prerequisite for good performance and stability of stands.