Seemen, H. and Jäärats, A. 2005. The Quality of Pine and Spruce Planting Stock in Estonia. Baltic Forestry, 11 (1): 54-63

The present research is a comparative analysis of how the main quality indices of cell-grown and bare-rooted planting stock - plant height, root collar diameter and their ratio, above-ground biomass, below-ground biomass and their ratio - conform to the existing planting stock standard in Estonia. Data were collected from the nurseries in different state forest regions in the period 2001-2003. Pine and spruce cell-grown plants were grown in Ecopot containers with the density of 400 plants per m2, bare-rooted pine seedlings and spruce transplants were grown using traditional field-grown technology. The mean height of the same species container-grown and bare-rooted plants differed relatively little (7-14%). The root collar diameter of pine container-grown stock formed 69% and the corresponding index of spruce container-grown stock 51% from the root collar diameter of the same species bare-rooted plants. The above-ground mass of container-grown spruce stock was on average 4.7 times smaller than the corresponding number of bare-rooted transplants, the relative difference between above-ground mass of pine container-grown stock and bare-rooted seedlings was smaller (2 times). Beside measurements the proportional development of different plant parts is essential as well. It turned out that the root mass of the 2-year-old bare-rooted pine seedlings was relatively small compared with above-ground biomass (above-ground and below-ground dry mass ratio was 4.9-6.4), which may decrease plant establishment in cultivating. Spruce container-grown stock had too high height and root collar diameter ratio (6.6-8.3), which make plants in cultivation less resistant to physical damage factors.

Key words: Scots pine, Norway spruce, bare-rooted plants, cell-grown plants, quality of plants.