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Norway spruce seedlings were grown with three, peat based growth media (Table 1) subjected to three irrigation regimes in three forest nurseries in the Eastern part of Norway. The irrigation regimes were defined by the volume of liquid in the growth growth substrate one hour after irrigation and re-irrigation started when 20, 40 or 60 % of this volume of liquid was lost. The irrigation frequency and intensity was determined by the weight of specific multipot containers (Fig. 1). The results differed from what we expected from literature and laboratory studies: The deviations were mainly attributed to variation within the `experimental treatments`. Great variation was observed in bulk density, ash concentration and phase distribution in the growth media (Table 1, Figs. 2 and 3), and within, although not always between, irrigation regimes (Figs. 4, 5, 6 and 7). The experiment was further disturbed by the influence of growth media on germination (Table 2). The dry weight of seedlings did not relate to irrigation and growth media in an unique manner (Fig. 8): The variation in important factors and the improper control of the irrigation regimes made a discussion with respect to `average` growing conditions impossible. The results initiated a discussion on research strategies in the `applied sciences`, and the conclusion was towards more distinct criteria for the `applied` and the `science`. The variation and the unreliable routines induced this question: Which of the individual seedlings were under which of the irrigation regimes in which growth substrate and under which climate at which time and at which of the nurseries?. In conclusion, the variations in growth media properties, germination and growing routines have to be delt with in a better way than at present before a satisfactory growing control is achieved.


Frost damages may take place by rapid intracellular freezing or by extracellular ice formation and cell dehydration. The damages are measured visually or by electroconductivity measurements.The first hardeing stage is induced by short days and light, and is related to dormancy induction. The second stage is induced by low temperatures (-2-5 C). During this and the third stage, water binding forms of proteins and sugars are formed, and the membranes are re-structured in order to better withstand dehydration.Potassium prevents frost damages by increasing the resistance against dehydration while nitrogen and phosphorus in high concentrations are extending the growth period and exhaust carbohydrate reserves, making the plants more exposed to frost damages.


In the spring 1955 an experimental plot with 6 provenances of Scots pine from Norway was laid out in a fjord district at 69°04\"N - 60 m a.s.l.: Prov. 1. Målselv - 69°N, 0-150 m a.s.l. Prov. 2. Grovfjord - 68°40\"N, 0-150 m a.s.l. Prov. 3. Skjomen - 68°15\"N, 0-150 m a.s.l. Prov. 4. Saltdal - 66°55\"N, 0-150 m a.s.l. Prov. 5. Halsa - 63°05\"N, 0-150 m a.s.l. Prov. 6. Rindal - 63°05\"N, 0-150 m a.s.l. The plot was laid out on a clear-cut in a birch forest. In the surrounding area, the pine occurs spontaneously only as scattered single trees. The plot (90 m x 90 m) was divided in 36 squares (15 m x 15 m), and each provenance repeated 6 times. The spacing of plants was 1,5 m x 1,5 m. Each provenance was represented by 600 plants. Prov. 3 has been transferred about 100 km (aerial line) from south to north, Prov. 4 about 240 km. Fig. 1 shows the reduction in the survival percentage in the years 1955 to 1985. At the total age of 34 years, a strong correlation has been found between the survival percentage and the northern latitude of the provenances. In Fig. 8 is shown that the total production is related to the number of plants per hectare. The number of plants per hectare is decreasing with decreasing latitude of the provenances (Table 6). Provenances transferred 100 km or more from south to the north are not to be recommended by plantations in the fjord districts in Troms. They probably give less total production, larger diameters of stems and branches (Table 5), and lower values in the relationship of H/D (Height in m/Diameter in cm) than the most northern provenance (Table 6). The main reason is the lower density of plants caused by lower survival percentages by the southern provenances. However, the trees of the two most southern provenances (Prov. 5 and 6) have also revealed considerably less height growth than the others (Table 3). Prov. 1 and 2 originate respectively from inland and fjord districts. The results from the actual experiment show that the provenance from the inland of Troms has to be preferred by planting of Scots pine in the actual fjord district. In 1956 another experiment was laid out in the same area. This experiment included also comparison between Prov. 1 and 2 (Bergan 1987). The results at the total age of 27 years confirm the conclusions about these two provenances in this report.