Table 1. The combinations of spacing and target graft height in the studied treatments within the experimental seed orchard.
  Target height of grafts (m)  
Stems ha–1 Spacing (m) 2 3 4 5 6 Plot size (m) No. grafts in
each central plot
4000 2.5 × 1.0 A         15 × 15 52
2000 5.0 × 1.0 C         15 × 15 16
1600 2.5 × 2.5 B         15 × 15 13
1333 5.0 × 1.5 D         15 × 15 8
889 7.5 × 1.5 F         15 × 30 16
800 5.0 × 2.5   E       15 × 30 16
667 7.5 × 2.0   G H     15 × 30 10
533 7.5 × 2.5   I   K L 15 × 30 8
267 7.5 × 5.0     M N O 30 × 30 8
1

Fig. 1. Graft height before pruning in the autumn each year for treatments with different target heights.

Table 2. Percentage of pollen-producing grafts (seed orchard age 9–11) and pollen production per year (seed orchard age 12–20) in the different treatments. View in new window/tab.
2a
2b

Fig. 2. Cone size, measured as number of cones per litre, from seed orchard age 6 to 21. In A: treatment A–H. In B: treatment I–O. Average for all treatments in both A and B.

Table 3. Cone production (hl ha–1) for the combinations of spacing and target graft height in the experimental seed orchard. First figure is cone production from age 6 to 13 and second figure is cone production for the whole studied period (age 6 to 21).
  Target height of grafts (m)
Stems ha–1 Spacing (m) 2 3 4 5 6
4000 2.5 × 1.0 105 / 177        
2000 5.0 × 1.0 73 / 183        
1600 2.5 × 2.5 90 / 193        
1333 5.0 × 1.5 60 / 144        
889 7.5 × 1.5 41 / 132        
800 5.0 × 2.5   55 / 223      
667 7.5 × 2.0   44 / 168 64 / 230    
533 7.5 × 2.5   41 / 159   31 / 238 51 / 237
267 7.5 × 5.0     37 / 181 38 / 232 46 / 252
Table 4. Seed mass (g (1000 seeds)–1) for the seed production from seed orchard age 6 to 21 for the different treatments. View in new window/tab.
Table 5. Seed production (kg ha–1) for the combinations of spacing and target graft height in the experimental seed orchard. First figure is seed production from age 6 to 13 and second figure is seed production for the whole studied period (age 6 to 21).
  Target height of grafts (m)
Stems ha–1 Spacing (m) 2 3 4 5 6
4000 2.5 × 1.0 67 / 115        
2000 5.0 × 1.0 44 / 109        
1600 2.5 × 2.5 55 / 122        
1333 5.0 × 1.5 41 / 97        
889 7.5 × 1.5 28 / 88        
800 5.0 × 2.5   39 / 148      
667 7.5 × 2.0   30 / 111 44 / 153    
533 7.5 × 2.5   27 / 98   22 / 158 37 / 158
267 7.5 × 5.0     27 / 116 22 / 128 29 / 172
3a
3b

Fig. 3a. Cumulative seed production per hectare from seed orchard age 6 to 21 (kg ha–1) in treatments with A: target height of 2 metres, and B: target height of 3 metres.

3c
3d

Fig. 3b. Cumulative seed production per hectare from seed orchard age 6 to 21 (kg ha–1) in treatments with C: target heights of 4 and 5 metres, and D: target height of 6 metres.