Tree Improvement Program Project Report 2006 / 2007

crown. If crown pruning helps to re-invigorate the lower
crown, then we may expect lower-crown cones to increase
relative to the control block.
Seed y elds
Figures 44 and 45 show the mean total seed per cone
(TSPC) and filled seed per cone (FSPC) for the three
top-pruned blocks. TSPC and FSPC both declined in the
year following pruning (2005) and increased slightly in
2006. Although we would not expect pruning treatments
to produce substantial differences in cone yields, there is a
small, positive indication that yields in the moderate and
severe pruning blocks were higher in 2006. This result may
indicate that re-invigorating the crowns by top-pruning
improved seed set. We will closely follow this result in the
next few years.
Figures 46 and 47 show the FSPC data from the three
top-pruned blocks by lateral-pruning (Figure 46) and by
Seed Cone Number
Total seed per Cone
Filled Seed per Cone
10
8
6
4
2
0
60
50
40
30
20
10
0
50
40
30
20
10
0
T R E E I M P R O V E M E N T P R O G R A M
2004 2005 2006
2004 2005 2006
2004 2005 2006
P R O J E C T R E P O R T 2 0 0 6 / 2 0 0 7
crown height (Figure 47). Again, FSPC values were slightly
better in the top-pruned blocks, but they were unaffected
by lateral pruning. It is too early to determine if this is a
trend or just a yearly variation. Again, subsequent years’
observations will determine if this is a trend.
Figure 47 shows the difference in seed yields by crown
position. Yields were higher for upper-crown cones, but the
magnitude of the difference was smaller for the moderate
and severely pruned bocks. Again, this may indicate that
lower crowns of top-pruned blocks are more vigorous.
Finally, Figure 48 shows the differences in seed cone
yields by insect protection for each of the three topping
blocks. Although seed loss to insect predation is not
necessarily associated with top-pruning treatments, this
data clearly shows that seed losses in 2006 were in the order
of 10 FSPC. In the two Kalamalka lodgepole pine seed
orchards, insect damage in 2006 was among the highest
ever recorded.
Con
Mod
Sev
Con High
Con Low
Mod High
Mod Low
Sev High
Sev Low
F gure 3. Mean seedcone
counts for a
major whorl branch n
the upper and lower
crown.
F gure . Mean total seed per cone (TSPC).
Con
Mod F gure . F lled seed per cone (FSPC)
Sev for the three top-pruned blocks.