Tree Improvement Program Project Report 2006 / 2007

TSPC
FSPC
TSPC
FSPC
40
30
20
10
0
30
25
20
15
10
5
0
30
25
20
15
10
5
0
25
20
15
10
5
0
T R E E I M P R O V E M E N T P R O G R A M
Figure 1. SMP on Lower Crown Cones
Effect on Total Seed per Cone (TSPC)
high bag high no bag low bag low no bag
Figure 2. SMP on Lower Crown Cones
Effect on Filled Seed per Cone (FSPC)
high bag high no bag low bag low no bag
Figure 3. Control Cross Pollination on Lower Crown Cones
Effect on Total Seed per Cone (TSPC)
OPhi OPlow CClow
Figure 4. Control Cross Pollination on Lower Crown Cones
Effect on Filled Seed per Cone (FSPC)
OPhi OPlow CClow
moderate heat and rain. This continued through the
pollination period (Table 14), but the weather became
very hot and dry in June (Table 15), and these conditions
continued through to September (Table 16). September
had the highest heat sums and VPD sums and the lowest
rainfall recorded during the monitoring period of 2000 to
2006.
CONCLUSIONS
Increasing pollen supply, either by SMP or control cross
pollination, did not affect seed yields (TSPC and FSPC)
in lower crown cones. This suggests that pollen is not
limiting in the lower crown. It is also possible that either
pollen quality was poor or the pollination technique was
not effective. Seed yields are typically lower in the lower
crown, which may indicate a lower number of potential
P R O J E C T R E P O R T 2 0 0 6 / 2 0 0 7
F gure 33. SMP on Lower Crown Cones Effect
on Total Seed per Cone (TSPC).
F gure 3 . SMP on Lower Crown Cones Effect
on F lled Seed per Cone (FSPC).
F gure 3 . Control Cross Poll nat on on Lower
Crown Cones Effect on Total Seed per Cone
(TSPC).
F gure 36. Control Cross Poll nat on on Lower
Crown Cones Effect on F lled Seed per Cone
(FSPC).
ovules. This may be a direct result of lower crown vigour,
although crown position did not affect dry cone mass (data
not shown).
Losses to insect damage were as great as ever observed.
Weather conditions may explain the magnitude of seed
loss to insects in 2006. Tables 15 and 16 clearly show that
June and September 2006 were among the hottest and
driest months since this data has been compiled (2000).
About seven total and 10 filled seed per cone were lost in
unprotected upper crown cones, whereas in the lower crown,
less than two total and filled seed per cone were lost. These
are important observations. In orchard 307 insect damage
in the lower crown seems to be not a problem whereas in
the upper crown, it is. If we are to improve seed set in this
orchard, we must determine where losses in TSPC cones
occur, and we must reconsider insect control technique.
3