1976 Volume 45 Issue 3 Pages 217-224
1. The physiological characteristics of satsuma mandarin trees having flowers with or without leaves make an interesting object for study.
2. Six 15-year-old satsuma mandarin trees growing at Fujieda in the citrus region of Shizuoka, were selected for their uniformity in size and other general conditions.
3. It might be assumed that the production of flowers is a reaction to the supply of elaborated food material in the tree and that the tree responds by putting forth leafy and/or leafless flowers, corresponding to the vigour of vegetative growth.
4. The figures given in Table 1 show the percentage distribution of fruit branches according to length, diameter at the base and volume.
A survey of this Table shows longer and larger branches present on oblique and vertical framework branches.
There is evidently a tendency for the vertical framework branches to produce stronger fruit branches.
5. The figures given in Table 2 show flower production on fruit branches of different lengths for vertical, oblique and horizontal framework branches.
In order to place the number of flowers produced on the fruit branches of different lengths on a comparable basis, the results are expressed per 10cm length or per 1cm3 volume of each fruit branch.
Many more flowers are produced on short fruit branches growing from horizontal framework branches.
There is evidently a tendency for fruit branches of poor growth to produce far more flowers per 10cm length and per 1cm3 volume.
6. The figures given in Table 3 show that both leafy and leafless flowers are produced most profusely on short fruit branches present on the horizontal framework branches, and this is particularly true of leafless flowers.
7. The figures given in Table 4 show that the leafless type is produced more abundantly on fruit branches present on the horizontal framework branches and less on fruit branches present on the vertical framework branches.
The leafy type is produced more abundantly on fruit branches present on the vertical framework branches, the opposite of the situation for the leafless type.
8. It is shown in Table 6 and Fig. 6 that the development of the leafless flowers is inferior to that of the leafy flowers in size and weight. The leafless flowers, present on fruit branches of poor growth, are inferior in the nutritional competition and tend to cease growth and abscise earlier in the season.