Post leaf-fall bud assessments

Rebecca Bruce, DPI Tatura

Buds and flowers were assessed to determine whether post harvest deficit irrigation had any effect on the following years’ fruit production. We investigated whether the irrigation treatments had an impact on flower and vegetative bud number, and if bud dry weight could be used as an indication of the trees capability to produce viable fruit. At harvest, bud number and dry weight will be compared to final yield to see whether these measurements could suggest yield potential. Bud assessment and lateral count – T204 Peaches Pruning samples were taken in late May to assess bud number and type. One lateral was removed from six positions on the two trellised trees per plot (Figure 1).

Figure 1: Position of lateral samples taken for bud assessments on T204 Peaches

The length and diameter of each lateral was measured. The number of vegetative and fruiting buds was counted (including the number of double and triple buds). Buds were removed from the wood and dried before being weighed.
The only statistically significant difference found between treatments was in the number of triple buds per lateral (Table 1). The number of triple buds was significantly greater for the two treatments receiving 160% and 200% of normal grower irrigation when compared to the treatment receiving the least amount of irrigation, which had the lowest number of triple buds. There was no significant difference in the dry weight of flower or vegetative buds.

Table 1: Flower and vegetative bud number and weight for T204 Peaches

A	Flower Bud			Vegetative Bud
Treatment	No. Doubles per Lateral	No. Triples per Lateral	Dry Weight/bud (g)	No. Per Lateral	Dry Weight/bud (g)
50%	11.6	1.0b	0.0143	23.3	0.0051
75%	10.7	3.2ab	0.0141	19.9	0.0049
100%	11.6	2.7ab	0.0139	21.5	0.0050
160%	10.7	5.0a	0.0140	18.9	0.0050
200%	9.8	4.6a	0.0152	18.8	0.0049
P*	0.500	0.018	0.369	0.182	0.992
l.s.d. (p=0.05)**	not significant	2.338	not significant	not significant	not significant

Bud assessments – WBC Pears		Table 2: Flower and vegetative bud number and weight for WBC Pears
Similarly to the peach trial, pruning samples were taken in late June from the pear trial block. One lateral was removed from the middle third of each plot tree on both the northern and southern sides of the tree. The length and diameter of each lateral was measured. The number of vegetative and fruiting buds was counted. Buds were removed from the wood and dried before being weighed. After processing, it was concluded that there was no significant difference between treatments for flower or vegetative dry bud weight (Table 2). * A ‘P’ value less than 0.05 indicates that significant differences exist between at least two of the treatments. ** l.s.d (least-significant difference) indicates which treatments are significantly different to one another. If the difference between the two treatments is greater than the l.s.d. value, they are significantly different from each other.		Treatment Flower Bud Vegetative Bud Dry Weight/bud (g) Dry Weight/bud (g) 0% 0.0367 0.0027 50% 0.0280 0.0026 100% 0.0260 0.0029 160% 0.0311 0.0031 200% 0.2770 0.0023 P* 0.797 0.396 l.s.d. (p=0.05)** not significant not significant