Influence of rootstock on fruit entity, quality and antioxidant properties of fresh apricots (cv. ‘Pisana’)

Figures & data

Figure 1 Daily maximum and minimum temperatures recorded from November 2009 to March 2011. Arrows indicate the threshold of 1000 CU accumulated.

Table 1 Monthly mean maximum and minimum temperatures (°C), relative average (Avg) and cumulative rainfall (mm) from April to June over two growing seasons (2010–11).

	2010				2011
	T max	T min	Avg	Rainfall	T max	T min	Avg	Rainfall
April	23.5	8.7	16.7	58	24.0	8.9	16.4	23.3
May	24.2	12.5	18.7	105	26.7	11.8	19.2	11.7
June	26.7	13.5	20.1	30	28.0	14.4	21.2	11.7
Total May–June				135				23.4
Total				193				46.7

Figure 2 Flowering period (JD = Julian days) and harvest time recorded over two growing seasons (2010–11) in ‘Pisana’ cultivar grafted on to apricot ‘Seedling’ and ‘Myrabolan 29/C’. Harvest = days after harvest date of the reference cultivar ‘San Castrese’ (1 July in central Italy).

Figure 3 ‘Pisana’ apricot cultivar grafted on to two rootstocks (‘Myrabolan 29/C’ and apricot ‘Seedling’). Percentage of flowering and fruiting recorded over two growing seasons (2010–11).

Table 2 Main physical-chemical traits in apricot fruits of ‘Pisana’ cultivar grafted on to ‘Myrabolan 29/C’ and apricot ‘Seedling’ recorded at ready-to-eat stage and after 14 days of 4 °C cold storage. Mean of a 2-year period ± SEM.

Rootstock	SC-b (classes)	SC-ub (classes)	Fruit weight (g)	Firmness (kg 0.5 cm^−2)	TSS (°Brix)	TA (meq 100 g^−1 FW)	TSS/TA
Ready-to eat
Myrabolan 29/C	2.0 ± 0.1	7.1 ± 0.2	73.3 ± 3.5*	2.3 ± 0.4	13.6 ± 0.4	14.4 ± 0.9	0.94
Seedling	3.1 ± 0.2	7.3 ± 0.1	52.6 ± 1.9	2.2 ± 0.1	13.2 ± 0.7	11.7 ± 0.2	1.12
Rootstock effect^a			P < 0.0001	NS	NS	P = 0.0097
Year effect^a			NS	P < 0.0001	P < 0.0001	NS
R × Y interaction^a			NS	NS	P = 0.0002	NS
After cold storage
Myrabolan 29/C	2.3 ± 0.1	8.1 ± 0.2	63.3 ± 3.2*	1.6 ± 0.1	14.0 ± 0.4	14.8 ± 0.7	0.94
Seedling	3.0 ± 0.2	7.1 ± 0.2	48.4 ± 2.4	1.7 ± 0.1	13.4 ± 0.6	11.2 ± 0.2	1.19
Rootstock effect^a			P < 0.0001	NS	NS	P = 0.0137
Year effect^a			P = 0.0238	P < 0.0001	P < 0.0001	NS
R × Y interaction^a			P = 0.0365	P = 0.0346	P = 0.0346	NS

* Significant differences between ‘Myrabolan 29/C’ and ‘Seedling’ rootstocks were tested by t-test, P ≤ 0.05.

^a Two-way ANOVA.

SC-b, skin colour of the blushed side; SC-ub, skin colour of the unblushed side; TSS, total soluble sugars; TA, titratable acidity; R, rootstock; Y, year; NS, not significant.

Figure 4 ‘Pisana’ cultivar grafted on to ‘Myrabolan 29/C’ and apricot ‘Seedling’: apricots at ready-to-eat stage and after 14 days of 4 °C cold storage. A, Total antioxidant capacity. B, Total phenols over two growing seasons (2010–11). Means ± SEM. Means with different letters are significantly different (P ≤ 0.01) according to Tukey's test.

Table 3 Two-way ANOVA results at ready-to-eat. Variables: TAC (µmol TE g⁻¹ FW) and TP (mg GAE g⁻¹ FW).

	TAC	TP
Main effects	P	P
Year	< 0.0001***	0.0004***
Rootstock	0.0102*	0.0293*
Interaction
Year × Rootstock	0.2789^NS	0.04*

NS, not significant.

*, *** significant at P < 0.05 and 0.001, respectively.