Rootstock Scion Interaction and Effects on Vine Vigor, Phenology, and Cold Hardiness of Interspecific Hybrid Grape Cultivars (Vitis spp.)

Figures & data

FIGURE 1 Diagrammatic representation of phenological characteristics of the two cultivars utilized in the experiment. On a relative scale, ‘Vidal’ tends to have higher vine vigor (+40%) and reduced cold hardiness (-10%) than Foch. Also, ‘Vidal’ tends to commence bud break 10–14 days later than ‘Foch’ and harvest for ‘Vidal’ is 25–30 days later than Foch in Michigan. Bud break for Foch is between the end of April and the first week of May. Harvest for Foch is between the last week of August and the first week of September (unpublished data from Michigan Lake Shore Appellation).

TABLE 1  Main Effects of 4 Years of Data Averages on Influence of Reciprocal Grafts of ‘Marechal Foch’ (F) and ‘Vidal Blanc’ (V) on Vine Growth Characteristics, Yield, Yield Components, and Basic Fruit Chemistry

	Treatment^z
	Marechal Foch scion			Vidal blanc scion			Above ground^w			Below ground^w
Treatment code	F-OR	F-F	F-V	V-OR	V-V	V-F	F	V	F^w	F	V	F^w
Vine size (kg/vine)	1.92 b	1.34 b	2.43 a	2.20 a	2.21 a	1.99 a	1.9	2.1	ns	1.7	2.4	**
Nodes retained	37 b	33 b	40 a	28 a	28 a	25 a	37.0	27.0	**	29.0	34.0	*
Shootless nodes	5.0 a	5.0 a	3.0 a	15.0 a	15.0 a	17.0 a	5.0	16.0	***	11.0	10.0	ns
Vine yield (kg/vine)	7.25 b	7.20 b	8.01 a	9.25 a	9.66 a	10.4 a	8.0	9.4	ns	8.8	9.8	**
Cluster number/vine	131 a	123 a	138 a	60 a	58 a	65 a	131.0	61.0	***	94.0	99.0	ns
Berry weight (g)	1.1 a	1.1 a	1.1 a	1.7 a	1.7 a	1.6 a	1.1	1.7	***	1.3	1.4	ns
Berries/cluster	66 a	67 a	79 a	109 a	111 a	124 a	37.0	115.0	***	96.0	93.0	ns
Cluster weight (g)	70 a	70 a	83 a	180 a	181 a	198 a	74.0	185.0	***	132.0	132.0	ns
Cluster/nodes retained	3.5 a	3.4 a	3.4 a	2.1 a	2.1 a	2.7 a	3.5	2.3	**	3.0	2.7	ns
Yield/nodes retained	229 a	241 a	261 a	389 a	427 a	501 a	238.0	348.0	***	276.0	287.0	ns
Ravax Index^x	13.5	18.6	11.2	11.5	12.0	16.0	4.3	4.6		5.3	4.0
°Brix^y	20.0 a	19.3 b	19.3 b	19.4 a	19.6 a	20.1 a	19.8	19.8	ns	21.6	19.5	*
Sugar/vine (kg)	1.45 a	1.40 a	1.55 a	1.79 a	1.89 a	2.09 a	1.7	1.9	ns	1.6	1.9	**
pH	3.47 a	3.43 a	3.33 a	3.29 a	3.26 a	3.39 a	3.4	3.3	*	3.4	3.3	*
Titratable acidity (g/L)	10.9 b	11.1 b	12.1 a	13.2 a	13.2 a	11.2 b	11.5	11.7	ns	11.2	12.1	*
^zMeans for each cultivar in a row followed by the same letters are not significantly different at P = 0.05 by the Tukey HSD test.
^yHarvest dates for ‘Marechal Foch’ were 13, 18, 11, and 1 Sept. for years 1 to 4, respectively. For ‘Vidal blanc’ 14, 17, and 9 Oct. for years 1 to 3, and 30 Sept. for year 4.
^xRavaz Index was calculated as yield per vine (kg) divided vine size (kg).
^wMain effects of 4 years data on influence of reciprocal graft of ‘Marechal Foch’ (F) and ‘Vidal blanc’ (V) when used as scion (above ground) or rootstock (below ground) on vine yield and yields components.
ns, *, **, ***Indicate not statistically different and statistical significance at 0.05, 0,01, and 0.001 levels of probability, respectively.

TABLE 2  Main Effects of 4 Years of Data on Reciprocal Grafts of ‘Marechal Foch’ (F) and ‘Vidal Blanc’ (V) on Vine Phenology and the Impact of a Spring Freeze Event in Year 2

	Treatment^z
					Above ground^y			Below ground^y
Treatment code	F-F	F-V	V-V	V-F	F	V	F^y	F	V	F^y
Date of bud burst^x	1.6a	1.4a	11.7a	12.5a	1.5	12.1	**	7.0	7.0	ns
Days from bud burst to veraison^w	91a	88a	103a	105a	90.0	104.0	**	98.0	96.0	ns
Harvest date^v	1a	1a	29a	29a	1.0	29.0	***	16.0	14.0	ns
% of primary bud mortality^u	12a	8a	2a	1a	10.0	2.0	**	6.0	5.0	ns
^zMeans for each cultivar in a row followed by the same letters are not significantly different at P = 0.05 by the Tukey HSD test.
^yMain effects of 4 years data on influence of reciprocal graft of ‘Marechal Foch’ (F) and ‘Vidal blanc’ (V) when used as scion (above ground) or rootstock (below ground) on vine yield and yields components.
^xData expressed as number of days after first shoot per vine reached the burst stage of development. ‘Marechal Foch’ was earlier and the first vine was designed as “1”.
^wData expressed as number of days from initial shoot burst (see x above), to 50% veraison as designated by 50% of color change in ‘Marechal Foch’ and perceived fruit softening in ‘Vidal blanc’.
^vHarvest dates for ‘Marechal Foch’ were 13, 18, 11, and 1 Sept. for years 1 to 4, respectively. For ‘Vidal blanc’ 14, 17, and 9 Oct. for years 1 to 3, and 30 Sept. for year 4. Data expressed as number of days after the harvest of the earlier ripening cultivar ‘Marechal Foch’.
^uSpring freeze in year 2 of the 4-year study.
ns, *, **, ***Indicate not statistically different and statistically significance at 0.05, 0,01, and 0.001 levels of probability, respectively.

TABLE 3  Using Hardy Resistant Cultivars Marechal Foch (F) and Vidal Blanc (V) to Determine the Influence of the Above Ground Primary Bud (1⁰ Bud) and Cane Tissue Cold Hardiness (T₅₀) Influenced by the Above (Scion) or Below Ground (Root) Cultivar, Whether as a Reciprocal Graft of V-F or F-V or Own Rooted (V-V, F-F) in Dormant Season after Year 1 of the Study

	Cold hardiness (T50)^z
					Above ground^y			Below ground^y
Treatment code	F-F	F-V	V-V	V-F	F	V	F^w	F	V	F^w
2 Nov.^x
1^0 Bud	−13.5	−13.0	−12.0	−13.0	−13.5	−12.0	*	−12.5	−13.0	ns
Cane	−15.0	−14.5	−13.0	−14.0	−14.0	−14.0	ns	−14.0	−14.0	ns
27 Dec.
1^0 Bud	−25.5	−23.5	−22.0	−23.0	−23.5	−21.5	*	−22.5	−23.0	ns
Cane	−31.5	−29.0	−26.0	−29.5	−32.0	−27.0	**	−29.5	−29.0	ns
21 Feb.
1^0 Bud	−25.5	−24.5	−24.0	−24.0	−25.5	−22.5	*	−23.5	−24.5	ns
Cane	−31.5	−29.0	−28.5	−29.5	−29.5	−28.5	*	−29.5	−29.0	ns
Grand mean
1^0 Bud	−21.0	−19.5	−19.5	−20.0	−21.0	−19.0	*	−19.5	−20.5	ns
Cane	−25.5	−24.0	−22.5	−24.0	−25.5	−22.5	**	−24.0	−24.5	ns
^zT50 indicates the temperature (°C) at which 50% of the buds or canes are killed.
^yMain effects of 4 years data on influence of reciprocal graft of ‘Marechal Foch’ (F) and ‘Vidal blanc’ (V) when used as scion (above ground) or rootstock (below ground) on vine yield and yields components.
^xDate of cane collection in the vineyard.
ns, *, **, ***Indicate not statistically different and statistically significance at 0.05, 0,01 and 0.001 levels of probability, respectively.