Apple rootstock tables

A quick rootstock reference guide for South African growers that includes the results of local evaluation trials.

Notes

1. Varieties marked with an asterisk (G.757, G.41, G.213, G.214, G.969, G.210 and G.890) are not on the official South African varietal list and are included for informational purposes only. Listing in these tables does not constitute an offer for sale by any variety owner.
2. Empty table cells indicate that no data is available.

 

Table 1: Parentage and plant attributes

Rootstock	Parentage	Vigour as % of seedling	Branching compared to M-range1	Graft strength
M.9 T337	M.9 (Naktuinbouw)	30–40	–	Weak
M.9 EMLA	M.9 (East Malling & Long Ashton)	40	–	Weak
M.9 Nic29	M.9 (Boomkwekerij René Nicolaï)	40	–	Weak
G.757*	Robusta 5 x Ottawa 3	40	High	To be determined
G.41*	M.27 x Robusta 5	40	–	Weak
G.213*	Robusta 5 x Ottawa 3	40	High/Medium	Weak
G.214*	Robusta 5 x Ottawa 3	40	–	Strong
G.202	M.27 x Robusta 5	40–50	High/Medium	Strong
G.222	M.27 x Robusta 5	50–60	High/Medium	Medium4
M.7 EMLA	M.7 (East Malling & Long Ashton)	60	–	Strong
G.969*	Robusta 5 x Ottawa 3	60 (30)2	High	Weak/Strong4
G.210*	Robusta 5 x Ottawa 3	60	High	Strong
G.890*	Robusta 5 x Ottawa 3	60	High	Strong
M.793	M.2 x Northern Spy	70	–	Strong
G.228	M.27 x Robusta 5	70 (60)3	Medium	Strong
MM.109	M.2 x Northern Spy	80	–	Strong
G.778	M.27 x Robusta 5	80–90 (70)3	Medium	Strong

¹ Based on results on extent of branching relative to M-range rootstocks obtained in Brazil. This may reflect the rootstock effect on correlative inhibition rather than chill requirement.

² G.969 vigour in industry trials has been < 30% of seedling due to either the presence of latent viruses in scion material or stunting in low pH soil.

³ G.228 and G.778 displayed slightly reduced vigour of 60% and 70% respectively compared to seedling in an industry trial with Fuji.

⁴ Strong graft unions according to Cornell-Geneva but graft failures have been observed locally. This might relate to the virus status of scion material.

Table 2: Cumulative yield efficiency as kg fruit per cm² trunk cross-sectional area

Rootstock	Bigbucks1 4+5th leaf	Fuji1 7th leaf	Rosy Glow 7th leaf	Golden Delicious 10th leaf	Summary2
M.9 T337	1.8	–	–	–	High
M.9 EMLA	2.0 (1.8–2.1)	3.7 (3.5–3.8)	–	–	High
M.9 Nic29	1.6	3.3 (3.0–3.9)	4.4	–	High
G.757*	3.6 (2.7–4.0)	–	–	–	Very high
G.41*	3.0 (2.7–3.2)	–	–	–	High
G.213*	–	–	–	–	High3
G.214*	–	–	–	–	High3
G.202	1.9 (1.7–2.1)	3.6 (3.1–4.2)	–	–	High
G.222	2.2 (1.9–2.3)	3.2 (2.8–3.7)	3.2	5.6	High/Intermediate
M.7 EMLA	1.8 (1.7–1.9)	2.4 (1.9–3.3)	3.0	4.0	Intermediate
G.969*	2.0 (1.9–2.1)	–	–	–	High3
G.210*	–	–	–	–	High3
G.890*	2.2	–	–	–	High
M.793	0.6	1.6 (1.3–2.1)	2.7	3.6	Low
G.228	2.0 (1.7–2.2)	2.6 (2.5–2.7)	3.5	5.0	Intermediate/High
MM.109	0.7	1.5 (1.3–1.8)	2.4	–	Low
G.778	1.8 (1.6–2.0)	2.4 (2.4–2.5)	4.0	5.2	Intermediate/High

Cumulative yield efficiency is the best indicator of productivity over the duration of local industry trials. Figures are provided for individual scion cultivars since there seems to be interaction between rootstocks and scions in terms of productivity.

¹ Bigbucks and Fuji are being evaluated in multiple trials and performance differs between sites. Therefore, the table lists the average for all sites followed by the range of values (in parenthesis).

² Summary takes local and international trial data into account.

³ No local data yet. Based on international trial data.

Table 3: Susceptibility to pests and diseases

Rootstock	Crown gall	Phytophthora	Replant disease	Woolly apple aphid
M.9 T337	Moderate	Moderate	Highly susceptible	Susceptible
M.9 EMLA	Moderate	Moderate	Highly susceptible	Susceptible
M.9 Nic29	Moderate	Moderate	Highly susceptible	Susceptible
G.757*	–	–	–	To be determined
G.41*	–	–	–	Resistant
G.213*	–	–	–	Resistant
G.214*	–	–	–	Resistant
G.202	–	–	–	Resistant
G.222	–	–	–	Resistant
M.7 EMLA	Moderate	Moderate	Susceptible	Susceptible
G.969*1	–	–	–	Resistant
G.210*	Susceptible?	–	–	Resistant
G.890*	–	–	–	Resistant
M.793	–	Moderate	Susceptible	Moderate
G.228	–	–	–	Resistant
MM.109	Moderate	Moderate	Susceptible	Moderate
G.778	Susceptible?	–	–	Resistant

The information on crown gall, Phytophthora, and replant disease is based on local observations because international studies have yielded conflicting results on the susceptibility of Geneva rootstocks to Phytophthora and replant disease.

Little information is available on crown gall susceptibility.

The woolly apple aphid information is based on local observations and Cornell Geneva data.

¹ Graft union failure and severe stunting observed in local plantings might indicate sensitivity to latent viruses present in the scion material.

Table 4: Susceptibility and tolerance to lesion nematodes (Pratylenchus species)

Rootstock	Susceptibility1			Tolerance2
	Pratylenchus hippeastri	Pratylenchus penetrans	Pratylenchus vulnus
M.9 T337	Moderate	Moderate	Moderate	Tolerant
M.9 EMLA	High. Not tested in pots.	–	–	–
M.9 Nic29	High. Not tested in pots.	–	–	–
G.213*	Moderate	High	Moderate	Tolerant
G.202	Moderate	High	Moderate	Tolerant
G.222	Moderate	High	High	Some tolerance
M.7	High	High	High	Some tolerance
G.969*	Moderate	High	High	Some tolerance
G.210*	High	High	High	Tolerant
G.890*	High	High	High	–
M.793	High	High	High	Some tolerance
G.228	Moderate. Not tested in pots.	–	–	–
MM.109	High	High	High	Tolerant
G.778	High	High	High	Tolerant

Pratylenchus hippeastri makes up 85% of lesion nematodes feeding on apple in South Africa, unlike in the rest of the world where P. penetrans is the dominant species.

The data in Table 4 were generated by a study conducted by Dr Rinus Knoetze of the ARC Infruitec-Nietvoorbij. For more details, refer to the Research Rundown.

¹Susceptibility reflects nematode reproductive potential or the ratio of final to inoculated nematode numbers.

²Tolerance reflects the nematodes per gram of roots relative to the most susceptible rootstock.

A rootstock can be susceptible but show tolerance — nematodes could reproduce on it in large numbers but have little effect on growth. Conversely, a rootstock might be less susceptible to infestation but is less tolerant of the infestations and therefore more severely affected.

Table 5: Average fruit size for completed trials

Rootstock	Rosy Glow1	Fuji2
M.9 EMLA	–	148g (143g–157g) [92%]
M.9 Nic29	232g [104%]	149g (130g–160g) [93%]
G.202	–	153g (143g–166g) [95%]
G.222	235g [105%]	149 g (132g–160g) [93%]
M.7 EMLA	238g [106%]	150g (138g–170g) [93%]
M.793	233g [104%]	152g (140g–176g) [94%]
G.228	222g [99%]	163g (154g–175g) [101%]
MM.109	224g [100%]	161g (149g–182g) [100%]
G.778	228g [102%]	166g (158g–180g) [103%]

¹ The table lists the average fruit size followed by the average fruit size relative to MM.109 [% in square brackets]. MM.109 is taken as 100%.

² The table lists the average fruit size over the three Fuji sites followed by the range of values (in parenthesis). The last figure is the average fruit size relative to MM.109 [% in square brackets]. MM.109 is taken as 100%.

Note that contrary to trial results, technical advisors have generally observed bigger fruit on M.9 rootstocks compared to other dwarfing and more vigorous rootstocks.

Average fruit size is not yet available for Bigbucks trials.

Rootstocks for which no data are available have been omitted.

Table 6: Miscellaneous observations

Rootstock	Comments1
M.9 all	Does not enjoy hot and dry topsoil. Mulch.
G.757*	Very high productivity in local Bigbucks trials but additional data on more scion cultivars is needed in order to make recommendations.
G.41*	Efficient K uptake increases risk of bitter pit in susceptible cultivars. 2 Very brittle graft union.
G.213*	Found to improve lateral branching in Brazil. Development of lateral cracks in the graft union observed in Italy. This may allow pests and diseases to enter. The problem is currently being researched.
G.202	Smaller fruit size in some international trials – not yet observed in local trials.
G.222	Graft union breakages observed with some scion cultivars.
M.7 EMLA	High tendency to develop root suckers.
G.969*	Severe stunting observed locally. Might relate to soil pH or latent viruses in scion material.
G.210*	Found to increase bitter pit in some international studies.2
G.890*	Efficient K uptake increases risk of bitter pit in susceptible cultivars. 2
M.793	Vigorous rootstock more suitable for lower density or multi-leader plantings. Low productivity compared to G.288.
G.228	Vigorous rootstock more suitable for lower density or multi-leader plantings.
MM.109	Vigorous rootstock more suitable for lower density or multi-leader plantings. Low productivity compared to G.778.
G.778	Vigorous to very vigorous rootstock more suitable for lower density or multi-leader plantings on marginal sites. Not for planting under nets.

¹ The graft union and shank of M.9 and dwarfing Geneva rootstocks seem to be very sensitive to sunburn. This has a detrimental effect on growth. Painting the graft union and shank and planting under nets appears to mitigate the problem.

² Local soils are lower in K than those in some other production regions. Problems with over-accumulation of K under local conditions can be prevented by following a judicious fertiliser programme.