Apple Rootstock

Question 1

List of dwarfing apple rootstocks and the virus free (EMLA) counterpart; (3)

Answer 1

Malling 27 - EMLA 27
Malling 9 - EMLA 9
Malling 26 - EMLA 26

Question 2

Most significantly dwarfing rootstock;

Answer 2

Malling 27 (with virus).

Question 3

Characteristics of Malling 27;

Answer 3

Produces Tree’s 1.5m-2m tall.
Good for high density planting.
Can be used as an inter stock.

Question 4

Malling 9 characteristics;

Answer 4

Originated as a chance seedling in France.
Seldom over 3m
Can be used as an inter stock (limited dwarfing)
Requires support
Susceptible to wooly apple aphid.

Question 5

Malling 7a Characteristics (4)

Answer 5

Semi dwarfing rootstock.
tol-erant of excessive soil moisture, but susceptible to crown gall.
Well-anchored staking is required for the first few years.
suckers badly, and the trees are not very winter-hardy.
(Suggested tree spacing is 4.2 4.8 m (14 16 ft))

Question 6

‘Malling 26 Characteristics (5)

Answer 6

• a cross between ‘Malling 16’ and ‘Malling 9.’
• larger and sturdier than ‘Malling 9’.
• quite winter-hardy,
• does not tolerate heavy or poorly drained soils,
• Susceptible to fire blight (Erwinia amylovora) but less to collar rot

Question 7

‘Malling-Merton 106.’

Answer 7

• susceptible to crown rot (Phytophthora)
• The roots are well anchored and do not sucker.
• not resistant to early fall freezes

Question 8

Malling-Merton 111.’ (4)

Answer 8

• highly vigorous Rootstock
• It does well on a wide range of soil types.
• susceptible to mildew - not susceptinle to collar rot or woolly aphid.

Question 9

Robusta No. 5 Characteristics (4)

Answer 9

• vigorous
• very hardy clonal apple rootstock
• strong compatability
• It is the best rootstock for use where extreme winter-hardiness is required.