The Clonal Rootstocks: Short Story
Grafting of fruit cultivars upon clonal rootstock has a long tradition, but untill well into the twentieth century there was little sound knowledge on this issue. There were several rootstocks type bore  the name  ‘Paradise’  by one way or other. Growers used these types without much questioning ,although they differed quite considerably in behavior. The first scientific efforts undertaken at the English ‘Why college fruit experiment station’ at East Malling in late ninetieth and beginning of twentieth century.

grows in the temperate region of the world (Areas that don’t get too hot or too cold) apple trees are best adapted to areas where average winter temperature is near freezing for at least two months.

Available Apple Rootstocks
MM111(Malling Merton) 20-24 ft; good growth when young, heavy cropper. Tolerates latent apple viruses and all soils, ‘including waterlogged’ (though waterlogged ground is never to be recommended as wet conditions increase scab and canker risks.). Hardy, also drought resistant, excellent anchorage but early loss of leaves.80-85% in size .Takes 3-4 years in fruiting. Suitable to replant.

MM106
The most useful garden stock. It makes a tree about 8-12 ft high at 8 years old, vertical growth is very little after 8-9 years. Good for weak-growing and spur varieties; takes 3-4 years to bear fruit; can be used for cordons, espaliers and fans; resistant to latent apple viruses; excellent anchorage not good in wet soils. Plant 12-15 ft apart .But susceptible to collar rot. Size is 60-65 % of standard tree. Comes into sample within three year.

M4
The most useful garden stock. It makes a tree about 8-12 ft high at 8 years old, vertical growth is very little after 8-9 years. Good for weak-growing and spur varieties; takes 3-4 years to bear fruit; can be used for cordons, espaliers and fans; resistant to latent apple viruses; excellent anchorage not good in wet soils. Plant 12-15 ft apart .But susceptible to collar rot. Size is 60-65 % of standard tree. Comes into sample within three year.

M7
It does not bear an old name It proved to be a semi-dwarfing and precocious rootstock in the old trials. It is still widely used in western countries. At Rohanda in Mandi District an orchard on M7 and M9 is established in 1972 which is still doing well and plants still looks young. It gives regular crop and tree is well manageable .It is also a good competitor to MM106.. size 60-65%, comes into production within 3-4 years

M9
It is known best of the Malling series and still expanding in the world. Tree on M9 have continued to crop heavily and also maintain healthy growth throughout the period .The fruit on M9 is good color. It needs stake for 6/7 yrs ; hardy, avoid clay soils and wet ones, 2-3 years to bear. In drought irrigation is required.

Malling Immune 793
Became very popular due to its resistance to woolly apple aphid and replantation decease (SARD). It is a semi-vigorous tree with good rooting system. It is regular bearer and very suitable for replantation in old apple orchards. It is still very popular in south Africa, Brazil and some parts of New-Zealand . The size is 80-90% of seedling and comes into production within 4 years.

Rootstock breeding : 
The next step was to make improvements through breeding and again England took the lead. The aim was to find rootstock resistant to woolly apple aphid ,a noxious insect on apple roots. collaborated efforts between East Malling and the John Inn Institute ,Merton started in 1922 and intensified in 1928, leading to Merton Immune series (MI778-793) in 1930 and Malling Merton series(MM101-115) in the 1950.All were resistant to woolly apple aphid. In Malling Immune series only MI793 became populardue to its resistence to replant problems i.e. SARD

Inter-stem :
Some of the shortcomings of rootstocks can be (partly) solved by inserting a third cultiver between the rootstock and scion . the stem piece is called interstem or interstock. Interstems are mainly used to control the size of the cultivars, and for compatibility problems between rootstock and scion.

High Budding : 
Increasing the height of budding or grafting on a rootstock may reduces the growth later on . Although the degree of reduction depends on the scion cultivars.

Fruit quality : 
Rootstock differ in uptake of minerals from the soil so there is difference in fruit quality in every different rootstock .

Never use spur type cultivar on dwarf rootstock unless planted in very very high density

Rootstock evaluation :
For a fruit grower, it is utmost importance to choose the right rootstock. The establishment of an orchard is a large investment that has to be earned back, preferably as soon as possible. A mistake in the complex scion-rootstock-planting distance is costly. If the planting distance is too large the orchard will never be very productive, if too small a dense plantation results leading to extra work and poor quality. So, the grower must be well advised. Rootstock comparison in nearby orchard can provide the right information.

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