Apple Rootstock Identification

There is a wide range of apple rootstocks in Australia. These rootstocks each have a characteristic effect on the scion variety growing on top. Seedling rootstocks (for example, Granny Smith open pollinated seedlings), although used for the rootstock, are variable in growth and are more susceptible to stress conditions, such as the effects of drought on fruit size. They are also very mildew susceptible.

Most of the rootstocks now used are clonal and have to be propagated vegetatively, by means of cuttings, in stool beds or layer beds.

Each particular rootstock affects the tree vigour and final tree size. The development of fruiting of the scion variety is also affected, as those grafted to dwarfing rootstocks tend to be more precocious. Scion fruit quality can be affected (maturity hastened or delayed, fruit size enhanced, colour improved); however, this may be because of the tree size and foliage canopy density. Some rootstocks are more resistant or susceptible to certain pests or diseases.

All rootstocks described here are different varieties of apple (Malus domestica Borkh.), and can be recognised by their variety characteristics. Some newer rootstocks bred for disease and pest resistance have used other species of Malus, but they are not yet commercially available in Australia. This Agfact describes the major rootstocks in Australia and their uses, including some new and only recently available rootstocks.

Major rootstocks used in Australia

Information is available for each of the following rootstocks (includes photographs of the branch and leaf):

• Budagovsky 57-490 
  
• Doucin Vert M7 
  
• Jaune de Metz M9 
  
• M.25 
  
• M.26 
  
• M.27 
  
• Mark 
  
• Merton 778 
  
• Merton 779 
  
• Merton 793 
  
• MM.103 
  
• MM.104 
  
• MM.106 
  
• MM.109 
  
• MM.111 
  
• Northern Spy 
  
• Ottawa 3 
  
• P.1 
  
• P.18 
  
• P.2 
  

VS - very susceptible S - susceptible MS - moderately susceptible MR - moderately resistant R - resistant ? - not known

Comparison of rootstock size and vigour

Source:- Apple Root Stock