Definition - What does Interstem mean?
In the area of plant grafting, an interstem is an intermediate plant part that is used to aid in grafting trees together. The interstem is a plant part that is compatible with both the “scion” and the “rootstock”.
This compatibility between the separate pieces allows the graft to be stronger, and have a higher success rate in growth and development.
Interstem can also be referred to as interstock.
MaximumYield explains Interstem
In the process of grafting trees, the tissues of plants are joined so they continue their growth together. The upper part of the plant is called the scion, and the lower part is called the rootstock.
Occasionally, the two trees being joined together may lack enough compatibility to grow successfully. It is in these instances where an interstem is important. Additionally, trees grafted together with the use of an interstem can have a much higher resistance to disease and cold.
The interstem method of grafting provides several additional advantages. Growers can use a healthy, full-sized root system for the rootstock and combine it through an interstem with a particular fruit variety.
An interstem will also cause dwarfing in the tree. This is another positive aspect as dwarfed trees bear at a younger age, and can give higher yields per acre. However, dwarfed trees do tend to be shorter lived than their non-dwarfed counterparts.