Frequently asked questions about clonal rootstocks:
What does “clonal” mean? In short, cloning a plant is the process of creating several, identical plants from one mother plant. At Duarte Nursery, we use clonal technology to reproduce the best rootstocks. The Mother tree is one tree selected from many, it will display desirable traits such as: higher production, suitability to a specific soil type, resistance to nematodes and root pathogens, or the increasingly-important characteristic of salt tolerance. For the farmer, this means that every cloned tree can grow and produce like the “best” tree!
Q: What is a clonal rootstock?
A: A clonal rootstock is a vegetatively propagated or cloned rootstock as opposed to a germinated seedling rootstock. You carefully select a clonal variety to have your trees budded to. now you can carefully select a clonal rootstock also. A clonal rootstock is not a GMO (Genetically Modified Organism) in any way.
Q: Why is it important to understand clonal rootstocks?
A: Clonal rootstocks allow you to better select the genetics of your orchard. Clonal root-
stocks are more productive, uniform, disease resistant, and adaptable.
Q: How do clonal rootstocks deliver these advantages?
A: Through more precise genetic selection. This is a big advantage for several reasons -
1 - Clonal rootstocks are selected for specific traits rather than general characteristics.
Whereas seedling rootstocks are selected for the general characteristics of a given number
mother tree to produce similarly performing seedlings, Clonal rootstocks are selected as spe-
cific seedlings with the best combination of desired traits. This is like selecting the best tree
from a strong orchard and bringing the whole orchard to that level.
2 - Clonal selection allows us to access diverse parents for an optimum combina-
tion of traits. An example is Hansen (peach x almond) hybrid where the positive traits of each
parent can be selected for. By crossing peach and almond parents, UC breeders combined
peach traits of nematode resistance and moist soil tolerance with almond traits of deep roots,
salt tolerance and vigor.
As a seedling population, the diverse parents produced a group of rootstock seedlings too di-
verse in combined characteristics to make a good commercial rootstock. Some seedlings
had the best of each parent, some the worst and many with combinations in between. The
one seedling with ideal traits was Hansen. Production trials and grower experience validate
the advantages of clonal Hansen.
In fact – in crops where clonal rootstocks are broadly available, seedling rootstocks are either
unheard of or fading fast.
Q: Where can I learn more and order my trees with clonal rootstocks?
A: Duarte Nursery!
