Topworking vs. single graft on rootstock?

[CherimoyaDude]

I was curious what the pros and cons of these two methods are. Is there any reason to topwork besides wanting multiple varieties of fruit on the same plant? Is it harder to graft higher on the plant?

[spaugh]

Less grafts is less work.  You can always graft onto another graft.  Or let the rootstock branch and do several at once.  If you let it get too large and have to do 20 grafts its going to be a pain. 

[simon_grow]

Brad and I have been doing lots of top working larger trees and single, double or multigrafting smaller younger trees. Single or double grafting smaller seedlings is easier because you only have to get a couple grafts to take and as the tree matures, the whole tree becomes those varieties you grafted.

Top working a tree is a pain in the ass because of all the grafts(scions) that must be used. Usually on a mature tree, you will have to graft onto the smaller outer branches in order to match the diameter of the scions. Because of this, only the outer canopy becomes the new variety and the fruiting wood moves up each year. These high grafted branches can easily be accidentally trimmed off if not careful.

If a tree is topworked with multiple varieties, it becomes difficult to tell what variety of fruit or scions you harvest off the tree. I know I have received several miss identified scions that were harvested from multigraft trees and we are now extremely paranoid about getting properly identified varieties.

When I do volunteer work for my elderly friends, I often top large trees to 24-32 inches and either bark graft or wait till new branches form from below the cut and graft a few of the new branches, usually in Spring.

With top worked trees, you also have to worry about rootstock branches coming up.

Simon

[venturabananas]

I agree with everything Brad and Simon said, and would add that "balancing" multiple varieties on a single tree also takes extra work.  By that, I mean having to prune back vigorous varieties harder than slower growing varieties to keep the vigorous ones from taking over a multi-grafted tree.  I was just doing some of that on an avocado.

[Orkine]

As previously noted, it depends on what you have to work with and what you are trying to accomplish.
A small seedling will likely give you a single graft site or two. Ideal for making a clone of a particular variety.
A mature tree being top worked will very likely give you multiple graft sites.  Often allows multiple varieties on the same tree although multiple grafts of the same variety can be made.

I have done both and would use whichever as appropriate depending on my situation is.

[Finca La Isla]

If you top work by cutting way back and grafting onto the new sprouts then the tree will develop way faster than the small seedling since it already has a developed root system.  This is a big advantage when appropriate.

[simon_grow]

Finca la isla has a great point as well.

In an ideal situation, the rootstock tree has nice scaffold branches evenly spaced at the proper height.

If it has 3 or 4 main scaffold branches, you only need to put on 1-2 grafts per branch after you cut back the scaffold branches. Unfortunately, most the larger trees I’ve been asked to topworked are larger seedling trees which were not shaped when younger so they are Christmas tree shaped with scaffold branches starting around 6-7 feet or higher. Grafting at these heights is a pain.

I’m lazy so I often end up cutting back unkept trees to knee level and then bark grafting.

Simon

[FruitFreak]

Depends on the size of the rootstock.  Obviously it’s easier/cheaper to do one graft opposed to 3 or 6 or more but if your rootstock is more developed than you have to topwork.