Apple rootstock yields?

[clv101]

This spring I grafted a few apple trees on a variety of rootstocks. I used M9, MM106, MM111 and I also did some MM111/M9 interstem.

There are two things are curious about and I'm having trouble finding reliable data on-line. Firstly, what eventual yield can I expect from these trees and secondly, more importantly too, when will they come into fruit and how quickly will their yield increase over the their first 10 years?

From Wikipedia, but lacking citation we have:
M9 23-29 kg after 5 to 6 years
MM106 41-50 kg after some 7 or 8 years
MM111 73 to 163 kg after 8 to 9 years

This site gives the following mature yields:
M9 10-20 kg
MM106 25-50 kg
MM111 50-150 kg

This random link says:
MM106 40-50 kg
MM111 75-160 kg

Can anyone point me towards good data of this kind? Maybe from academic publications or a book?

[boundtothesoil]

You could try orangepippin's site as there's lots of information
Expert help and advice on choosing and growing fruit trees

Or fruitforum
Fruit Forum | A webspace for fruit enthusiasts

Or the site below which has loads of articles
English Apples and the Leicestershire Heritage Apples Project, DIVERSITY

MAFF technical bulletin no. 207 'Apples' (1971) has a shortish section on the different characteristics of rootstocks, and a longer discussion can be found in MAFF bulletin no. 135 'Fruit Tree Raising' (1968). Both can be found on A****N, but neither give specific maximum yields or times to maximum yields, either generally or by variety (probably because these will vary widely depending on loads of factors).

[FB.]

Different rootstocks don't give the same results in all locations. Climate, soil type, subsoil type, rainfall/irrigation, type of pruning, feeding, spraying, mulching, grass cover, nearby plants or growing in clear/open ground all make a big difference. The scion variety will have an effect too; some crop heavily, some crop lightly, some are erratic and some are biennial.

Rootstocks - and scion varieties for that matter - have distinct preferences or dislikes when it comes to all the above.

In my region (East Anglia), apple trees - even on very vigorous rootstocks - were never grown as full standards because the trees were never able to grow as large in our dry climate as they would if planted in South-West England where there is twice the rainfall. So the West Country grow their trees as standards but we grow them as half-standards. What would be a half-standard in the West Country makes a bush here. What makes a bush in the West Country makes a dwarf bush or cordon here.

Some varieties/rootstocks thrive in wet climates while others thrive in dry climates. Some like hot climates and some like cool climates.
MM106 rootstock does well in cool, damp soil but easily dies on light dry hot soils; it may out-grow and out-crop MM111 in those conditions. But in a hot dry climate MM111 will reach twice the size and be about four times more productive than MM106. Those are just a couple of examples.
Similarly, Grenadier does well in a wet climate while Tydeman's Late Orange does well in a dry climate. So a MM106 Grenadier would outperform a MM111 Tydeman's Late Orange in the West, but would be much less happy in the East.

I've noticed other quirks, too. To name just a few examples: I experimented with a Hambledon Deux Ans on MM111 rootstock. It preferred a light, alkaline soil (sandy-chalky). On the other hand, Annie Elizabeth on MM106 rootstock preferred a heavy acid soil (clay).
Yet more quirks: Edward VII and Laxton's Epicure - and the rootstock M25 - are monstrously fast growing compared to other varieties in warm summers, but in cool summers they don't grow much at all; MM106 - and especially M116 - will do better than M25 in cold damp summers.
Last quirk: MM111 - and the scion variety Jupiter - seem very 'in-tune' with the climate. They have an uncanny knack of 'knowing' when there will be a hard winter and shut down growth much earlier than expected as they 'harden off' in good time before the winter. This means less growth than MM106 or M25 in some years - but also less risk of winter freeze damage to the young shoots. It is not unusual for my M25 Edward VII to still have half its leaves in January, yet my M25 Jupiter in 2011 and 2012 dropped all its leaves by the end of September.

The best way to judge what to expect is to look at your soil and climate and take into account how you plan to manage the trees.

[orangepippin]

There is a clue to the problem in the very wide range of yields you are quoting. As FB has pointed out, the number of variables involved is simply too great in the home orchard environment to be meaningful. All you can really say is that trees on the more vigorous rootstocks will probably be bigger (most of the time) and yield per area will probably be greater (but not all the time) for the more dwarf rootstocks.

The only accurate data is that available for commercial varieties grown on dwarf rootstocks and trained intensively. At this level yields can be predicted with considerable accuracy for the 1st, 2nd, 3rd and subsequent years. However even here climate has a major impact, with a modern English orchard only able to achieve just over half the yield of a similar orchard in New Zealand.