A book for those interested in commercial apple tree pruning

Slightly off on a tangent, but an interesting one....

I've noticed that many substantially-tip-bearing varieties, when grown on M25 rootstock and where the maiden is left unpruned, will also fruit along the sides of last year's wood on the upper half of the stem in particular.
In other words: an unpruned maiden M25 tip-bearer will often carry a crop along its trunk in its second leaf somewhat resembling the ballerina. The top of the tree continues growing and forms the primary branches. The strong roots allow the tree to both grow and fruit at the same time.

The likes of Barnack Beauty, Irish Peach and Gascoyne's Scarlet come to mind, along with some of the tip-bearing pears such as Doyenne d'Ete, when grown on pear seedling stock or Pyrodwarf.

I think what's happening is that pruning suppresses fruit production due to altering the root:shoot equilibrium and affecting whether the tree directs all its energy to regrow what was pruned off (therefore refuses to fruit), or to produce fruit on an unpruned tree along the piece of wood that winter pruning would normally remove.
So an unpruned M25 (vigorous) will crop very early in life and quite heavily, while a hard-pruned M9 or M26 (dwarf or semi-dwarf) will have its cropping delayed by the imbalance cause by the pruning, yet without the pruning the tree will not grow fast enough.

An unpruned and unfed M25 is also much less troublesome for bitter pit than a hard-pruned, well-fed M9 or M26.

Also worth noting that I've seen some of my trees/bushes switch their large, hairy fruit buds over to shoot buds after hard winter pruning. On one occasion, with hard-pruning I managed to persuade a tree to convert all its blossom buds to new shoots. Where it would have borne a heavy crop from a large number of blossoms, the hard winter prune suddenly caused all those blossom buds to convert to shoot buds, no doubt due to a severe root:shoot imbalance.
It's not supposed to happen (I've never seen it mentioned in a book): a fruit bud is not supposed to switch itself to a shoot bud, but it does in my real world.

The opposite also appears to hold true: an unpruned stem, on a tip-bearing tree, on M25 rootstock, with what appears to be only the small, flattened, shoot/wood buds along its length, will "unexpectedly" convert some of those into blossom buds in the spring - hence the ability to crop a maiden M25 tip-bearer. But it only does this if it is not pruned.
Again, it's not supposed to happen, but it does for me.

I discovered this phenomenon because if I prune a MM111 or M25 maiden, I often end up with annoying narrow branch angles requiring more work. But it I leave the maiden unpruned the branch angles tend to be much wider - and therefore better angles and stronger for supporting a heavy crop in the trees' mature years with less risk of branch breakage or trunk splitting.

Note that among apples it only appears to be the M25 tip-bearing maidens which crop on their unpruned stem; I have never noticed a MM111 maiden crop along its unpruned main stem.

The entire purpose of the pruning techniques described in this book is to encourage early, continuous, and heavy fruiting, in the smallest amount of space, by always maintaining the balance of fruiting and growing. At no point is the tree pruned in such as way as to delay its fruiting, quite the opposite.

Needless to say, this is all achieved using dwarf trees.

One of the key points that comes across as you read the book is the crucial importance of light. It is needed not just to ripen the apples, but also to help growth and to encourage next year's fruit bud production. For those who lament the lack of English-grown apples in supermarkets, it is a salutory fact that countries such as New Zealand and Chile are able to achieve almost double the yields per tree that we are in the UK simply because of better light intensity.

Agreed. The need for light and warmth are under-estimated. A little - but not too much - thirst and hunger improve the quality of the fruit too.

Thirst and hunger encourage the tree to go into a "reproduce quickly in case I die", which increases blossom bud formation for the following year. Trees which are very sick and close to death will often put on one final magnificent blossom display before collapsing and dying later that year.
Dwarf rootstocks (M27, M9, M26, Quince for pears and St.Julien for plums) achieve a similar "I'm not feeling well" effect due to the semi-incompatibility at the graft where the scion and rootstock are reluctant to exchange water and nutrients from the roots for sugars from the leaves. So the slowed sap exchange keeps the tree slightly stressed and slows its growth - also trapping sugars in the leaves and shoots which also encourage flower bud formation.

Light and warmth are required for photosynthesis (hence sunny walls being popular for figs and grapes). It is the accumulation of high levels of sugars in the leaves and shoots which persuades the tree to use those sugars to produce fruit buds for the following year. A little drought stress also slows the flow of sap, causing accumulations in the leaves and shoots which encourage blossom bud formation for the following year.
Lots of sugars also mean better fruit growth and more fruit sweetness in the current season.

Unfortunately, aphids thrive on the sugary leaves of a tree in a sunny, mild, dry climate.

After a dull and wet year, trees may well not have had the warmth, sunshine and mild drought-stress required to encourage a heavy crop.

Some varieties cope much better than others with lack of sun and lack of warmth. Old Scottish varieties would, in many cases, have to cope with such conditions - and therefore could be ideal for someone with a rather shaded garden. The variety "Scotch Bridget" has a reputation for never failing to produce a good crop even in cold, wet, dull seasons and even when pollination is poor. I think Gravenstein and Jargonelle (pear) also cope well with semi-shade and cooler weather, as does Ashmead's Kernel as long as pollination is adequate.
"Foreign" mild-climate varieties (such as Golden Delicious) may not form fruit buds at all in many years in parts of the UK.
I've experimented with a Golden Delicious alongside a Grenadier in a three-quarter-shade spot and the Golden Delicious will not flower yet the Grenadier produces plenty of blossom and a good crop every year.

It is easy to forget just how far north the UK is. Although the Gulf Stream keeps our climate mild, it also brings the cloud and rain that suppresses light levels. This is the main reason why new world apples can be difficult in our climate, they expect a warmer growing season and much better light levels. For example, Toronto, in Canada, is at the same latitude as the south of France.

The higher-altitude and Western parts of the UK tend to bear the brunt of the rain (and hence dark cloud) but the lower-lying areas, coastal areas and South-Eastern areas tend to have less rain, less cloud, higher light levels and often the warm air of summer blowing off the continent.

Cloud and rain tend to be greatest the higher the altitude and the closer to the Atlantic, and least at lower altitude and furthest from the Atlantic ocean.
It's well worth looking at the rainfall hourly snapshots from the Met Office radar to see how the rain fizzles out as it goes from West to East across the UK, especially as it travels from Wales across to East Anglia:
Rainfall radar - Met Office

Also here are UK climate summaries, which may also be useful for determining what might do well:
http://www.metoffice.gov.uk/climate/...ukmapavge.html

Although South-Western areas have a longer growing season, their peak daytime summer temperature is lower than East Anglia and the SouthEast. Warmth helps plants grow earlier and better in the same way as growing in a greenhouse gets plants going earlier in the year and ripens the crop earlier. Hence why it's not unusual for me to be among the first on here to have ripe apples from Beauty of Bath (mid-late July) and Discovery (late-July to early-August) whereas others on here are a week or two later.
Often the autunm sunshine is less in the SouthWest than in East Anglia and the SouthEast, making it less easy to perfectly ripen the really late apples in the SouthWest unless quite close to the milder and sunnier coast.

So the SouthEast, East of England and lower-lying coastal areas have a good chance of growing "foreign" varieties.
Sturmer Pippin and D'Arcy Spice are varieties which need a hot dry climate, doing well in Australia and milder regions, and also doing well in East Anglia because of the "continental" climate and mild autumns - but not doing so well in wetter, cooler and duller regions.

Apple seedling trees are quite rare in this area, but not far from me is a fine Granny Smith* lookalike seedling (looks like diploid rather than triploid) which, although biennial and suffering from some mild scab, it is a very happy looking and quite large tree.

*Fruit closely resembles Granny Smith; colour is green with whitish specks (lenticels) and very little in the way of orange-red-brown flush. Fruit turns to yellow-green when really ripe. Fruit ripens in November - still hanging on the tree in December. Fruit is crisp, juicy, sweet-sharp, only slightly aromatic.

Thanks for reviewing this. I saw it mentioned by the English Apple Man and initially considered it would be too detailed for me. But, as a second rate pruner, I think I'll order a copy and try to up my game next year.