Sources
- Louis Lorette, The Lorette System of Pruning (original French publication 1914, English trans. 2nd edition 1920s – not yet sourced)
- Paul Champagnat, The Pruning of Fruit Trees (1954 edtn. trans. N. B. Bagenal)
- A. H. Lees, ‘Summer Pruning of Hard Fruits’, article for the 1934 RHS Conference on Apples and Pears
Origin
1914 publication of The Lorette System of Pruning.
According to Champganat, was popularised by Georges Truffaut in Jardinage (magazine? book?) and A.H. Lees of the Long Ashton Research Station contributed a paper on the Lorette System c. 1920 to Long Ashton Annual Report and to the 1934 RHS Conference on Apples and Pears (online source).
“We must be grateful to Truffaut and Hampe, who took up [Lorette’s] ideas again in 1941 and gave them a more modern setting.” {in L’Art de Tailler les arbres et les Plantes?}
Paul Champagnat, The Pruning of Fruit Trees p. 122
“Lorette’s book was translated into English by W. R. Dykes in 1925 and a second edition, revised by F. J. Chittenden, was published by John lane in 1946, with the addition of A. H. Lees’ 1934 paper. No one should try the system in England without reading both these.”
N.B. Bagenal’s translator’s note in Champagnat’s The Pruning of Fruit Trees p. 122.
Overview
“Lorette practised a very severe summer shortening of the wood shoots which he cut back to two leaves, about 1/2 in. (1cm) from their base. This produced later in the season a tardy development of latent buds into beak shoots, brindilles, dards or fruit buds. Whereas Desbois practised one single summer pruning, Lorette did severl between June and September. The September pruning differed from the rest in that it was more a matter of trimming up than actual pruning.”
Paul Champagnat, The Pruning of Fruit Trees p. 123
Technique
Leader Pruning
Carried out in Spring. “Lorette claimed … there was a better distribution of sap between the buds, and less tendency to annulation in the basal buds … it was possible to preserve the leading shoot at greater length and so form the tree more rapidly … Where the basal bud showed no tendency to be annulled the leader shoot was retained almost full length … an excellent way of using up excess sap and producing dards or brindilles. Where the basal buds did show a tendency … the top half of the leading shoot was cut off. In fully-established trees the leader was cut hard back to base.”
Paul Champagnat, The Pruning of Fruit Trees p. 123
Treatment of the Maiden Laterals
Paul Champagnat, The Pruning of Fruit Trees p. 123 – 129
“The Lorette system claimed to lead rapidly to fruit-bearing whilst at the same time allowing rigid formation of the tree. Summer pruning began at the earliest stage of formation pruning while the tree still retained its normal tendency to grow strong shoots.” (ibid, p.123)
First Pruning: end of June to early July.
No fixed date, based on observation, varies by region and shoot development. Carried out once shoots have grown to “thickness of an ordinary lead pencil”, estimated at 1/5 of an inch (approx. 5mm). Cut back shoot above first two leaves. Intended to develop the “axillary and stipulary” buds, which should grow into “a very small extension, a mere pad … from a fraction of an inch to a little more than one inch. As it is now the middle of summer, growth soon ceases, the minute shoots usually terminating in a dard. Thus a few weeks after pruning, an appreciable result is obtained, last year’s shoots being already provided with fruiting organs, According to his own statements, Lorette himself used to obtain numerous fruit buds.” (ibid, p. 125)
Second Pruning: end of July to early August.
Any shoots that have reached the appropriate thickness are pruned as above. Thinner shoots are left to produce long or short brindilles. The result of this later pruning is shorter dards.
Third Pruning: end of August to early September.
Prune any shoots that are now thick enough, leave the leader for pruning in following spring. Brindilles can be arched to encourage fruit buds (ibid, p.129).
Possible Failures
– Wood shoot development at pruning point = prune above third or fourth leaf in September, to prevent vigorous regrowth.
– No bud (dard) development = usually due to drought, should produce dards the following season.
– Blindness / annulation of dormant buds = prune carefully, only most vigorous shoots, treat medium shoots as brindilles.
More Complicated Cases
– Several wood shoots = prune above second leaf.
– One wood shoot, two dards = dards retained, prune wood shoot to one leaf.
– Two wood shoots, one dard = prune upper shoot to two or three leaves, lower to one leaf at first pruning.
Pruning of Older Spurs
Paul Champagnat, The Pruning of Fruit Trees p. 129 – 131
Treatment of the Dard
“[O]wing to the spring pruning of the leader … and the summer treatment of wood shoots … there is a tendency to produce a large number of dards. It is therefore a first necessity to make these develop rapidly into fruit-bearing organs, since under certain circumstances a dard can very easily grow into a wood shoot.” (ibid p. 129)
If the dard is strong and well-formed, it will usually have one or two wood shoots at the same point of origin, which should be pruned back to two or four buds depending on the tree’s vigour. “As a result there will be fresh wood shoots made at the expense of the buds that are left, and these valves (or sap-drawers) prevent the transformation of the dard into a shoot. This is merely a summer version of the three-bud winter pruning treatment of a similar case.” (ibid p. 129 – 130).
If the dard is weak, prune the other shoots right back. May still result in a wood shoot the following spring if the dard is not judged to be in the right condition.
Treatment of the Knob
Limit any “cumbersome” series of “knobs strung together” [‘bourse-on-bourse’ shoots] to two or three, to reduce formation of wood shoots, and cut back any wood shoots that do form to their base.
Pruning at the Beginning of September
Paul Champagnat, The Pruning of Fruit Trees p. 131
“…these operations replace all winter pruning in the Lorette system … all superfluous wood is cut back.”
– Shoots left a few inches long are cut back as near as possible to main branch.
– Dard on which a fruit bud has formed is cut back to fruit bud.
“He [Lorette] maintained that the small amount of time during which the tree continues growing after this results in too small a supply of sap to make the buds start into wood growth, but sufficient to make them develop into static fruit buds. The risk here is that, should growth cease before this happened, the following spring there would be in many cases a crop of wood shoots, and one year’s work would be lost.” (ibid, p. 131)
Discussion of the Lorette System
Paul Champagnat, The Pruning of Fruit Trees p. 132 – 133
Advantages
– Designed to bring into bearing trees that do not respond to short-spur or long-spur pruning because they are too vigorous.
– Admits plenty of light and air into the canopy; “research has shown that more floral embryos are formed on shoots that are open to the sunlight than on those in shade.” (ibid. p.132)
Disadvantages
– Criticism made: “suppression of such a large number of leaves, in the full flush of growth, must endanger the life of the tree” answered by: no more than 40% of foliage typically removed, examination of Lorette pruned trees shows leaves in good health.
– “… to put Lorette’s principles into practice successfully demands much common sense, great powers of observation, and skill in the progressive treatment of dards.” (ibid, p.132)
– Many axillary and stipulary buds remain dormant at point of pruning, “…due to unsuitable growth conditions, or the attempt to apply the Lorette system to trees that were already old, and that had previously been pruned by some different method.” (ibid p. 132)
– Lorette pruning is said to exhaust the tree due to over-cropping; Champagnat suggests that more fruit is better than less and manuring can be used to prolong the life of the tree.
– Very vigorous trees in the appropriate conditions are required to apply the method successfully: “Any really vigorous variety which produces wood shoots in large numbers can be pruned by the Lorette system. Heavy applications of manures should always be provided.” (ibid p. 133)
Glossary Links
Thoughts…
Champagnat makes it very clear that the Lorette System is only applicable to very vigorous trees that are also well-manured, in order to ensure they produce enough shoot growth.